1IPSEC.CONF(5) Executable programs IPSEC.CONF(5)
2
6 ipsec.conf - IPsec configuration and connections
7
9 The ipsec.conf file specifies most configuration and control
10 information for the Libreswan IPsec subsystem. (The major exception is
11 secrets for authentication; see ipsec.secrets(5).) Its contents are not
12 security-sensitive. Configurations can be added using this
13 configuration file or by using ipsec whack directly. This means that
14 technically, the ipsec.conf file is optional, but a few warnings might
15 show up when this file is missing.
16 ipsec.conf is a text file, consisting of one or more sections. White
18 space followed by # followed by anything to the end of the line is a
19 comment and is ignored, as are empty lines that are not within a
20 section.
21 A line that contains include and a file name, separated by white space,
23 is replaced by the contents of that file, preceded and followed by
24 empty lines. If the file name is not a full pathname, it is considered
25 to be relative to the directory that contains the including file. Such
26 inclusions can be nested. Only a single filename may be supplied, and
27 it may not contain white space, but it may include shell wildcards (see
28 sh(1)); for example:
29 include /etc/ipsec.d/*.conf
31 The intention of the include facility is mostly to permit keeping
33 information on connections, or sets of connections, separate from the
34 main configuration file. This permits such connection descriptions to
35 be changed, copied to the other security gateways involved, etc.,
36 without having to constantly extract them from the configuration file
37 and then insert them back into it. Note also the also and alsoflip
38 parameters (described below) which permit splitting a single logical
39 section (e.g. a connection description) into several distinct sections.
40 The first significant line of the file may specify a version of this
42 specification for backwards compatibility with freeswan and openswan.
43 It is ignored and unused. For compatibility with openswan, specify:
44 version 2
46 A section begins with a line of the form:
48 type name
50 where type indicates what type of section follows, and name is an
52 arbitrary name that distinguishes the section from others of the same
53 type. (Names must start with a letter and may contain only letters,
54 digits, periods, underscores, and hyphens.) All subsequent non-empty
55 lines that begin with white space are part of the section; comments
56 within a section must begin with white space too. There may be only one
57 section of a given type with a given name.
58 Lines within the section are generally of the form
60 parameter=value
62 (note the mandatory preceding white space). There can be white space on
64 either side of the =. Parameter names follow the same syntax as section
65 names, and are specific to a section type. Unless otherwise explicitly
66 specified, no parameter name may appear more than once in a section.
67 An empty value stands for the system default value (if any) of the
69 parameter, i.e. it is roughly equivalent to omitting the parameter line
70 entirely. A value may contain white space only if the entire value is
71 enclosed in double quotes ("); a value cannot itself contain a double
72 quote, nor may it be continued across more than one line.
73 Numeric values are specified to be either an “integer” (a sequence of
75 digits) or a “decimal number” (sequence of digits optionally followed
76 by `.' and another sequence of digits).
77 There is currently one parameter that is available in any type of
79 section:
80 also
82 the value is a section name; the parameters of that section are
83 appended to this section, as if they had been written as part of
84 it. The specified section must exist, must follow the current one,
85 and must have the same section type. (Nesting is permitted, and
86 there may be more than one also in a single section, although it is
87 forbidden to append the same section more than once.) This allows,
88 for example, keeping the encryption keys for a connection in a
89 separate file from the rest of the description, by using both an
90 also parameter and an include line. (Caution, see BUGS below for
91 some restrictions.)
92 alsoflip
94 can be used in a conn section. It acts like an also that flips the
95 referenced section's entries left-for-right.
96 Parameter names beginning with x- (or X-, or x_, or X_) are reserved
98 for user extensions and will never be assigned meanings by IPsec.
99 Parameters with such names must still observe the syntax rules (limits
100 on characters used in the name; no white space in a non-quoted value;
101 no newlines or double quotes within the value). All other as-yet-unused
102 parameter names are reserved for future IPsec improvements.
103 A section with name %default specifies defaults for sections of the
105 same type. For each parameter in it, any section of that type that does
106 not have a parameter of the same name gets a copy of the one from the
107 %default section. There may be multiple %default sections of a given
108 type, but only one default may be supplied for any specific parameter
109 name. %default sections may not contain also or alsoflip parameters.
110 Currently there are two types of section: a config section specifies
112 general configuration information for IPsec, while a conn section
113 specifies an IPsec connection.
114
116 A conn section contains a connection specification, defining a network
117 connection to be made using IPsec. The name given is arbitrary, and is
118 used to identify the connection to ipsec_auto(8) Here's a simple
119 example:
120 conn snt
123 left=10.11.11.1
124 leftsubnet=10.0.1.0/24
125 leftnexthop=172.16.55.66
126 leftsourceip=10.0.1.1
127 right=192.168.22.1
128 rightsubnet=10.0.2.0/24
129 rightnexthop=172.16.88.99
130 rightsourceip=10.0.2.1
131 keyingtries=%forever
132 A note on terminology... In automatic keying, there are two kinds of
134 communications going on: transmission of user IP packets, and
135 gateway-to-gateway negotiations for keying, rekeying, and general
136 control. The data path (a set of “IPsec SAs”) used for user packets is
137 herein referred to as the “connection”; the path used for negotiations
138 (built with “ISAKMP SAs”) is referred to as the “keying channel”.
139 To avoid trivial editing of the configuration file to suit it to each
141 system involved in a connection, connection specifications are written
142 in terms of left and right participants, rather than in terms of local
143 and remote. Which participant is considered left or right is arbitrary;
144 IPsec figures out which one it is being run on based on internal
145 information. This permits using identical connection specifications on
146 both ends. There are cases where there is no symmetry; a good
147 convention is to use left for the local side and right for the remote
148 side (the first letters are a good mnemonic).
149 Many of the parameters relate to one participant or the other; only the
151 ones for left are listed here, but every parameter whose name begins
152 with left has a right counterpart, whose description is the same but
153 with left and right reversed.
154 Parameters are optional unless marked “(required)”
156 CONN PARAMETERS: GENERAL
158 The following parameters are relevant to IKE automatic keying. Unless
159 otherwise noted, for a connection to work, in general it is necessary
160 for the two ends to agree exactly on the values of these parameters.
161 keyexchange
163 method of key exchange; the default and currently the only accepted
164 value is ike
165 hostaddrfamily
167 the address family of the hosts; currently the accepted values are
168 ipv4 and ipv6. The default is to detect this based on the IP
169 addresses specified or the IP addresses resolved, so this option is
170 not needed, unless you specify hostnames that resolve to both IPv4
171 and IPv6. This option used to be named connaddrfamily but its use
172 was broken so it was obsoleted in favour or using the new
173 hostaddrfamily and clientaddrfamily.
174 clientaddrfamily
176 the address family of the clients (subnets); currently the accepted
177 values are ipv4 and ipv6. The default is to detect this based on
178 the network IP addresses specified or the network IP addresses
179 resolved, so this option is not needed, unless you specify names
180 that resolve to both IPv4 and IPv6.
181 type
183 the type of the connection; currently the accepted values are
184 tunnel (the default) signifying a host-to-host, host-to-subnet, or
185 subnet-to-subnet tunnel; transport, signifying host-to-host
186 transport mode; passthrough, signifying that no IPsec processing
187 should be done at all; drop, signifying that packets should be
188 discarded; and reject, signifying that packets should be discarded
189 and a diagnostic ICMP returned.
190 left
192 (required) the IP address or DNS hostname of the left participant's
193 public-network interface, Currently, IPv4 and IPv6 IP addresses are
194 supported. If a DNS hostname is used, it will be resolved to an IP
195 address on load time, and whenever a connection is rekeying or
196 restarting (such as when restarted via a DPD failure detection).
197 This allows one to use a DNS hostname when the endpoint is on a
198 dynamic IP address.
199 There are several magic values. If it is %defaultroute, left will
201 be filled in automatically with the local address of the
202 default-route interface (as determined at IPsec startup time); this
203 also overrides any value supplied for leftnexthop. (Either left or
204 right may be %defaultroute, but not both.) The value %any signifies
205 an address to be filled in (by automatic keying) during
206 negotiation. The value %opportunistic signifies that both left and
207 leftnexthop are to be filled in (by automatic keying) from DNS data
208 for left's client. The value can also contain the interface name,
209 which will then later be used to obtain the IP address from to fill
210 in. For example %ppp0. The values %group and %opportunisticgroup
211 makes this a policy group conn: one that will be instantiated into
212 a regular or opportunistic conn for each CIDR block listed in the
213 policy group file with the same name as the conn.
214 If using IP addresses in combination with NAT, always use the
216 actual local machine's (NATed) IP address, and if the remote (eg
217 right=) is NATed as well, the remote's public (not NATed) IP
218 address. Note that this makes the configuration no longer
219 symmetrical on both sides, so you cannot use an identical
220 configuration file on both hosts.
221 leftsubnet
223 private subnet behind the left participant, expressed as
224 network/netmask (actually, any form acceptable to
225 ipsec_ttosubnet(3)); Currently, IPv4 and IPv6 ranges are supported.
226 if omitted, essentially assumed to be left/32, signifying that the
227 left end of the connection goes to the left participant only
228 It supports two magic shorthands vhost: and vnet:, which can list
230 subnets in the same syntax as virtual-private. The value %priv
231 expands to the networks specified in virtual-private. The value %no
232 means no subnet. A common use for allowing roadwarriors to come in
233 on public IPs or via accepted NATed networks from RFC1918 is to use
234 leftsubnet=vhost:%no,%priv. The vnet: option can be used to allow
235 RFC1918 subnets without hardcoding them. When using vnet the
236 connection will instantiate, allowing for multiple tunnels with
237 different subnets.
238 leftsubnets
240 specify multiple private subnets behind the left participant,
241 expressed as { networkA/netmaskA, networkB/netmaskB [...] } If
242 both a leftsubnets= and rightsubnets= are defined, all combinations
243 of subnet tunnels will be established as IPsec tunnels. You cannot
244 use leftsubnet= and leftsubnets= together. For examples see
245 testing/pluto/multinet-*. Be aware that when using spaces as
246 separator, that the entire option value needs to be in double
247 quotes.
248 leftvti
250 the address/mask to configure on the VTI interface when
251 vti-interface is set. It takes the form of network/netmask
252 (actually, any form acceptable to ipsec_ttosubnet(3)); Currently,
253 IPv4 and IPv6 ranges are supported. This option is often used in
254 combination with routed based VPNs.
255 leftaddresspool
257 address pool from where the IKEv1 ModeCFG or IKEv2 server can
258 assign IP addresses to clients. When configured as a server, using
259 leftxauthserver=yes this option specifies the address pool from
260 which IP addresses are taken to assign the clients. The syntax of
261 the address pool specifies a range (not a CIDR) for IPv4 and CIDR
262 for IPv6, in the following syntax:
263 rightaddresspool=192.168.1.100-192.168.1.200 or
264 rightaddresspool=2001:db8:0:3:1::/97 Generally, the
265 rightaddresspool= option will be accompanied by
266 rightxauthclient=yes, leftxauthserver=yes and leftsubnet=0.0.0.0/0
267 option.
268 When leftaddresspool= is specified, the connection may not specify
270 either leftsubnet= or leftsubnets=. Address pools are fully
271 allocated when the connection is loaded, so the ranges should be
272 sane. For example, specifying a range
273 rightaddresspool=10.0.0.0-11.0.0.0 will lead to massive memory
274 allocation. Address pools specifying the exact same range are
275 shared between different connections. Different addresspools should
276 not be defined to partially overlap.
277 leftprotoport
279 allowed protocols and ports over connection, also called Port
280 Selectors. The argument is in the form protocol, which can be a
281 number or a name that will be looked up in /etc/protocols, such as
282 leftprotoport=icmp, or in the form of protocol/port, such as
283 tcp/smtp. Ports can be defined as a number (eg. 25) or as a name
284 (eg smtp) which will be looked up in /etc/services. A special
285 keyword %any can be used to allow all ports of a certain protocol.
286 The most common use of this option is for L2TP connections to only
287 allow l2tp packets (UDP port 1701), eg: leftprotoport=17/1701.
288 To filter on specific icmp type and code, use the higher 8 bits for
290 type and the lower 8 bits for port. For example, to allow icmp echo
291 packets (type 8, code 0) the 'port' would be 0x0800, or 2048 in
292 decimal, so you configure leftprotoport=icmp/2048. Similarly, to
293 allow ipv6-icmp Neighbour Discovery which has type 136 (0x88) and
294 code 0(0x00) this becomes 0x8800 or in decimal 34816 resulting in
295 leftprotoport=ipv6-icmp/34816 .
296 Some clients, notably older Windows XP and some Mac OSX clients,
298 use a random high port as source port. In those cases
299 rightprotoport=17/%any can be used to allow all UDP traffic on the
300 connection. Note that this option is part of the proposal, so it
301 cannot be arbitrarily left out if one end does not care about the
302 traffic selection over this connection - both peers have to agree.
303 The Port Selectors show up in the output of ipsec eroute and ipsec
304 auto --status eg:"l2tp":
305 193.110.157.131[@aivd.libreswan.org]:7/1701...%any:17/1701 This
306 option only filters outbound traffic. Inbound traffic selection
307 must still be based on firewall rules activated by an updown
308 script. The variables $PLUTO_MY_PROTOCOL, $PLUTO_PEER_PROTOCOL,
309 $PLUTO_MY_PORT, and $PLUTO_PEER_PORT are available for use in
310 updown scripts. Older workarounds for bugs involved a setting of
311 17/0 to denote any single UDP port (not UDP port 0). Some clients,
312 most notably OSX, uses a random high port, instead of port 1701 for
313 L2TP.
314 leftnexthop
316 next-hop gateway IP address for the left participant's connection
317 to the public network; defaults to %direct (meaning right). If the
318 value is to be overridden by the left=%defaultroute method (see
319 above), an explicit value must not be given. If that method is not
320 being used, but leftnexthop is %defaultroute, and
321 interfaces=%defaultroute is used in the config setup section, the
322 next-hop gateway address of the default-route interface will be
323 used. The magic value %direct signifies a value to be filled in (by
324 automatic keying) with the peer's address. Relevant only locally,
325 other end need not agree on it.
326 leftsourceip
328 the IP address for this host to use when transmitting a packet to
329 the other side of this link. Relevant only locally, the other end
330 need not agree. This option is used to make the gateway itself use
331 its internal IP, which is part of the leftsubnet, to communicate to
332 the rightsubnet or right. Otherwise, it will use its nearest IP
333 address, which is its public IP address. This option is mostly used
334 when defining subnet-subnet connections, so that the gateways can
335 talk to each other and the subnet at the other end, without the
336 need to build additional host-subnet, subnet-host and host-host
337 tunnels. Both IPv4 and IPv6 addresses are supported.
338 leftupdown
340 what "updown" script to run to adjust routing and/or firewalling
341 when the status of the connection changes (default ipsec _updown).
342 May include positional parameters separated by white space
343 (although this requires enclosing the whole string in quotes);
344 including shell metacharacters is unwise. An example to enable
345 routing when using the NETKEY stack, one can use:
346 leftupdown="ipsec _updown --route yes"
348 To disable calling an updown script, set it to the empty string, eg
350 leftupdown="" or leftupdown="%disabled".
351 See ipsec_pluto(8) for details. Relevant only locally, other end
353 need not agree on it.
354 leftcat
356 Whether to perform Client Address Translation ("CAT") when using
357 Opportunistic IPsec behind NAT. Accepted values are no (the
358 default) and yes. This option should only be enabled on the special
359 Opportunistic IPsec connections, usually called "private" and
360 "private-or-clear". When set, this option causes the given
361 addresspool IP from the remote peer to be NATed with iptables. It
362 will also install an additional IPsec SA policy to cover the
363 pre-NAT IP. See the Opportunistic IPsec information on the
364 libreswan website for more information and examples.
365 leftfirewall
367 This option is obsolete and should not used anymore.
368 If one or both security gateways are doing forwarding firewalling
370 (possibly including masquerading), and this is specified using the
371 firewall parameters, tunnels established with IPsec are exempted from
372 it so that packets can flow unchanged through the tunnels. (This means
373 that all subnets connected in this manner must have distinct,
374 non-overlapping subnet address blocks.) This is done by the default
375 updown script (see ipsec_pluto(8)).
376 The implementation of this makes certain assumptions about firewall
378 setup, and the availability of the Linux Advanced Routing tools. In
379 situations calling for more control, it may be preferable for the user
380 to supply his own updown script, which makes the appropriate
381 adjustments for his system.
382 CONN PARAMETERS: AUTOMATIC KEYING
384 The following parameters are relevant to automatic keying via IKE.
385 Unless otherwise noted, for a connection to work, in general it is
386 necessary for the two ends to agree exactly on the values of these
387 parameters.
388 auto
390 what operation, if any, should be done automatically at IPsec
391 startup; currently-accepted values are add (signifying an ipsec
392 auto --add), ondemand (signifying that plus an ipsec auto
393 --ondemand), start (signifying that plus an ipsec auto --up), and
394 ignore (also the default) (signifying no automatic startup
395 operation), and keep (signifying an add plus an attempt to keep the
396 connection up once the remote peer brought it up). See the config
397 setup discussion below. Relevant only locally, other end need not
398 agree on it (but in general, for an intended-to-be-permanent
399 connection, both ends should use auto=start to ensure that any
400 reboot causes immediate renegotiation).
401 The option ondemand used to be called route
403 authby
405 how the two security gateways should authenticate each other;
406 acceptable values are rsasig (the default) for RSA authentication
407 with SHA-1, rsa-sha2 for RSASSA-PSS digital signatures based
408 authentication with SHA2-256, rsa-sha2_384 for RSASSA-PSS digital
409 signatures based authentication with SHA2-384, rsa-sha2_512 for
410 RSASSA-PSS digital signatures based authentication with SHA2-512,
411 secret for shared secrets (PSK) authentication, secret|rsasig for
412 either, never if negotiation is never to be attempted or accepted
413 (useful for shunt-only conns), and null for null-authentication.
414 If asymmetric authentication is requested, IKEv2 must be enabled,
416 and the options leftauth= and rightauth= should be used instead of
417 authby.
418 Digital signatures are superior in every way to shared secrets.
420 Especially IKEv1 in Aggressive Mode is vulnerable to offline
421 dictionary attacks and is performed routinely by at least the NSA
422 on monitored internet traffic globally. The never option is only
423 used for connections that do not actually start an IKE negotiation,
424 such as type=passthrough connections. The auth method null is used
425 for "anonymous opportunistic IPsec" and should not be used for
426 regular pre-configured IPsec VPNs.
427 ike
429 IKE encryption/authentication algorithm to be used for the
430 connection (phase 1 aka ISAKMP SA). The format is
431 "cipher-hash;modpgroup, cipher-hash;modpgroup, ..." Any left out
432 option will be filled in with all allowed default options. Multiple
433 proposals are separated by a comma. If an ike= line is specified,
434 no other received proposals will be accepted. Formerly there was a
435 distinction (by using a "!" symbol) between "strict mode" or not.
436 That mode has been obsoleted. If an ike= option is specified, the
437 mode is always strict, meaning no other received proposals will be
438 accepted. Some examples are ike=3des-sha1,aes-sha1, ike=aes,
439 ike=aes_ctr, ike=aes_gcm256-sha2, ike=aes128-md5;modp2048,
440 ike=aes256-sha2;dh19, ike=aes128-sha1;dh22,
441 ike=3des-md5;modp1024,aes-sha1;modp1536. The options must be
442 suitable as a value of ipsec_spi(8)'s --ike option. The default IKE
443 proposal depends on the version of libreswan used. It follow the
444 recommendations of RFC4306, RFC7321 and as of this writing their
445 successor draft documents RFC4306bis and RFC7321bis. For IKEv1,
446 SHA1 and MODP1536 are still allowed per default for backwards
447 compatibility, but 3DES and MODP1024 are not allowed per default.
448 IKEv2's minimum is AES, MODP2048 and SHA2. The default key size is
449 256 bits. The default AES_GCM ICV is 16 bytes.
450 Note that AES-GCM is an AEAD algorithm, meaning that it performs
452 encryption+authentication in one step. This means that AES-GCM must
453 not specify an authentication algorithm. However, it does require a
454 PRF function, so the second argument to an AEAD algorithm denotes
455 the PRF. So ike=aes_gcm-sha2 means propose AES_GCM with no
456 authentication and using SHA2 as the prf. Note that for phase2alg,
457 there is no prf, so AES-GCM is specified for ESP as
458 phase2alg=aes_gcm-null. The AES-GCM and AES-CCM algorithms support
459 8,12 and 16 byte ICV's. These can be specified using a postfix, for
460 example aes_gcm_a (for 8), aes_gcm_b (for 12) and aes_gcm_c (for
461 16). The default (aes_gcm without postfix) refers to the 16 byte
462 ICV version. It is strongly recommended to NOT use the 8 or 12 byte
463 versions of GCM or CCM.
464 Weak algorithms are regularly removed from libreswan. Currently,
466 1DES and modp768 have been removed and modp1024 will be removed in
467 the near future. Additionally, md5 and sha1 will be removed within
468 the next few years. Null encryption is available, and should only
469 be used for testing or benchmarking purposes. Please do not request
470 for insecure algorithms to be re-added to libreswan.
471 Diffie-Hellman groups 19,20 and 21 from RFC- 5903 and 22, 23 and 24
473 from RFC-5114 are also supported. For all groups, the "dh" keyword
474 can be used. For the MODP based groups, the modp= keyword can be
475 used. for example ike=3des-sha1;dh19. The RFC-5114 DH groups are
476 extremely controversial and MUST NOT be used unless forced
477 (administratively) by the other party. Support for these groups
478 will most likely be removed in 2017, as it cannot be proven these
479 DH groups do not have a cryptographic trapdoor embedded in them (a
480 backdoor by the USG who provided these primes without revealing the
481 seeds and generation process used). Due the the weakness of DH22,
482 support for this group is not compiled in by default and can be
483 re-enabled using USE_DH22=true.
484 The modp syntax will be removed in favour of the dh syntax in the
486 future
487 phase2
489 Sets the type of SA that will be produced. Valid options are: esp
490 for encryption (the default), ah for authentication only.
491 The very first IPsec designs called for use of AH plus ESP to offer
493 authentication, integrity and confidentiality. That dual protocol
494 use was a significant burden, so ESP was extended to offer all
495 three services, and AH remained as an auth/integ. The old mode of
496 ah+esp is no longer supported in compliance with RFC 8221 Section
497 4. Additionally, AH does not play well with NATs, so it is strongly
498 recommended to use ESP with the null cipher if you require
499 unencrypted authenticated transport.
500 phase2alg
502 This option is alias to esp.
503 sha2-truncbug
505 The default ESP hash truncation for sha2_256 is 128 bits. Some
506 IPsec implementations (Linux before 2.6.33, some Cisco (2811?)
507 routers) implement the draft version which stated 96 bits. If a
508 draft implementation communicates with an RFC implementation, both
509 ends will reject encrypted packets from each other.
510 This option enables using the draft 96 bits version to interop with
512 those implementations. Currently the accepted values are no, (the
513 default) signifying default RFC truncation of 128 bits, or yes,
514 signifying the draft 96 bits truncation.
515 Another workaround is to switch from sha2_256 to sha2_128 or
517 sha2_512.
518 ms-dh-downgrade
520 Whether to allow a downgrade of DiffieHellman group during rekey
521 (using CREATE_CHILD_SA). Microsoft Windows (at the time of writing,
522 Feb 2018) defaults to using the very weak modp1024 (DH2). This can
523 be changed using a Windows registry setting to use modp2048 (DH14).
524 However, at rekey times, it will shamelessly use modp1024 again and
525 the connection might fail. Setting this option to yes (and adding
526 modp1024 proposals to the ike line) this will allow this downgrade
527 attack to happen. This should only be used to support Windows that
528 feature this bug. Currently the accepted values are no, (the
529 default) or yes.
530 dns-match-id
532 Whether to perform an additional DNS lookup and confirm the remote
533 ID payload with the DNS name in the reverse DNS PTR record.
534 Accepted values are no (the default) or yes. This check should be
535 enabled when Opportunistic IPsec is enabled in a mode that is based
536 on packet triggers (on-demand) using IPSECKEY records in DNS. Since
537 in that case the IKE daemon pluto does not know the remote ID, it
538 only knows the remote IP address, this option forces it to confirm
539 the peer's proposed ID (and thus its public/private key) with its
540 actual IP address as listed in the DNS. This prevents attacks where
541 mail.example.com's IP address is taken over by a neighbour machine
542 with a valid web.example.com setup. This check is not needed for
543 certificate based Opportunistic IPsec, as "mail.example.com"s
544 certificate does not have an entry for "web.example.com". It is
545 also not needed for DNS server triggered Opportunistic IPsec, as in
546 that case the IKE daemon pluto is informed of both the IP address,
547 and the hostname/public key.
548 require-id-on-certificate
550 When using certificates, check whether the IKE peer ID is present
551 as a subjectAltName (SAN) on the peer certificate. Accepted values
552 are yes (the default) or no. This check should only be disabled
553 when intentionally using certificates that do not have their peer
554 ID specified as a SAN on the certificate. These certificates
555 violate RFC 4945 Section 3.1 and are normally rejected to prevent a
556 compromised host from assuming the IKE identity of another host.
557 The SAN limits the IDs that the peer is able to assume.
558 ppk
560 EXPERIMENTAL: Post-quantum preshared keys (PPKs) to be used.
561 Currently the accepted values are propose or yes (the default),
562 signifying we propose to use PPK for this connection; insist,
563 signifying we allow communication only if PPK is used for key
564 derivation; never or no, signifying that PPK should not be used for
565 key derivation. PPKs can be used in connections that allow only
566 IKEv2. In libreswan that would mean that ikev2 option must have
567 value insist. (currently based on draft-fluhrer-qr-ikev2, not
568 raft-ietf-ipsecme-qr-ikev2-00)
569 nat-ikev1-method
571 NAT Traversal in IKEv1 is negotiated via Vendor ID options as
572 specified in RFC 3947. However, many implementations only support
573 the draft version of the RFC. Libreswan sends both the RFC and the
574 most common draft versions (02, 02_n and 03) to maximize
575 interoperability. Unfortunately, there are known broken
576 implementations of RFC 3947, notably Cisco routers that have not
577 been updated to the latest firmware. As the NAT-T payload is sent
578 in the very first packet of the initiator, there is no method to
579 auto-detect this problem and initiate a workaround.
580 This option allows fine tuning which of the NAT-T payloads to
582 consider for sending and processing. Currently the accepted values
583 are drafts, rfc, both (the default) and none. To interoperate with
584 known broken devices, use nat-ikev1-method=drafts. To prevent the
585 other end from triggering IKEv1 NAT-T encapsulation, set this to
586 none. This will omit the NAT-T payloads used to determine NAT,
587 forcing the other end not to use encapsulation.
588 esp
590 Specifies the algorithms that will be offered/accepted for a Child
591 SA negotiation. If not specified, a secure set of defaults will be
592 used. Sets are separated using comma's and pluses.
593 The format for ESP is ENC-AUTH followed by one optional PFSgroup.
595 For instance, "aes_gcm256" or "aes256-sha2_512-dh14" or
596 "aes-sha2_512+sha2_256". When specifying multiple algorithms,
597 specify the PFSgroup last, e.g.
598 "aes128+aes256-sha2_512+sha2_256-dh14+dh19".
599 The format for AH is AUTH followed by an optional PFSgroup. For
601 instance, "sha2_512" or "sha2_256-dh14".
602 AEAD algorithms such as AES-GCM and AES-CCM don't require separate
604 hashing algorithm, for example esp=aes_gcm256 or esp=aes_ccm. Note
605 that the ike= syntax for aes_gcm does require the prf hashing
606 algorithm which is not needed for esp=. The supported key sizes for
607 aes_gcm are 128, 192 and 256, which are specified similarly to
608 plain aes, i.e. esp=aes_gcm256. A subscript of _c, _b or _a can be
609 used to refer to the different ICV variants where a means 8 bytes,
610 b means 12 bytes and c means 16 bytes. The default when not using a
611 subscript is the 16 byte ICV, the recommended value by RFC-4106 and
612 RFC-8247. Therefore esp=aes_gcm256 is equivalent to
613 esp=aes_gcm_c256. It is recommended to migrate to the _c versions
614 (without specifying _c), as support for smaller ICV's might be
615 removed in the near future.
616 The supported algorithms depend on the libreswan version, OS and
618 kernel stack used. Possible ciphers are aes, 3des, aes_ctr,
619 aes_gcm, aes_ccm, camellia and chacha20_poly1305.
620 Note that openswan and versions of libreswan up to 3.6 require
622 manually adding the salt size to the key size. Therefore, to
623 configure an older version of openswan or libreswan, use:
624 "esp=aes_ccm_c-280-null" to interop with a new libreswan using
625 "esp=aes_ccm256". For CCM, the 'keysize' needs to be increased by
626 24, resulted in valid keysizes of 152, 215 and 280. For GCM the
627 'keysize' needs to be increased by 32, resulting valid 'keysizes'
628 of 160, 224 and 288.
629 ah
631 AH authentication algorithm to be used for the connection, e.g
632 here. sha2_512 The options must be suitable as a value of
633 ipsec_spi(8)'s --ah option. The default is not to use AH. If for
634 some (invalid) reason you still think you need AH, please use esp
635 with the null encryption cipher instead. Note also that not all
636 ciphers available to the kernel (eg through CryptoAPI) are
637 necessarily supported here.
638 fragmentation
640 Whether or not to allow IKE fragmentation. Valid values are yes,
641 (the default), no or force.
642 IKEv1 fragmentation capabilities are negotiated via a well-known
644 private vendor id. IKEv2 fragmentation support is implemented using
645 RFC 7383. If pluto does not receive the fragmentation payload, no
646 IKE fragments will be sent, regardless of the fragmentation=
647 setting. When set to yes, IKE fragmentation will be attempted on
648 the first re-transmit of an IKE packet of a size larger then 576
649 bytes for IPv4 and 1280 bytes for IPv6. If fragmentation is set to
650 force, IKE fragmentation is used on initial transmits of such sized
651 packets as well. When we have received IKE fragments for a
652 connection, pluto behaves as if in force mode.
653 ikepad
655 Whether or not to pad IKEv1 messages to a multiple of 4 bytes.
656 Valid values are yes, (the default) and no.
657 IKE padding is allowed in IKEv1 but has been known to cause
659 interoperability issues. The ikepad= option can be used to disable
660 IKEv1 padding. This used to be required for some devices (such as
661 Checkpoint in Aggressive Mode) that reject padded IKEv1 packets. A
662 bug was fixed in libreswan 3.25 that applied wrong IKE padding in
663 XAUTH, so it is suspected that Checkpoint padding issue bas been
664 resolved. And this option should not be needed by anyone. In IKEv2,
665 no padding is allowed, and this option has no effect. If you find a
666 device that seems to require IKE padding, please contact the
667 libreswan developers. This option should almost never be enabled
668 and might be removed in a future version.
669 ikev2
671 Whether to use IKEv1 (RFC 4301) or IKEv2 (RFC 7296) settings to be
672 used. Currently the accepted values are no(the default), signifying
673 only IKEv1 is accepted, or yes, signifying only IKEv2 is accepted.
674 Previous versions allowed the keywords propose or permit that would
675 allow either IKEv1 or IKEv2, but this is no longer supported. The
676 permit option is interpreted as no and the propose option is
677 interpreted as yes. Older versions also supported keyword insist
678 which is now interpreted as yes.
679 mobike
681 Whether to allow MOBIKE (RFC 4555) to enable a connection to
682 migrate its endpoint without needing to restart the connection from
683 scratch. This is used on mobile devices that switch between wired,
684 wireless or mobile data connections. Current values are no (the
685 default) or yes, Only connection acting as modecfgclient will allow
686 the initiator to migrate using mobike. Only connections acting as
687 modecfgserver will allow clients to migrate.
688 VTI and MOBIKE might not work well when used together.
690 esn
692 Whether or not to enable Extended Sequence Number (ESN) for the
693 IPsec SA. ESN is typically used for very high-speed links (10Gbps
694 or faster) where the standard 32 bit sequence number is exhausted
695 too quickly, causing IPsec SA's rekeys to happen too often.
696 Accepted values are no (the default), yes and either. If either is
697 specified as an initiator, the responder will make the choice. As a
698 responder, if either is received, no is picked.
699 decap-dscp
701 Enable decapsulating the Differentiated Services Code Point (DSCP,
702 formerly known as Terms Of Service (TOS)) bits. If these bits are
703 set on the inner (encrypted) IP packets, these bits are set on the
704 decrypted IP packets. Acceptable values are no (the default) or
705 yes. Currently this feature is only implemented for the Linux
706 XFRM/NETKEY stack.
707 nopmtudisc
709 Disable Path MTU discovery for the IPsec SA. Acceptable values are
710 no (the default) or yes. Currently this feature is only implemented
711 for the Linux XFRM/NETKEY stack.
712 narrowing
714 IKEv2 (RFC5996) Section 2.9 Traffic Selector narrowing options.
715 Currently the accepted values are no, (the default) signifying no
716 narrowing will be proposed or accepted, or yes, signifying IKEv2
717 negotiation may allow establishing an IPsec connection with
718 narrowed down traffic selectors. This option is ignored for IKEv1.
719 There are security implications in allowing narrowing down the
721 proposal. For one, what should be done with packets that we hoped
722 to tunnel, but cannot. Should these be dropped or send in the
723 clear? Second, this could cause thousands of narrowed down Child
724 SAs to be created if the conn has a broad policy (eg 0/0 to 0/0).
725 One possible good use case scenario is that a remote end (that you
726 fully trust) allows you to define a 0/0 to them, while adjusting
727 what traffic you route via them, and what traffic remains outside
728 the tunnel. However, it is always preferred to setup the exact
729 tunnel policy you want, as this will be much clearer to the user.
730 sareftrack
732 Set the method of tracking reply packets with SArefs when using an
733 SAref compatible stack. Currently only the mast stack supports
734 this. Acceptable values are yes (the default), no or conntrack.
735 This option is ignored when SArefs are not supported. This option
736 is passed as PLUTO_SAREF_TRACKING to the updown script which makes
737 the actual decisions whether to perform any iptables/ip_conntrack
738 manipulation. A value of yes means that an IPSEC mangle table will
739 be created. This table will be used to match reply packets. A value
740 of conntrack means that additionally, subsequent packets using this
741 connection will be marked as well, reducing the lookups needed to
742 find the proper SAref by using the ip_conntrack state. A value of
743 no means no IPSEC mangle table is created, and SAref tracking is
744 left to a third-party (kernel) module. In case of a third party
745 module, the SArefs can be relayed using the statsbin= notification
746 helper.
747 nic-offload
749 Set the method of Network Interface Controller (NIC) hardware
750 offload for ESP/AH packet processing. Acceptable values are auto
751 (the default), yes or no. This option is separate from any CPU
752 hardware offload available and is currently only available on Linux
753 4.13+ using the NETKEY/XFRM IPsec stack, when compiled with the
754 options CONFIG_XFRM_OFFLOAD, CONFIG_INET_ESP_OFFLOAD and
755 CONFIG_INET6_ESP_OFFLOAD. The auto option will attempt to
756 auto-detect the presence of kernel and hardware support, and then
757 automatically mark the IPsec SA for hardware offloading. One vendor
758 supporting this offload method is Mellanox.
759 leftid
761 how the left participant should be identified for authentication;
762 defaults to left. Can be an IP address or a fully-qualified domain
763 name which will be resolved. If preceded by @, the value is used as
764 a literal string and will not be resolved. To support opaque
765 identifiers (usually of type ID_KEY_ID, such as used by Cisco to
766 specify Group Name, use square brackets, eg rightid=@[GroupName].
767 The magic value %fromcert causes the ID to be set to a DN taken
768 from a certificate that is loaded. Prior to 2.5.16, this was the
769 default if a certificate was specified. The magic value %none sets
770 the ID to no ID. This is included for completeness, as the ID may
771 have been set in the default conn, and one wishes for it to default
772 instead of being explicitly set. The magic value %myid stands for
773 the current setting of myid. This is set in config setup or by
774 ipsec_whack(8)), or, if not set, it is the IP address in
775 %defaultroute (if that is supported by a TXT record in its reverse
776 domain), or otherwise it is the system's hostname (if that is
777 supported by a TXT record in its forward domain), or otherwise it
778 is undefined.
779 When using certificate based ID's, one need to specify the full
781 RDN, optionally using wildcard matching (eg CN='*'). If the RDN
782 contains a comma, this can be masked using a comma (eg OU='Foo,,
783 Bar and associates')
784 leftrsasigkey
786 the left participant's public key for RSA signature authentication,
787 in RFC 2537 format using ipsec_ttodata(3) encoding. The magic value
788 %none means the same as not specifying a value (useful to override
789 a default). The value %dnsondemand (the default) means the key is
790 to be fetched from DNS at the time it is needed. The value
791 %dnsonload means the key is to be fetched from DNS at the time the
792 connection description is read from ipsec.conf; currently this will
793 be treated as %none if right=%any or right=%opportunistic. The
794 value %dns is currently treated as %dnsonload but will change to
795 %dnsondemand in the future. The identity used for the left
796 participant must be a specific host, not %any or another magic
797 value. The value %cert will load the information required from a
798 certificate defined in %leftcert and automatically define leftid
799 for you. Caution: if two connection descriptions specify different
800 public keys for the same leftid, confusion and madness will ensue.
801 leftcert
803 If you are using leftrsasigkey=%cert this defines the certificate
804 nickname of your certificate in the NSS database. This can be on
805 software or hardware security device.
806 leftckaid
808 The hex CKAID of the X.509 certificate. Certificates are stored in
809 the NSS database.
810 leftauth
812 How the security gateways will authenticate to the other side in
813 the case of asymmetric authentication; acceptable values are rsasig
814 for RSA Authentication with SHA-1, rsa-sha2 for RSA-PSS digital
815 signatures based authentication with SHA2-256, rsa-sha2_384 for
816 RSA-PSS digital signatures based authentication with SHA2-384,
817 rsa-sha2_512 for RSA-PSS digital signatures based authentication
818 with SHA2-512, secret for shared secrets (PSK) authentication and
819 null for null-authentication. There is no default value - if unset,
820 the symmetrical authby= keyword is used to determine the
821 authentication policy of the connection.
822 If asymmetric authentication is requested, IKEv1 must be disabled.
824 If symmetric authentication is required, use authby= instead of
825 leftauth/rightauth. If leftauth is set, rightauth must also be set
826 and authby= must not be set. Asymmetric authentication cannot use
827 secret (psk) on one side and null on the other side - use psk on
828 both ends instead.
829 Be aware that the symmetric keyword is authby= but the asymmetric
831 keyword is leftauth and rightauth (without the "by").
832 leftca
834 specifies the authorized Certificate Authority (CA) that signed the
835 certificate of the peer. If undefined, it defaults to the CA that
836 signed the certificate specified in leftcert. The special
837 rightca=%same is implied when not specifying a rightca and means
838 that only peers with certificates signed by the same CA as the
839 leftca will be allowed. This option is only useful in complex multi
840 CA certificate situations. When using a single CA, it can be safely
841 omitted for both left and right.
842 leftikeport
844 The UDP IKE port to listen on or send data to. This port cannot be
845 0 or 500. For TCP, see tcp-remoteport=
846 leftsendcert
848 This option configures when Libreswan will send X.509 certificates
849 to the remote host. Acceptable values are yes|always (signifying
850 that we should always send a certificate), sendifasked (signifying
851 that we should send a certificate if the remote end asks for it),
852 and no|never (signifying that we will never send a X.509
853 certificate). The default for this option is sendifasked which may
854 break compatibility with other vendor's IPsec implementations, such
855 as Cisco and SafeNet. If you find that you are getting errors about
856 no ID/Key found, you likely need to set this to always. This
857 per-conn option replaces the obsolete global nocrsend option.
858 leftxauthserver
860 Left is an XAUTH server. This can use PAM for authentication or md5
861 passwords in /etc/ipsec.d/passwd. These are additional credentials
862 to verify the user identity, and should not be confused with the
863 XAUTH group secret, which is just a regular PSK defined in
864 ipsec.secrets. The other side of the connection should be
865 configured as rightxauthclient. XAUTH connections cannot rekey, so
866 rekey=no should be specified in this conn. For further details on
867 how to compile and use XAUTH, see README.XAUTH. Acceptable values
868 are yes or no (the default).
869 leftxauthclient
871 Left is an XAUTH client. The xauth connection will have to be
872 started interactively and cannot be configured using auto=start.
873 Instead, it has to be started from the commandline using ipsec auto
874 --up connname. You will then be prompted for the username and
875 password. To setup an XAUTH connection non-interactively, which
876 defeats the whole purpose of XAUTH, but is regularly requested by
877 users, it is possible to use a whack command - ipsec whack --name
878 baduser --ipsecgroup-xauth --xauthname badusername --xauthpass
879 password --initiate The other side of the connection should be
880 configured as rightxauthserver. Acceptable values are yes or no
881 (the default).
882 leftusername
884 The username associated with this connection. The username can be
885 the IKEv2 XAUTH username, a GSSAPI username or IKEv2 CP username.
886 For the XAUTH username, the XAUTH password can be configured in the
887 ipsec.secrets file. This option was previously called
888 leftxauthusername.
889 leftmodecfgserver
891 Left is a Mode Config server. It can push network configuration to
892 the client. Acceptable values are yes or no (the default).
893 leftmodecfgclient
895 Left is a Mode Config client. It can receive network configuration
896 from the server. Acceptable values are yes or no (the default).
897 xauthby
899 When IKEv1 XAUTH support is available, set the method used by XAUTH
900 to authenticate the user with IKEv1. The currently supported values
901 are file (the default), pam or alwaysok. The password file is
902 located at /etc/ipsec.d/passwd, and follows a syntax similar to the
903 Apache htpasswd file, except an additional connection name argument
904 (and optional static IP address) are also present:
905 username:password:conname:ipaddress
907 For supported password hashing methods, see crypt(3). If pluto is
909 running in FIPS mode, some hash methods, such as MD5, might not be
910 available. Threads are used to launch an xauth authentication
911 helper for file as well as PAM methods.
912 The alwaysok should only be used if the XAUTH user authentication
914 is not really used, but is required for interoperability, as it
915 defeats the whole point of XAUTH which is to rely on a secret only
916 known by a human. See also pam-authorize=yes
917 xauthfail
919 When XAUTH support is available, set the failure method desired
920 when authentication has failed. The currently supported values are
921 hard (the default) and soft. A soft failure means the IPsec SA is
922 allowed to be established, as if authentication had passed
923 successfully, but the XAUTH_FAILED environment variable will be set
924 to 1 for the updown script, which can then be used to redirect the
925 user into a walled garden, for example a payment portal.
926 pam-authorize
928 IKEv1 supports PAM authorization via XAUTH using xauthby=pam. IKEv2
929 does not support receiving a plaintext username and password.
930 Libreswan does not yet support EAP authentication methods for IKE.
931 The pam-authorize=yes option performs an authorization call via
932 PAM, but only includes the remote ID (not username or password).
933 This allows for backends to disallow an ID based on non-password
934 situations, such as "user disabled" or "user over quota". See also
935 xauthby=pam
936 modecfgpull
938 Pull the Mode Config network information from the server.
939 Acceptable values are yes or no (the default).
940 modecfgdns, modecfgdomains, modecfgbanner
942 When configured as IKEv1 ModeCFG or IKEv2 server, specifying any of
943 these options will cause those options and values to be sent to the
944 connecting client. Libreswan as a client will use these received
945 options to either update /etc/resolv.conf or the running unbound
946 DNS server. When the connection is brought down, the previous DNS
947 resolving state is restored.
948 The modecfgdns option takes a comma or space separated list of IP
950 addresses that can be used for DNS resolution. The modecfgdomains
951 option takes a comma or space separated list of internal domain
952 names that are reachable via the supplied modecfgdns DNS servers.
953 The IKEv1 split tunnel directive will be sent automatically if the
955 xauth server side has configured a network other than 0.0.0.0/0.
956 For IKEv2, this is automated via narrowing.
957 remote-peer-type
959 Set the remote peer type. This can enable additional processing
960 during the IKE negotiation. Acceptable values are cisco or ietf
961 (the default). When set to cisco, support for Cisco IPsec gateway
962 redirection and Cisco obtained DNS and domainname are enabled. This
963 includes automatically updating (and restoring) /etc/resolv.conf.
964 These options require that XAUTH is also enabled on this
965 connection.
966 nm-configured
968 Mark this connection as controlled by Network Manager. Acceptable
969 values are yes or no (the default). Currently, setting this to yes
970 will cause libreswan to skip reconfiguring resolv.conf when used
971 with XAUTH and ModeConfig.
972 encapsulation
974 In some cases, for example when ESP packets are filtered or when a
975 broken IPsec peer does not properly recognise NAT, it can be useful
976 to force RFC-3948 encapsulation. In other cases, where IKE is
977 NAT'ed but ESP packets can or should flow without encapsulation, it
978 can be useful to ignore the NAT-Traversal auto-detection.
979 encapsulation=yes forces the NAT detection code to lie and tell the
980 remote peer that RFC-3948 encapsulation (ESP in port 4500 packets)
981 is required. encapsulation=no ignores the NAT detection causing
982 ESP packets to send send without encapsulation. The default value
983 of encapsulation=auto follows the regular outcome of the NAT
984 auto-detection code performed in IKE. This option replaced the
985 obsoleted forceencaps option.
986 enable-tcp
988 Normally, IKE negotiation and ESP encapsulation happens over UDP.
989 This option enables support for IKE and ESP over TCP as per RFC
990 8229. Acceptable values are no(the default), yes meaning only TCP
991 will be used, or fallback meaning that TCP will be attempted only
992 after negotiation over UDP failed. Since performance over TCP is
993 much less, and TCP sessions are vulnerable to simply RST resets and
994 MITM attacks causing the TCP connection to close, this option
995 should really only be used in fallback mode. If used in fallback
996 mode, it is recommend to reduce the retransmit-timeout from the
997 default 60s to a much shorter value such as 10s, so that one does
998 not have to wait a minute for the TCP fallback to be attempted.
999 tcp-remoteport
1001 Which remote TCP port to use when IKE over TCP is attempted. The
1002 default value is to use the NAT-T IKE port (4500). This value is
1003 not negotiated and should be configured properly on all endpoints.
1004 When opening a TCP socket to the remote host in this port, a
1005 regular ephemeral source port is obtained from the OS. For changing
1006 the UDP ports, see leftikeport=
1007 nat-keepalive
1009 whether to send any NAT-T keep-alives. These one byte packets are
1010 send to prevent the NAT router from closing its port when there is
1011 not enough traffic on the IPsec connection. Acceptable values are:
1012 yes (the default) and no.
1013 initial-contact
1015 whether to send an INITIAL_CONTACT payload to the peer we are
1016 initiating to, if we currently have no IPsec SAs up with that peer.
1017 Acceptable values are: no (the default) and yes. It is recommended
1018 to leave this option unset, unless the remote peer requires it to
1019 allow reconnects. The only known peer at this time is Cisco, which
1020 will not allow a reconnect (despite authentication) to replace an
1021 existing IPsec SA unless it receives an INITIAL_CONTACT payload.
1022 Receiving this payload is ignored and the choice to replace or add
1023 an IPsec SA when libreswan is a responder is purely based on the
1024 uniqueids setting, which should be left enabled unless libreswan
1025 acts as an XAUTH server using PSK ("group secret"). This option can
1026 cause a few seconds of downtime on the IPsec tunnel between the
1027 time the remote clears the old IPsec SA in response to our
1028 INITIAL_CONTACT message, and the time we finish setting up the new
1029 IPsec SA. If there is an XAUTH step in between, and especially when
1030 XAUTH requires the use of some two-factor token, this downtime
1031 could be even longer.
1032 cisco-unity
1034 whether to send a CISCO_UNITY payload to the peer. Acceptable
1035 values are: no (the default) and yes. It is recommended to leave
1036 this option unset, unless the remote peer (Cisco client or server)
1037 requires it. This option does not modify local behaviour. It can be
1038 needed to connect as a client to a Cisco server. It can also be
1039 needed to act as a server for a Cisco client, which otherwise might
1040 send back an error DEL_REASON_NON_UNITY_PEER.
1041 ignore-peer-dns
1043 whether to ignore received DNS configuration. Acceptable values
1044 are: no (the default) and yes. Normally, when a roadwarrior
1045 connects to a remote VPN, the remote VPN server sends a list of DNS
1046 domains and DNS nameserver IP addresses that the roadwarrior can
1047 use to reach internal only resources through the VPN. This option
1048 allows the roadwarrior to ignore the server's suggestion. The
1049 roadwarrior will normally use this information to update the DNS
1050 resolving process. What is changed depends on the detected DNS
1051 configuration. It can modify /etc/resolv.conf directly, or
1052 reconfigure a locally running DNS server (unbound, knot, stubby or
1053 systemd-resolved) or inform NetworkManager.
1054 accept-redirect
1056 Whether requests of the remote peer to redirect IKE/IPsec SA's are
1057 accepted. Valid options are no (the default) and yes. See also
1058 accept-redirect-to.
1059 accept-redirect-to
1061 Specify the comma separated list of addresses we accept being
1062 redirected to. Both IPv4 and IPv6 addresses are supported as well
1063 the FQDNs. The value %any, as well as not specifying any address,
1064 signifes that we will redirect to any address gateway sends us in
1065 REDIRECT notify payload.
1066 The value of this option is not considered at all if
1068 accept-redirect is set to no.
1069 send-redirect
1071 Whether to send requests for the remote peer to redirect IKE/IPsec
1072 SA's during IKE_AUTH. Valid options are no (the default) and yes.
1073 If set, the option redirect-to= must also be set to indicate where
1074 to redirect peers to. For redirection during IKE_SA_INIT exchange,
1075 see the global-redirect= and global-redirect-to= options. Runtime
1076 redirects can be triggered via the ipsec whack --redirect command.
1077 redirect-to
1079 Where to send remote peers to via the send-redirect option. This
1080 can be an IP address or hostname (FQDN).
1081 fake-strongswan
1083 whether to send a STRONGSWAN Vendor ID payload to the peer.
1084 Acceptable values are: no (the default) and yes. This used to be
1085 required because strongswan rejects certain proposals with private
1086 use numbers such as esp=twofish or esp=serpent unless it receives a
1087 strongswan vendorid by the peer. This option sends such an
1088 (unversioned) vendor id. Note that libreswan and strongswan no
1089 longer support twofish or serpent, so enabling this option likely
1090 will no longer do anything.
1091 send-vendorid
1093 whether to send our Vendor ID during IKE. Acceptable values are: no
1094 (the default) and yes. The vendor id sent can be configured using
1095 the "config setup" option myvendorid=. It defaults to
1096 OE-Libreswan-VERSION.
1097 Vendor ID's can be useful in tracking interoperability problems.
1099 However, specific vendor identification and software versions can
1100 be useful to an attacker when there are known vulnerabilities to a
1101 specific vendor/version.
1102 The prefix OE stands for "Opportunistic Encryption". This prefix
1104 was historically used by The FreeS/WAN Project and The Openswan
1105 Project (openswan up to version 2.6.38) and in one Xeleranized
1106 openswan versions (2.6.39). Further Xeleranized openswan's use the
1107 prefix OSW.
1108 overlapip
1110 a boolean (yes/no) that determines, when (left|right)subnet=vhost:
1111 is used, if the virtual IP claimed by this states created from this
1112 connection can with states created from other connections.
1113 Note that connection instances created by the Opportunistic
1115 Encryption or PKIX (x.509) instantiation system are distinct
1116 internally. They will inherit this policy bit.
1117 The default is no.
1119 This feature is only available with kernel drivers that support SAs
1121 to overlapping conns. At present only the (klips) mast protocol
1122 stack supports this feature.
1123 reqid
1125 a unique identifier used to match IPsec SAs using iptables with
1126 NETKEY/XFRM. This identifier is normally automatically allocated in
1127 groups of 4. It is exported to the _updown script as REQID. On
1128 Linux, reqids are supported with IP Connection Tracking and NAT
1129 (iptables). Automatically generated values use the range 16380 and
1130 higher. Manually specified reqid values therefore must be between 1
1131 and 16379.
1132 Automatically generated reqids use a range of 0-3 (eg 16380-16383
1134 for the first reqid). These are used depending on the exact policy
1135 (AH, AH+ESP, IPCOMP, etc).
1136 WARNING: Manually assigned reqids are all identical. Instantiations
1138 of connections (those using %any wildcards) will all use the same
1139 reqid. If you use manual assigning you should make sure your
1140 connections only match single road warrior only or you break
1141 multiple road warriors behind same NAT router because this feature
1142 requires unique reqids to work.
1143 For KLIPS, when using the MAST variant, a different mechanism
1145 called SAref is in use. See overlapip and sareftrack.
1146 dpddelay
1148 Set the delay (in time units, defaults to seconds) between Dead
1149 Peer Detection (IKEv1 RFC 3706) or IKEv2 Liveness keepalives that
1150 are sent for this connection (default 0 seconds). Set to enable
1151 checking. If dpddelay is set, dpdtimeout also needs to be set.
1152 dpdtimeout
1154 Set the length of time (in time units, defaults to seconds) that we
1155 will idle without hearing back from our peer. After this period has
1156 elapsed with no response and no traffic, we will declare the peer
1157 dead, and remove the SA (default 0 seconds). Set value bigger than
1158 dpddelay to enable. If dpdtimeout is set, dpddelay also needs to be
1159 set.
1160 dpdaction
1162 When a DPD enabled peer is declared dead, what action should be
1163 taken. hold (default) means the eroute will be put into %hold
1164 status, while clear means the eroute and SA with both be cleared.
1165 restart means that ALL SAs to the dead peer will renegotiated.
1166 dpdaction=clear is really only useful on the server of a Road
1168 Warrior config.
1169 The value restart_by_peer has been obsoleted and its functionality
1171 moved into the regular restart action.
1172 pfs
1174 whether Perfect Forward Secrecy of keys is desired on the
1175 connection's keying channel (with PFS, penetration of the
1176 key-exchange protocol does not compromise keys negotiated earlier);
1177 Acceptable values are yes (the default) and no.
1178 pfsgroup
1180 This option is obsoleted, please use phase2alg if you need the PFS
1181 to be different from phase1 (the default) using:
1182 phase2alg=aes128-md5;modp1024
1183 aggressive
1185 Use IKEv1 Aggressive Mode instead of IKEv1 Main Mode. This option
1186 has no effect when IKEv2 is used. Acceptable values are no (the
1187 default) or yes. When this option is enabled, IKEv1 Main Mode will
1188 no longer be allowed for this connection. The old name of this
1189 option was aggrmode.
1190 Aggressive Mode is less secure, and more vulnerable to Denial Of
1192 Service attacks. It is also vulnerable to brute force attacks with
1193 software such as ikecrack. It should not be used, and it should
1194 especially not be used with XAUTH and group secrets (PSK). If the
1195 remote system administrator insists on staying irresponsible,
1196 enable this option.
1197 Aggressive Mode is further limited to only proposals with one DH
1199 group as there is no room to negotiate the DH group. Therefore it
1200 is mandatory for Aggressive Mode connections that both ike= and
1201 phase2alg= options are specified with only one fully specified
1202 proposal using one DH group.
1203 The KE payload is created in the first exchange packet when using
1205 aggressive mode. The KE payload depends on the DH group used. This
1206 is why there cannot be multiple DH groups in IKEv1 aggressive mode.
1207 In IKEv2, which uses a similar method to IKEv1 Aggressive Mode,
1208 there is an INVALID_KE response payload that can inform the
1209 initiator of the responder's desired DH group and so an IKEv2
1210 connection can actually recover from picking the wrong DH group by
1211 restarting its negotiation.
1212 salifetime
1214 how long a particular instance of a connection (a set of
1215 encryption/authentication keys for user packets) should last, from
1216 successful negotiation to expiry; acceptable values are an integer
1217 optionally followed by s (a time in seconds) or a decimal number
1218 followed by m, h, or d (a time in minutes, hours, or days
1219 respectively) (default 8h, maximum 24h). Normally, the connection
1220 is renegotiated (via the keying channel) before it expires. The two
1221 ends need not exactly agree on salifetime, although if they do not,
1222 there will be some clutter of superseded connections on the end
1223 which thinks the lifetime is longer.
1224 The keywords "keylife" and "lifetime" are obsoleted aliases for
1226 "salifetime." Change your configs to use "salifetime" instead.
1227 replay-window
1229 The size of the IPsec SA replay window protection. The default is
1230 kernel stack specific, but usually 32. Linux NETKEY/XFRM allows at
1231 least up to 2048. A value of of 0 disables replay protection.
1232 Disabling of replay protection is sometimes used on a pair of IPsec
1233 servers in a High Availability setup, or on servers with very
1234 unpredictable latency, such as mobile networks, which can cause an
1235 excessive amount of out of order packets. Sequence errors can be
1236 seen in /proc/net/xfrm_stat. Note that technically, at least the
1237 Linux kernel can install IPsec SA's with an IPsec SA Sequence
1238 Number, but this is currently not supported by libreswan.
1239 rekey
1241 whether a connection should be renegotiated when it is about to
1242 expire; acceptable values are yes (the default) and no. The two
1243 ends need not agree, but while a value of no prevents Pluto from
1244 requesting renegotiation, it does not prevent responding to
1245 renegotiation requested from the other end, so no will be largely
1246 ineffective unless both ends agree on it.
1247 rekeymargin
1249 how long before connection expiry or keying-channel expiry should
1250 attempts to negotiate a replacement begin; acceptable values as for
1251 salifetime (default 9m). Relevant only locally, other end need not
1252 agree on it.
1253 rekeyfuzz
1255 maximum percentage by which rekeymargin should be randomly
1256 increased to randomize rekeying intervals (important for hosts with
1257 many connections); acceptable values are an integer, which may
1258 exceed 100, followed by a `%' (default set by ipsec_pluto(8),
1259 currently 100%). The value of rekeymargin, after this random
1260 increase, must not exceed salifetime. The value 0% will suppress
1261 time randomization. Relevant only locally, other end need not agree
1262 on it.
1263 keyingtries
1265 how many attempts (a whole number or %forever) should be made to
1266 negotiate a connection, or a replacement for one, before giving up
1267 (default %forever). The value %forever or 0 means to keep trying
1268 forever. For Opportunistic Encryption connections, a keyingtries
1269 value of %forever or 0 is set to 1 and a warning message will be
1270 logged. This is because an expired failureshunt triggers new
1271 keyingtries on-demand later, when there is traffic. This prevents
1272 accumulating an infinite amount of attempts to peers that do not
1273 support Opportunistic Encryption. For Opportunistic, a keyingtries
1274 value of > 1 is allowed but currently not recommended. The meaning
1275 of failureshunt= is unclear when there is continued (failed) keying
1276 happening with a negotiationshunt installed. Relevant only locally,
1277 other end need not agree on it.
1278 ikelifetime
1280 how long the keying channel of a connection (buzzphrase: “IKE SA”
1281 or “Parent SA”) should last before being renegotiated; acceptable
1282 values as for salifetime. The default as of version 4.2 is 8h,
1283 before that it was 1h. The maximum is 24h. The two-ends-disagree
1284 case is similar to that of salifetime.
1285 retransmit-timeout
1287 how long a single packet, including retransmits of that packet, may
1288 take before the IKE attempt is aborted. If rekeying is enabled, a
1289 new IKE attempt is started. The default set by ipsec_pluto(8),
1290 currently is 60s. See also: retransmit-interval, rekey and
1291 keyingtries.
1292 retransmit-interval
1294 the initial interval time period, specified in msecs, that pluto
1295 waits before retransmitting an IKE packet. This interval is doubled
1296 for each attempt (exponential back-off). The default set by
1297 ipsec_pluto(8), currently is 500. See also: retransmit-timeout,
1298 rekey and keyingtries.
1299 compress
1301 whether IPComp compression of content is proposed on the connection
1302 (link-level compression does not work on encrypted data, so to be
1303 effective, compression must be done before encryption); acceptable
1304 values are yes and no (the default).
1305 For IKEv1, compress settings on both peers must match. For IKEv2,
1307 compression can only be suggested and a mismatched compress setting
1308 results in connection without compression.
1309 When set to yes, compression is negotiated for the DEFLATE
1311 compression algorithm.
1312 metric
1314 Set the metric for added routes. This value is passed to the
1315 _updown scripts as PLUTO_METRIC. Acceptable values are positive
1316 numbers, with the default being 1.
1317 mtu
1319 Set the MTU for the route(s) to the remote endpoint and/or subnets.
1320 This is sometimes required when the overhead of the IPsec
1321 encapsulation would cause the packet the become too big for a
1322 router on the path. Since IPsec cannot trust any unauthenticated
1323 ICMP messages, PATH MTU discovery does not work. This can also be
1324 needed when using "6to4" IPV6 deployments, which adds another
1325 header on the packet size. Acceptable values are positive numbers.
1326 There is no default.
1327 tfc
1329 Enable Traffic Flow Confidentiality ("TFC") (RFC-4303) for outgoing
1330 ESP packets in Tunnel Mode. When enabled, ESP packets are padded to
1331 the specified size (up to the PMTU size) to prevent leaking
1332 information based on ESP packet size. This option is ignored for AH
1333 and for ESP in Transport Mode as those always leak traffic
1334 characteristics and applying TFC will not do anything. Acceptable
1335 values are positive numbers. The value 0 means TFC padding is not
1336 performed. Currently this feature is only implemented for the Linux
1337 XFRM/NETKEY stack. In IKEv2, when the notify payload
1338 ESP_TFC_PADDING_NOT_SUPPORTED is received, TFC padding is disabled.
1339 The default is not to do any TFC padding, but this might change in
1340 the near future.
1341 send-no-esp-tfc
1343 Whether or not to tell the remote peer that we do not support
1344 Traffic Flow Confidentiality ("TFC") (RFC-4303). Possible values
1345 are no (the default) which allows the peer to use TFC or yes which
1346 prevents to peer from using TFC. This does not affect whether this
1347 endpoint uses TFC, which only depends on the local tfc setting.
1348 This option is only valid for IKEv2.
1349 nflog
1351 If set, the NFLOG group number to log this connection's pre-crypt
1352 and post-decrypt traffic to. The default value of 0 means no
1353 logging at all. This option is only available on linux kernel
1354 2.6.14 and later. It allows common network utilities such as
1355 tcpdump, wireshark and dumpcap, to use nflog:XXX pseudo interfaces
1356 where XXX is the nflog group number. During the updown phase of a
1357 connection, iptables will be used to add and remove the
1358 source/destination pair to the nflog group specified. The rules are
1359 setup with the nflog-prefix matching the connection name. See also
1360 the global nflog-all option.
1361 mark
1363 If set, the MARK to set for the IPsec SA of this connection. The
1364 format of a CONNMARK is mark/mask. If the mask is left out, a
1365 default mask of 0xffffffff is used. A mark value of -1 means to
1366 assign a new global unique mark number for each instance of the
1367 connection. Global marks start at 1001. This option is only
1368 available on linux NETKEY/XFRM kernels. It can be used with
1369 iptables to create custom iptables rules using CONNMARK. It can
1370 also be used with Virtual Tunnel Interfaces ("VTI") to direct
1371 marked traffic to specific vtiXX devices.
1372 mark-in
1374 The same as mark, but mark-in only applies to the inbound half of
1375 the IPsec SA. It overrides any mark= setting.
1376 mark-out
1378 The same as mark, but mark-out only applies to the outbound half of
1379 the IPsec SA. It overrides any mark= setting.
1380 vti-interface
1382 This option is used to create "Routing based VPNs" (as opposed to
1383 "Policy based VPNs"). It will create a new interface that can be
1384 used to route traffic in for encryption/decryption. The Virtual
1385 Tunnel Interface ("VTI") interface name is used to for all IPsec
1386 SA's created by this connection. This requires that the connection
1387 also enables either the mark= or mark-in= / mark-out- option(s).
1388 All traffic marked with the proper MARKs will be automatically
1389 encrypted if there is an IPsec SA policy covering the
1390 source/destination traffic. Tools such as tcpdump and iptables can
1391 be used on all cleartext pre-encrypt and post-decrypt traffic on
1392 the device. See the libreswan wiki for example configurations that
1393 use VTI.
1394 VTI interfaces are currently only supported on Linux with
1396 XFRM/NETKEY. The _updown script handles certain Linux specific
1397 interfaces settings required for proper functioning
1398 (disable_policy, rp_filter, forwarding, etc). Interface names are
1399 limited to 16 characters and may not allow all characters to be
1400 used. If marking and vti-routing=yes is used, no manual iptables
1401 should be required. However, administrators can use the iptables
1402 mangle table to mark traffic manually if desired.
1403 vti-routing
1405 Whether or not to add network rules or routes for IPsec SA's to the
1406 respective VTI devices. Valid values are yes (the default) or no.
1407 When using "routing based VPNs" with a subnets policy of 0.0.0.0/0,
1408 this setting needs to set to no to prevent imploding the tunnel,
1409 and the administrator is expected to manually add ip rules and ip
1410 routes to configure what traffic must be encrypted. When set to
1411 yes, the _updown script will automatically route the
1412 leftsubnet/rightsubnet traffic into the VTI device specified with
1413 vti-interface
1414 vti-shared
1416 Whether or not the VTI device is shared amongst connections. Valid
1417 values are no (the default) or yes. When set to no, the VTI device
1418 is automatically deleted if the connection is a single
1419 non-instantiated connection. If a connection instantiates (eg
1420 right=%any) then this option has no effect, as the VTI device is
1421 not removed as it is shared with multiple roadwarriors.
1422 ipsec-interface
1424 Create or use an existing virtual interface ipsecXXX for "Routing
1425 based VPNs" (as opposed to "Policy based VPNs"). Valid options are
1426 yes, no or a number. When using a number, the IPsec interface
1427 created and/or used will use that number as part of the interface
1428 name. For example setting ipsec-interface=5 will create and/or use
1429 the ipsec5 interface. The value 0 cannot be used and is interpreted
1430 as no. The value yes is interpreted as the number 1, and thus will
1431 use the interface named ipsec1. An IP address can be configured for
1432 this interface via the interface-ip= option.
1433 The ipsec-interface is used to route outbound traffic that needs to
1435 be encrypted, and will decrypt inbound traffic that arrives on this
1436 interface. All traffic that is routed to this interface will be
1437 automatically encrypted providing the IPsec SA policy covers this
1438 traffic. Traffic not matching the IPsec SA will be dropped. Tools
1439 such as tcpdump, iptables, ifconfig and tools that need traffic
1440 counters can be used on all cleartext pre-encrypt and post-decrypt
1441 traffic on the device. When leftsubnet= is equal to rightsubnet=,
1442 the routing needs to be manged by an external routing daemon or
1443 manually by the administrator.
1444 This option is currently only supported on Linux kernels 4.19 or
1446 later when compiled with XFRMi support (CONFIG_XFRM_INTERFACE). The
1447 number of the ipsecX device corresponds with the XFRM IF_ID policy
1448 option of the IPsec SA in the Linux kernel. On Linux, XFRMi
1449 interfaces can be managed by libreswan automatically or can be
1450 preconfigured on the system using the existing init system or via
1451 networking tools such as systemd-networkd and NetworkManager. The
1452 _updown script handles certain Linux specific interfaces settings
1453 required for proper functioning, such as forwarding and routing
1454 rules for IPsec traffic.
1455 The ipsec-interface=0 will create an interface with the same name
1457 as the old KLIPS interface, ipsec0. This interface name should only
1458 be used when required for migration from KLIPS to XFRM interfaces.
1459 Since XFRM IF_ID and marking cannot use 0, this is mapped to 16384.
1460 This means that the devices ipsec0 and ipsec16384 cannot both be in
1461 use.
1462 interface-ip=
1464 The IP address and netmask to configure on a virtual device (eg
1465 ipsecXXX). This is often used when building Routing based IPsec
1466 tunnels using transport mode and GRE, but can also be useful in
1467 other scenarios. Currently requires ipsec-interface=. See also
1468 leftvti= for cnofiguring IP addresses when using VTI.
1469 priority
1471 The priority in the kernel SPD/SAD database, when matching up
1472 packets. Each kernel (NETKEY, KLIPS, OSX, etc) has its own
1473 mechanism for setting the priority. Setting this option to non-zero
1474 passes the priority to the kernel stack unmodified. The maximum
1475 value depends on the stack. It is recommended not to exceed 65536
1476 KLIPS and NETKEY use a priority system based on "most specific
1478 match first". It uses an internal algorithm to calculate these
1479 based on network prefix length, protocol and port selectors. A
1480 lower value means a higher priority.
1481 Typical values are about the 2000 range. These can be seen on the
1483 NETKEY stack using ip xfrm policy when the connection is up. For
1484 "anonymous IPsec" or Opportunistic Encryption based connections, a
1485 much lower priority (65535) is used to ensure administrator
1486 configured IPsec always takes precedence over opportunistic IPsec.
1487 sendca
1489 How much of our available X.509 trust chain to send with the End
1490 certificate, excluding any root CA's. Specifying issuer sends just
1491 the issuing intermediate CA, while
1492 all will send the entire chain of intermediate CA's.none (the
1493 default) will not send any CA certs.
1494 labeled-ipsec
1496 This option is obsolete. To enable labeled IPsec, setting the
1497 policy-label= is enough. See also policy-label= and
1498 secctx-attr-type=
1499 policy-label
1501 The string representation of an access control security label that
1502 is interpreted by the LSM (e.g. SELinux) for use with Labeled
1503 IPsec. See also labeled-ipsec= and secctx-attr-type=. For example,
1504 policy-label=system_u:object_r:ipsec_spd_t:s0-s15:c0.c1023
1505 failureshunt
1507 what to do with packets when negotiation fails. The default is
1508 none: no shunt; passthrough, drop, and reject have the obvious
1509 meanings.
1510 negotiationshunt
1512 What to do with packets during the IKE negotiation. Valid options
1513 are hold (the default) or passthrough. This should almost always be
1514 left to the default hold value to avoid cleartext packet leaking.
1515 The only reason to set this to passthrough is if plaintext service
1516 availability is more important than service security or privacy, a
1517 scenario that also implies failureshunt=passthrough and most likely
1518 authby=%null using Opportunistic Encryption.
1519
1521 At present, the only config section known to the IPsec software is the
1522 one named setup, which contains information used when the software is
1523 being started (see ipsec_setup(8)). Here's an example:
1524 config setup
1527 logfile=/var/log/pluto.log
1528 plutodebug=all
1529 Parameters are optional unless marked “(required)”.
1531 The currently-accepted parameter names in a config setup section are:
1533 protostack
1535 decide which protocol stack is going to be used. Valid values are
1536 "xfrm" and "bsd". This option should no longer be set, as the stack
1537 is currently auto-detected. The values "klips, "mast", "netkey",
1538 "native", "kame" and "auto" are obsolete. The option is kept only
1539 because it is suspected that Linux and BSD will get userspace
1540 stacks with IPsec support soon (such as dpdk).
1541 interfaces
1543 virtual and physical interfaces for IPsec to use: a single
1544 virtual=physical pair, a (quoted!) list of pairs separated by white
1545 space, or %none. One of the pairs may be written as %defaultroute,
1546 which means: find the interface d that the default route points to,
1547 and then act as if the value was ``ipsec0=d''. %defaultroute is
1548 the default; %none must be used to denote no interfaces, or when
1549 using the NETKEY stack. If %defaultroute is used (implicitly or
1550 explicitly) information about the default route and its interface
1551 is noted for use by ipsec_auto(8).)
1552 listen
1554 IP address to listen on (default depends on interfaces= setting).
1555 Currently only accepts one IP address.
1556 ike-socket-bufsize
1558 Set the IKE socket buffer size. Default size is determined by the
1559 OS (as of writing, this seems to be set to 212992. On Linux this is
1560 visible via /proc/sys/net/core/rmem_default and
1561 /proc/sys/net/core/wmem_default. On Linux, this option uses
1562 SO_RCVBUFFORCE and SO_SNDBUFFORCE so that it can override
1563 rmem_max/wmem_max values of the OS. This requires CAP_NET_ADMIN
1564 (which is also required for other tasks). This option can also be
1565 toggled on a running system using ipsec whack --ike-socket-bufsize
1566 bufsize.
1567 ike-socket-errqueue
1569 Whether to enable or disable receiving socket errors via
1570 IP_RECVERR. The default is enabled. This will cause the socket to
1571 receive, process and log socket errors, such as ICMP unreachable
1572 messages or Connection Refused messages. Disabling this only makes
1573 sense on very busy servers, and even then it might not make much of
1574 a difference. This option can also be toggled on a running system
1575 using ipsec whack --ike-socket-errqueue-toggle.
1576 listen-udp
1578 Whether the pluto IKE daemon should listen on the standard UDP
1579 ports of 500 and 4500. The value "yes" means to listen on these
1580 ports, and is the default. This should almost never be disabled. In
1581 the rare case where it is known that only ever TCP or non-standard
1582 UDP ports will be used, this option can disable the standard UDP
1583 ports. Connections can specify their own non-standard port using
1584 leftikeport=.
1585 listen-tcp
1587 Whether the pluto IKE daemon should listen on the (pseudo) standard
1588 TCP port 4500. The value "no" is the current default, but this will
1589 be changed in the future to "yes". The TCP usage complies to RFC
1590 8229 for IKE and ESP over TCP support. Connections can specify
1591 their own non-standard port using leftikeport=.
1592 nflog-all
1594 If set, the NFLOG group number to log all pre-crypt and
1595 post-decrypt traffic to. The default value of 0 means no logging at
1596 all. This option is only available on linux kernel 2.6.14 and
1597 later. It allows common network utilities such as tcpdump,
1598 wireshark and dumpcap, to use nflog:XXX pseudo interfaces where XXX
1599 is the nflog group number. During startup and shutdown of the IPsec
1600 service, iptables commands will be used to add or remove the global
1601 NFLOG table rules. The rules are setup with the nflog-prefix
1602 all-ipsec. See also the per-connection nflog option.
1603 keep-alive
1605 The delay (in seconds) for NAT-T keep-alive packets, if these are
1606 enabled using nat-keepalive This parameter may eventually become
1607 per-connection.
1608 virtual-private
1610 contains the networks that are allowed as (left|right)subnet= for
1611 the remote clients when using the vhost: or vnet: keywords in the
1612 (left|right)subnet= parameters. In other words, the address ranges
1613 that may live behind a NAT router through which a client connects.
1614 This value is usually set to all the RFC-1918 address space,
1615 excluding the space used in the local subnet behind the NAT (An IP
1616 address cannot live at two places at once). IPv4 address ranges are
1617 denoted as %v4:a.b.c.d/mm and IPv6 is denoted as
1618 %v6:aaaa::bbbb:cccc:dddd:eeee/mm. One can exclude subnets by using
1619 the !. For example, if the VPN server is giving access to
1620 192.168.1.0/24, this option should be set to:
1621 virtual-private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:!192.168.1.0/24.
1622 This parameter is only needed on the server side and not on the
1623 client side that resides behind the NAT router, as the client will
1624 just use its IP address for the inner IP setting. This parameter
1625 may eventually become per-connection. See also leftsubnet=
1626 Note: It seems that T-Mobile in the US and Rogers/Fido in Canada
1628 have started using 25.0.0.0/8 as their pre-NAT range. This range
1629 technically belongs to the Defence Interoperable Network Services
1630 Authority (DINSA), an agency of the Ministry of Defence of the
1631 United Kingdom. The network range seems to not have been announced
1632 for decades, which is probably why these organisations "borrowed"
1633 this range. To support roadwarriors on these 3G networks, you might
1634 have to add it to the virtual-private= line.
1635 myvendorid
1637 The string to use as our vendor id (VID) when send-vendorid=yes.
1638 The default is OE-Libreswan-VERSION.
1639 nhelpers
1641 how many pluto helpers are started to help with cryptographic
1642 operations. Pluto will start as many helpers as the number of
1643 CPU's, minus 1 to dedicate to the main thread. For machines with
1644 less than 4 CPU's, an equal number of helpers to CPU's are started.
1645 A value of 0 forces pluto to do all operations inline using the
1646 main process. A value of -1 tells pluto to perform the above
1647 calculation. Any other value forces the number to that amount.
1648 seedbits
1650 Pluto uses the NSS crypto library as its random source. Some
1651 government Three Letter Agencies require that pluto reads
1652 additional bits from /dev/random and feed these into the NSS RNG
1653 before drawing random from the NSS library, despite the NSS library
1654 itself already seeding its internal state. This process can block
1655 pluto for an extended time during startup, depending on the entropy
1656 of the system. Therefore, the default is to not perform this
1657 redundant seeding. If specifying a value, it is recommended to
1658 specify at least 460 bits (for FIPS) or 440 bits (for BSI).
1659 ikev1-secctx-attr-type
1661 The value for the IKEv1 IPsec SA security context attribute
1662 identifier that is used for Labeled IPsec. Defaults to the private
1663 use IANA value 32001 from the IPsec SA attributes registry. Old
1664 openswan versions might still be using the (stolen) value 10, which
1665 has since been assigned by IANA for something else. Other values
1666 are not recommended unless IANA assigns an actual value for this
1667 option. Labeled IPsec using IKEv2 does not use this option, it only
1668 uses an IANA allocated Notify number. See also policy-label.
1669 ikev1-policy
1671 What to do with received IKEv1 packets. Valid options are accept
1672 (default), reject which will reply with an error, and drop which
1673 will silently drop any received IKEv1 packet. If this option is set
1674 to drop or reject, an attempt to load an IKEv1 connection will
1675 fail, as these connections would never be able to receive a packet
1676 for processing.
1677 crlcheckinterval
1679 interval expressed in second units, for example crlcheckinterval=8h
1680 for 8 hours, after which pluto will fetch new Certificate
1681 Revocation List (CRL) from crl distribution points. List of used
1682 CRL distribution points are collected from CA certificates and end
1683 certificates. Loaded X.509 CRL's are verified to be valid and
1684 updates are imported to NSS database. If set to 0, which is also
1685 the default value if this option is not specified, CRL updating is
1686 disabled.
1687 crl-strict
1689 if not set, pluto is tolerant about missing or expired X.509
1690 Certificate Revocation Lists (CRL's), and will allow peer
1691 certificates as long as they do not appear on an expired CRL. When
1692 this option is enabled, all connections with an expired or missing
1693 CRL will be denied. Active connections will be terminated at rekey
1694 time. This setup is more secure, but vulnerable to downtime if the
1695 CRL expires. Acceptable values are yes or no (the default). This
1696 option used to be called strictcrlpolicy.
1697 curl-iface
1699 The name of the interface that is used for CURL lookups. This is
1700 needed on rare situations where the interface needs to be forced to
1701 be different from the default interface used based on the routing
1702 table.
1703 curl-timeout
1705 The timeout for the curl library calls used to fetch CRL and OCSP
1706 requests. The default is 5s.
1707 ocsp-enable
1709 Whether to perform Online Certificate Store Protocol ("OCSP")
1710 checks on those certificates that have an OCSP URI defined.
1711 Acceptable values are yes or no (the default).
1712 ocsp-strict
1714 if set to no, pluto is tolerant about failing to obtain an OCSP
1715 responses and a certificate is not rejected when the OCSP request
1716 fails, only when the OCSP request succeeds and lists the
1717 certificate as revoked. If set to yes, any failure on obtaining an
1718 OCSP status for a certificate will be fatal and the certificate
1719 will be rejected. Acceptable values are yes or no (the default).
1720 The strict mode refers to the NSS
1722 ocspMode_FailureIsVerificationFailure mode, while non-strict mode
1723 refers to the NSS ocspMode_FailureIsNotAVerificationFailure mode.
1724 ocsp-method
1726 The HTTP methods used for fetching OCSP data. Valid options are get
1727 (the default) and post. Note that this behaviour depends on the NSS
1728 crypto library that is actually performing the fetching. When set
1729 to the get method, post is attempted only as fallback in case of
1730 failure. When set to post, only the post method is ever used.
1731 ocsp-timeout
1733 The time until an OCSP request is aborted and considered failed.
1734 The default value is 2 seconds.
1735 ocsp-uri
1737 The URI to use for OCSP requests instead of the default OCSP URI
1738 listed in the CA certificate. This requires the ocsp-trustname
1739 option to be set to the nick (friendly name) of the OCSP server
1740 certificate, which needs to be present in the NSS database. These
1741 option combined with the next option sets the OCSP default
1742 responder.
1743 ocsp-trustname
1745 The nickname of the certificate that has been imported into the NSS
1746 database of the server handling the OCSP requests. This requires
1747 the ocsp-uri option to be set as well. This option and the previous
1748 options sets the OCSP default responder.
1749 ocsp-cache-size
1751 The maximum size (in number of certificates) of OCSP responses that
1752 will be kept in the cache. The default is 1000. Setting this value
1753 to 0 means the cache is disabled.
1754 ocsp-cache-min-age
1756 The minimum age (in seconds) before a new fetch will be attempted.
1757 The default is 1 hour.
1758 ocsp-cache-max-age
1760 The maximum age (in seconds) before a new fetch will be attempted.
1761 The default is 1 day.
1762 syslog
1764 the syslog(2) “facility” name and priority to use for
1765 startup/shutdown log messages, default daemon.error.
1766 plutodebug
1768 how much Pluto debugging output should be logged. An empty value,
1769 or the magic value none, means no debug output (the default).
1770 Otherwise only the specified types of output (a quoted list, names
1771 without the --debug- prefix, separated by white space) are enabled;
1772 The current option values are base that represents moderate amounts
1774 of information, cpu-usage for getting timing/load based information
1775 (best used without any other debugging options), crypt for all
1776 crypto related operations and tmi (Too Much Information) for
1777 excessive logging. To log any sensitive private key or password
1778 material, use the special private value.
1779 The old plutodebug options (control, controlmore, x509, kernel,
1781 etc) are mapped to either base or tmi. Note that all maps to base
1782 and not tmi.
1783 uniqueids
1785 Whether IDs should be considered identifying remote parties
1786 uniquely. Acceptable values are yes (the default) and no.
1787 Participant IDs normally are unique, so a new connection instance
1788 using the same remote ID is almost invariably intended to replace
1789 an old existing connection.
1790 When the connection is defined to be a server (using xauthserver=)
1792 and the connection policy is authby=secret, this option is ignored
1793 (as of 3.20) and old connections will never be replaced. This
1794 situation is commonly known as clients using a "Group ID".
1795 This option may disappear in the near future. People using
1797 identical X.509 certificates on multiple devices are urged to
1798 upgrade to use separate certificates per client and device.
1799 logfile
1801 do not use syslog, but rather log to stderr, and direct stderr to
1802 the argument file. This option used to be called plutostderrlog=
1803 logappend
1805 If pluto is instructed to log to a file using logfile=, this option
1806 determines whether the log file should be appended to or
1807 overwritten. Valid options are yes (the default) to append and no
1808 to overwrite. Since on modern systems, pluto is restarted by other
1809 daemons, such as systemd, this option should be left at its default
1810 yes value to preserve the log entries of previous runs of pluto.
1811 The option is mainly of use for running the test suite, which needs
1812 to create new log files from scratch.
1813 logip
1815 If pluto is instructed to log the IP address of incoming
1816 connections. Valid options are yes (the default) and no. Note that
1817 this only affects regular logging. Any enabled debugging via
1818 plutodebug= will still contain IP addresses of peers. This option
1819 is mostly meant for servers that want to avoid logging IP addresses
1820 of incoming clients. Other identifiable information might still be
1821 logged, such as ID payloads and X.509 certificate details. When
1822 using ID of type IP address, this option will not hide the actual
1823 IP address as part of the ID. Most deployments will not want to
1824 change this from the default. If logging of IP addresses is
1825 unwanted, audit-log=no should also be set.
1826 audit-log
1828 Whether pluto should produce Linux Auditing System log messages. If
1829 enabled, pluto will log start, stop and fail for the negotiation of
1830 IKE and IPsec SA's. The kernel will also log success and failures
1831 for actually adding and removing IPsec SA's from the kernel's SADB.
1832 Valid options are yes(the default) and no. On non-Linux systems,
1833 this option is ignored. If enabled but the kernel is lacking audit
1834 support, audit messages are not sent. If the kernel has audit
1835 support and using it fails, pluto will abort. Note that for
1836 compliance reasons, audit log messages contain the relevant IP
1837 addresses, even if logip=no.
1838 logtime
1840 When pluto is directed to log to a file using logfile=, this option
1841 determines whether or not to log the current timestamp as prefix.
1842 Values are yes (the default) or no. The no value can be used to
1843 create logs without ephemeral timestamps, such as those created
1844 when running the test suite. This option used to be called
1845 plutostderrlogtime=
1846 ddos-mode
1848 The startup mode of the DDoS defense mechanism. Acceptable values
1849 are busy, unlimited or auto (the default). This option can also be
1850 given to the IKE daemon while running, for example by issuing ipsec
1851 whack --ddos--busy. When in busy mode, pluto activates anti-DDoS
1852 counter measures. Currently, counter measures consist of requiring
1853 IKEv2 anti-DDoS cookies on new incoming IKE requests, and a more
1854 aggressive cleanup of partially established or AUTH_NULL
1855 connections.
1856 ddos-ike-threshold
1858 The number of half-open IKE SAs before the pluto IKE daemon will be
1859 placed in busy mode. When in busy mode, pluto activates anti-DDoS
1860 counter measures. The default is 25000. See also ddos-mode and
1861 ipsec whack --ddos-XXX.
1862 global-redirect
1864 Whether to send requests for the remote peer to redirect IKE/IPsec
1865 SA's during IKE_SA_INIT. Valid options are no (the default), yes
1866 and auto, where auto means that the requests will be sent if DDoS
1867 mode is active (see ddos-mode). If set, the option
1868 global-redirect-to= must also be set to indicate where to redirect
1869 peers to. For specific connection redirection after IKE SA
1870 authentication, see the send-redirect= and redirect-to= options.
1871 This configuration can be changed at runtime via the ipsec whack
1872 --global-redirect command.
1873 global-redirect-to
1875 Where to send remote peers to via the global-redirect option. This
1876 can be a list, or a single entry, of IP addresses or hostnames
1877 (FQDNs). If there is a list of entries, they must be separated with
1878 comma's. One specified entry means all peers will be redirected to
1879 it, while multiple specified entries means peers will be evenly
1880 distributed across the specified servers. This configuration can be
1881 changed at runtime via the ipsec whack --global-redirect-to
1882 command.
1883 max-halfopen-ike
1885 The number of half-open IKE SAs before the IKE daemon starts
1886 refusing all new IKE attempts. Established IKE peers are not
1887 affected. The default value is 50000.
1888 shuntlifetime
1890 The time until bare shunts (kernel policies not associated with
1891 connections) are deleted from the kernel. The default value is 15m.
1892 When using Opportunistic Encryption to a specific host fails, the
1893 system will either install a %pass or %hold shunt to let the
1894 traffic out clear text or block it. During the the shuntlifetime,
1895 no new Opportunistic Encryption attempt will be started, although
1896 the system will still respond to incoming OE requests from the
1897 remote IP. See also failureshunt and negotiationshunt
1898 xfrmlifetime
1900 The time in seconds until the NETKEY/XFRM acquire state times out.
1901 The default value is 300 seconds. For auto=ondemand connections and
1902 Opportunistic connections an IPsec policy is installed in the
1903 kernel. If an incoming or outgoing packet matches this policy, a
1904 state is created in the kernel and the kernel sends an ACQUIRE
1905 message to the IKE daemon pluto. While this state is in place, no
1906 new acquires will come in for this connection. The default should
1907 be fine for most people. One use case of shortening these is if
1908 opportunistc encryption is used towards cloud instances that can
1909 quickly re-use IP addresses. This value is only used during the
1910 libreswan startup process by the ipsec _stackmanager helper. See
1911 also failureshunt and negotiationshunt
1912 dumpdir
1914 in what directory should things started by setup (notably the Pluto
1915 daemon) be allowed to dump core? The default value is
1916 /var/run/pluto. When SELinux runs in enforced mode, changing this
1917 requires a similar change in the SELinux policy for the pluto
1918 daemon.
1919 statsbin
1921 This option specifies an optional external program to report tunnel
1922 state changes too. The default is not to report tunnel state
1923 changes. This program can be used to notify the user's desktop
1924 (dbus, NetworkManager) or to report tunnel changes to a central
1925 logging server.
1926 ipsecdir
1928 Specifies a directory for administrator-controlled configuration
1929 files and directories. The default value is /etc/ipsec.d. It may
1930 contain the following files and directories:
1931 passwd
1933 (optional) for XAUTH support if not using PAM (this file should
1934 not be world-readable). See README.XAUTH for more information.
1935 nsspassword
1937 (optional) passwords needed to unlock the NSS database in
1938 /var/lib/ipsec/nss (this file should not be world-readable).
1939 See README.nss for more information.
1940 policies/
1942 a directory containing policy group configuration information.
1943 See POLICY GROUP FILES in this document for more information.
1944 cacerts/
1946 DEPRECATED: a directory to store trust anchors (root
1947 certificate authority certificates). The preferred (and
1948 default) approach is to store CA certs in the NSS database
1949 instead. See README.nss for more information.
1950 crls/
1952 DEPRECATED: a directory to store certificate revocation lists.
1953 The preferred (and default) approach is to store CRLs in the
1954 NSS database instead. See README.nss for more information.
1955 When SELinux runs in enforced mode, changing this requires a
1957 similar change in the SELinux policy for the pluto daemon.
1958 nssdir
1960 Specifies a directory for NSS database files. The default value is
1961 /var/lib/ipsec/nss. It may contain the following files:
1962 pkcs11.txt
1964 Detailed info about NSS database creation parameteres.
1965 cert9.db
1967 NSS Certificate database.
1968 key4.db
1970 NSS Key database.
1971 When SELinux runs in enforced mode, changing this requires a
1973 similar change in the SELinux policy for the pluto daemon.
1974 secretsfile
1976 pathname of the file that stores the secret credentials such as
1977 preshared keys (PSKs). See man ipsec.secrets for the syntax. The
1978 default value is /etc/ipsec.secrets.
1979 seccomp
1981 Set the seccomp kernel syscall whitelisting feature. When set to
1982 enabled, if pluto calls a syscall that is not on the compiled-in
1983 whitelist, the kernel will assume an exploit is attempting to use
1984 pluto for malicious access to the system and terminate the pluto
1985 daemon. When set to tolerant, the kernel will only block the rogue
1986 syscall and pluto will attempt to continue. If set to disabled,
1987 pluto is allowed to call any syscall offered by the kernel,
1988 although it might be restricted via other security mechanisms, such
1989 as capabilities, SElinux, AppArmor or other OS security features.
1990 The current default is disabled, but it is expected that in the
1992 future this feature will be enabled on all supported operating
1993 systems. Similarly, it is expected that further privilege
1994 separation will reduce the allowed syscalls - for example for the
1995 crypto helpers or DNS helpers.
1996 Warning: The restrictions of pluto are inherited by the updown
1998 scripts, so these scripts are also not allowed to use syscalls that
1999 are forbidden for pluto.
2000 This feature can be tested using ipsec whack --seccomp-crashtest.
2002 Warning: With seccomp=enabled, pluto will be terminated by the
2003 kernel. With seccomp=tolerant or seccomp=disabled, pluto will
2004 report the results of the seccomp test. SECCOMP will log the
2005 forbidden syscall numbers to the audit log, but only with
2006 seccomp=enabled. The tool scmp_sys_resolver from the libseccomp
2007 development package can be used to translate the syscall number
2008 into a name. See programs/pluto/pluto_seccomp.c for the list of
2009 allowed syscalls.
2010 dnssec-enable
2012 Whether pluto should perform dnssec validation using libunbound,
2013 provided libreswan was compiled with USE_DNSSEC. A value of yes
2014 (the default) means pluto should perform DNSSEC validation. Note
2015 that pluto reads the file /etc/resolv.conf to determine which
2016 nameservers to use.
2017 dnssec-rootkey-file
2019 The location of the DNSSEC root zone public key file. The default
2020 is /var/lib/unbound/root.key but this can be changed at compile
2021 time.
2022 dnssec-anchors
2024 The location of a file containing additional DNSSEC Trust Anchors.
2025 This can be used when a network is using split-DNS and the internal
2026 hierarchy is using DNSSEC trust anchors. There is no default value.
2027
2029 The system automatically defines several conns to implement default
2030 policy groups. Each can be overridden by explicitly defining a new conn
2031 with the same name. If the new conn has auto=ignore, the definition is
2032 suppressed.
2033 Here are the automatically supplied definitions.
2035 conn clear
2038 type=passthrough
2039 authby=never
2040 left=%defaultroute
2041 right=%group
2042 auto=route
2043 conn clear-or-private
2045 type=passthrough
2046 left=%defaultroute
2047 leftid=%myid
2048 right=%opportunisticgroup
2049 failureshunt=passthrough
2050 keyingtries=3
2051 ikelifetime=1h
2052 salifetime=1h
2053 rekey=no
2054 auto=route
2055 conn private-or-clear
2057 type=tunnel
2058 left=%defaultroute
2059 leftid=%myid
2060 right=%opportunisticgroup
2061 failureshunt=passthrough
2062 keyingtries=3
2063 ikelifetime=1h
2064 salifetime=1h
2065 rekey=no
2066 auto=route
2067 conn private
2069 type=tunnel
2070 left=%defaultroute
2071 leftid=%myid
2072 right=%opportunisticgroup
2073 failureshunt=drop
2074 keyingtries=3
2075 ikelifetime=1h
2076 salifetime=1h
2077 rekey=no
2078 auto=route
2079 conn block
2081 type=reject
2082 authby=never
2083 left=%defaultroute
2084 right=%group
2085 auto=route
2086 # default policy
2088 conn packetdefault
2089 type=tunnel
2090 left=%defaultroute
2091 leftid=%myid
2092 left=0.0.0.0/0
2093 right=%opportunistic
2094 failureshunt=passthrough
2095 keyingtries=3
2096 ikelifetime=1h
2097 salifetime=1h
2098 rekey=no
2099 auto=route
2100 These conns are not affected by anything in conn %default. They will
2102 only work if %defaultroute works. The leftid will be the interfaces IP
2103 address; this requires that reverse DNS records be set up properly.
2104 The implicit conns are defined after all others. It is appropriate and
2106 reasonable to use also=private-or-clear (for example) in any other
2107 opportunistic conn.
2108
2110 The optional files under /etc/ipsec.d/policies, including
2111 /etc/ipsec.d/policies/clear
2114 /etc/ipsec.d/policies/clear-or-private
2115 /etc/ipsec.d/policies/private-or-clear
2116 /etc/ipsec.d/policies/private
2117 /etc/ipsec.d/policies/block
2118 may contain policy group configuration information to supplement
2121 ipsec.conf. Their contents are not security-sensitive.
2122 These files are text files. Each consists of a list of CIDR blocks, one
2124 per line. White space followed by # followed by anything to the end of
2125 the line is a comment and is ignored, as are empty lines.
2126 A connection in ipsec.conf that has right=%group or
2128 right=%opportunisticgroup is a policy group connection. When a policy
2129 group file of the same name is loaded, with
2130 ipsec auto --rereadgroups
2132 or at system start, the connection is instantiated such that each CIDR
2134 block serves as an instance's right value. The system treats the
2135 resulting instances as normal connections.
2136 For example, given a suitable connection definition private, and the
2138 file /etc/ipsec.d/policies/private with an entry 192.0.2.3, the system
2139 creates a connection instance private#192.0.2.3. This connection
2140 inherits all details from private, except that its right client is
2141 192.0.2.3.
2142
2144 The standard Libreswan install includes several policy groups which
2145 provide a way of classifying possible peers into IPsec security
2146 classes: private (talk encrypted only), private-or-clear (prefer
2147 encryption), clear-or-private (respond to requests for encryption),
2148 clear and block. Implicit policy groups apply to the local host only,
2149 and are implemented by the IMPLICIT CONNECTIONS described above.
2150
2152 When choosing a connection to apply to an outbound packet caught with a
2153 %trap, the system prefers the one with the most specific eroute that
2154 includes the packet's source and destination IP addresses. Source
2155 subnets are examined before destination subnets. For initiating, only
2156 routed connections are considered. For responding, unrouted but added
2157 connections are considered.
2158 When choosing a connection to use to respond to a negotiation that
2160 doesn't match an ordinary conn, an opportunistic connection may be
2161 instantiated. Eventually, its instance will be /32 -> /32, but for
2162 earlier stages of the negotiation, there will not be enough information
2163 about the client subnets to complete the instantiation.
2164
2166 /etc/ipsec.conf
2167 /etc/ipsec.d/policies/clear
2168 /etc/ipsec.d/policies/clear-or-private
2169 /etc/ipsec.d/policies/private-or-clear
2170 /etc/ipsec.d/policies/private
2171 /etc/ipsec.d/policies/block
2172
2174 ipsec(8), ipsec_auto(8), ipsec_rsasigkey(8)
2175
2177 Designed for the FreeS/WAN project <https://www.freeswan.org> by Henry
2178 Spencer.
2179
2181 Before reporting new bugs, please ensure you are using the latest
2182 version of Libreswan, and if not using KLIPS, please ensure you are
2183 using the latest kernel code for your IPsec stack.
2184 When type or failureshunt is set to drop or reject, Libreswan blocks
2186 outbound packets using eroutes, but assumes inbound blocking is handled
2187 by the firewall. Libreswan offers firewall hooks via an “updown”
2188 script. However, the default ipsec _updown provides no help in
2189 controlling a modern firewall.
2190 Including attributes of the keying channel (authentication methods,
2192 ikelifetime, etc.) as an attribute of a connection, rather than of a
2193 participant pair, is dubious and incurs limitations.
2194 The use of %any with the protoport= option is ambiguous. Should the SA
2196 permits any port through or should the SA negotiate any single port
2197 through? The first is a basic conn with a wildcard. The second is a
2198 template. The second is the current behaviour, and it's wrong for quite
2199 a number of uses involving TCP. The keyword %one may be introduced in
2200 the future to separate these two cases.
2201 It would be good to have a line-continuation syntax, especially for the
2203 very long lines involved in RSA signature keys.
2204 First packet caching is only implemented for the KLIPS(NG) and MAST
2206 stacks. NETKEY returns POSIX-breaking responses, visible as connect:
2207 Resource temporarily unavailable errors. This affects Opportunistic
2208 Encryption and DPD. Functionality on the BSD and Windows stacks is
2209 unknown.
2210 Some state information is only available when using KLIPS, and will
2212 return errors on other IPsec stacks. These include ipsec eroute, ipsec
2213 spi and ipsec look.
2214 Multiple L2TP clients behind the same NAT router, and multiple L2TP
2216 clients behind different NAT routers using the same Virtual IP is
2217 currently only working for the KLIPSNG stack.
2218 The ability to specify different identities, authby, and public keys
2220 for different automatic-keyed connections between the same participants
2221 is misleading; this doesn't work dependably because the identity of the
2222 participants is not known early enough. This is especially awkward for
2223 the “Road Warrior” case, where the remote IP address is specified as
2224 0.0.0.0, and that is considered to be the “participant” for such
2225 connections.
2226 If conns are to be added before DNS is available, left=FQDN,
2228 leftnextop=FQDN, and leftrsasigkey=%dnsonload will fail.
2229 ipsec_pluto(8) does not actually use the public key for our side of a
2230 conn but it isn't generally known at a add-time which side is ours
2231 (Road Warrior and Opportunistic conns are currently exceptions).
2232 The myid option does not affect explicit
2234 ipsec auto --add or ipsec auto --replace commands for implicit conns.
2235
2237 Paul Wouters
2238 documenter
2239libreswan 02/21/2021 IPSEC.CONF(5)