1unbound-anchor(8) unbound 1.19.0 unbound-anchor(8)
2
6 unbound-anchor - Unbound anchor utility.
7
9 unbound-anchor [opts]
10
12 Unbound-anchor performs setup or update of the root trust anchor for
13 DNSSEC validation. The program fetches the trust anchor with the
14 method from RFC7958 when regular RFC5011 update fails to bring it up to
15 date. It can be run (as root) from the commandline, or run as part of
16 startup scripts. Before you start the unbound(8) DNS server.
17 Suggested usage:
19 # in the init scripts.
21 # provide or update the root anchor (if necessary)
22 unbound-anchor -a "/var/lib/unbound/root.key"
23 # Please note usage of this root anchor is at your own risk
24 # and under the terms of our LICENSE (see source).
25 #
26 # start validating resolver
27 # the unbound.conf contains:
28 # auto-trust-anchor-file: "/var/lib/unbound/root.key"
29 unbound -c unbound.conf
30 This tool provides builtin default contents for the root anchor and
32 root update certificate files.
33 It tests if the root anchor file works, and if not, and an update is
35 possible, attempts to update the root anchor using the root update cer‐
36 tificate. It performs a https fetch of root-anchors.xml and checks the
37 results (RFC7958), if all checks are successful, it updates the root
38 anchor file. Otherwise the root anchor file is unchanged. It performs
39 RFC5011 tracking if the DNSSEC information available via the DNS makes
40 that possible.
41 It does not perform an update if the certificate is expired, if the
43 network is down or other errors occur.
44 The available options are:
46 -a file
48 The root anchor key file, that is read in and written out. De‐
49 fault is /var/lib/unbound/root.key. If the file does not exist,
50 or is empty, a builtin root key is written to it.
51 -c file
53 The root update certificate file, that is read in. Default is
54 /etc/unbound/icannbundle.pem. If the file does not exist, or is
55 empty, a builtin certificate is used.
56 -l List the builtin root key and builtin root update certificate on
58 stdout.
59 -u name
61 The server name, it connects to https://name. Specify without
62 https:// prefix. The default is "data.iana.org". It connects
63 to the port specified with -P. You can pass an IPv4 address or
64 IPv6 address (no brackets) if you want.
65 -S Do not use SNI for the HTTPS connection. Default is to use SNI.
67 -b address
69 The source address to bind to for domain resolution and contact‐
70 ing the server on https. May be either an IPv4 address or IPv6
71 address (no brackets).
72 -x path
74 The pathname to the root-anchors.xml file on the server. (forms
75 URL with -u). The default is /root-anchors/root-anchors.xml.
76 -s path
78 The pathname to the root-anchors.p7s file on the server. (forms
79 URL with -u). The default is /root-anchors/root-anchors.p7s.
80 This file has to be a PKCS7 signature over the xml file, using
81 the pem file (-c) as trust anchor.
82 -n name
84 The emailAddress for the Subject of the signer's certificate
85 from the p7s signature file. Only signatures from this name are
86 allowed. default is dnssec@iana.org. If you pass "" then the
87 emailAddress is not checked.
88 -4 Use IPv4 for domain resolution and contacting the server on
90 https. Default is to use IPv4 and IPv6 where appropriate.
91 -6 Use IPv6 for domain resolution and contacting the server on
93 https. Default is to use IPv4 and IPv6 where appropriate.
94 -f resolv.conf
96 Use the given resolv.conf file. Not enabled by default, but you
97 could try to pass /etc/resolv.conf on some systems. It contains
98 the IP addresses of the recursive nameservers to use. However,
99 since this tool could be used to bootstrap that very recursive
100 nameserver, it would not be useful (since that server is not up
101 yet, since we are bootstrapping it). It could be useful in a
102 situation where you know an upstream cache is deployed (and run‐
103 ning) and in captive portal situations.
104 -r root.hints
106 Use the given root.hints file (same syntax as the BIND and Un‐
107 bound root hints file) to bootstrap domain resolution. By de‐
108 fault a list of builtin root hints is used. Unbound-anchor goes
109 to the network itself for these roots, to resolve the server (-u
110 option) and to check the root DNSKEY records. It does so, be‐
111 cause the tool when used for bootstrapping the recursive re‐
112 solver, cannot use that recursive resolver itself because it is
113 bootstrapping that server.
114 -R Allow fallback from -f resolv.conf file to direct root servers
116 query. It allows you to prefer local resolvers, but fallback
117 automatically to direct root query if they do not respond or do
118 not support DNSSEC.
119 -v More verbose. Once prints informational messages, multiple times
121 may enable large debug amounts (such as full certificates or
122 byte-dumps of downloaded files). By default it prints almost
123 nothing. It also prints nothing on errors by default; in that
124 case the original root anchor file is simply left undisturbed,
125 so that a recursive server can start right after it.
126 -C unbound.conf
128 Debug option to read unbound.conf into the resolver process
129 used.
130 -P port
132 Set the port number to use for the https connection. The de‐
133 fault is 443.
134 -F Debug option to force update of the root anchor through down‐
136 loading the xml file and verifying it with the certificate. By
137 default it first tries to update by contacting the DNS, which
138 uses much less bandwidth, is much faster (200 msec not 2 sec),
139 and is nicer to the deployed infrastructure. With this option,
140 it still attempts to do so (and may verbosely tell you), but
141 then ignores the result and goes on to use the xml fallback
142 method.
143 -h Show the version and commandline option help.
145
147 This tool exits with value 1 if the root anchor was updated using the
148 certificate or if the builtin root-anchor was used. It exits with code
149 0 if no update was necessary, if the update was possible with RFC5011
150 tracking, or if an error occurred.
151 You can check the exit value in this manner:
153 unbound-anchor -a "root.key" || logger "Please check root.key"
154 Or something more suitable for your operational environment.
155
157 The root keys and update certificate included in this tool are provided
158 for convenience and under the terms of our license (see the LICENSE
159 file in the source distribution or https://github.com/NLnetLabs/un‐
160 bound/blob/master/LICENSE) and might be stale or not suitable to your
161 purpose.
162 By running "unbound-anchor -l" the keys and certificate that are con‐
164 figured in the code are printed for your convenience.
165 The build-in configuration can be overridden by providing a root-cert
167 file and a rootkey file.
168
170 /var/lib/unbound/root.key
171 The root anchor file, updated with 5011 tracking, and read and
172 written to. The file is created if it does not exist.
173 /etc/unbound/icannbundle.pem
175 The trusted self-signed certificate that is used to verify the
176 downloaded DNSSEC root trust anchor. You can update it by
177 fetching it from https://data.iana.org/root-anchors/icannbun‐
178 dle.pem (and validate it). If the file does not exist or is
179 empty, a builtin version is used.
180 https://data.iana.org/root-anchors/root-anchors.xml
182 Source for the root key information.
183 https://data.iana.org/root-anchors/root-anchors.p7s
185 Signature on the root key information.
186
188 unbound.conf(5), unbound(8).
189NLnet Labs Nov 8, 2023 unbound-anchor(8)