1tcpbridge(1)                     User Commands                    tcpbridge(1)
2
3
4

NAME

6       tcpbridge - Bridge network traffic across two interfaces
7

SYNOPSIS

9       tcpbridge [-flags] [-flag [value]] [--option-name[[=| ]value]]
10
11       All arguments must be options.
12
13       tcpbridge is a tool for selectively bridging network traffic across two
14       interfaces and optionally modifying the packets in between
15

DESCRIPTION

17       The basic operation of tcpbridge is to be a network bridge between  two
18       subnets.  All packets received on one interface are sent via the other.
19
20       Optionally,  packets  can  be  edited in a variety of ways according to
21       your needs.
22
23       For more details, please see the  Tcpreplay  Manual  at:  http://tcpre
24       play.appneta.com
25

OPTIONS

27
28       -r string, --portmap=string
29              Rewrite TCP/UDP ports.  This option may appear up to 9999 times.
30
31              Specify  a  list  of comma delimited port mappings consisting of
32              colon delimited port number pairs.  Each  colon  delimited  port
33              pair  consists  of the port to match followed by the port number
34              to rewrite.
35
36              Examples:
37                  --portmap=80:8000 --portmap=8080:80    # 80->8000 and 8080->80
38                  --portmap=8000,8080,88888:80           # 3 different ports become 80
39                  --portmap=8000-8999:80                 # ports 8000 to 8999 become 80
40
41       -s number, --seed=number
42              Randomize src/dst IPv4/v6 addresses w/ given seed.  This  option
43              may appear up to 1 times.  This option must not appear in combi‐
44              nation with any of the following options: fuzz-seed.   This  op‐
45              tion takes an integer number as its argument.
46
47              Causes the source and destination IPv4/v6 addresses to be pseudo
48              randomized  but  still  maintain  client/server   relationships.
49              Since  the randomization is deterministic based on the seed, you
50              can reuse the same seed value to recreate the traffic.
51
52       -N string, --pnat=string
53              Rewrite IPv4/v6 addresses using pseudo-NAT.  This option may ap‐
54              pear  up to 2 times.  This option must not appear in combination
55              with any of the following options: srcipmap.
56
57              Takes a comma delimited series of colon delimited CIDR  netblock
58              pairs.   Each netblock pair is evaluated in order against the IP
59              addresses.  If the IP address in the packet  matches  the  first
60              netblock,  it  is  rewritten using the second netblock as a mask
61              against the high order bits.
62
63              IPv4 Example:
64                  --pnat=192.168.0.0/16:10.77.0.0/16,172.16.0.0/12:10.1.0.0/24
65              IPv6 Example:
66                  --pnat=[2001:db8::/32]:[dead::/16],[2001:db8::/32]:[::ffff:0:0/96]
67
68       -S string, --srcipmap=string
69              Rewrite source IPv4/v6 addresses using pseudo-NAT.  This  option
70              may appear up to 1 times.  This option must not appear in combi‐
71              nation with any of the following options: pnat.
72
73              Works just like the --pnat option, but only affects  the  source
74              IP addresses in the IPv4/v6 header.
75
76       -D string, --dstipmap=string
77              Rewrite  destination  IPv4/v6  addresses using pseudo-NAT.  This
78              option may appear up to 1 times.  This option must not appear in
79              combination with any of the following options: pnat.
80
81              Works just like the --pnat option, but only affects the destina‐
82              tion IP addresses in the IPv4/v6 header.
83
84       -e string, --endpoints=string
85              Rewrite IP addresses to be between two endpoints.   This  option
86              may  appear  up to 1 times.  This option must appear in combina‐
87              tion with the following options: cachefile.
88
89              Takes a pair of colon delimited IPv4/v6 addresses which will  be
90              used  to  rewrite all traffic to appear to be between the two IP
91              addresses.
92
93              IPv4 Example:
94                  --endpoints=172.16.0.1:172.16.0.2
95              IPv6 Example:
96                  --endpoints=[2001:db8::dead:beef]:[::ffff:0:0:ac:f:0:2]
97
98       --tcp-sequence=number
99              Change TCP Sequence (and ACK) numbers /w given seed.   This  op‐
100              tion takes an integer number as its argument.  The value of num‐
101              ber is constrained to being:
102                  greater than or equal to 1
103              The default number for this option is:
104                   0
105
106              Change all TCP sequence numbers, and related sequence-acknowl‐
107              edgement numbers.  They will be shifted by a random amount based
108              on the provided seed.
109
110       -b, --skipbroadcast
111              Skip rewriting broadcast/multicast IPv4/v6 addresses.
112
113              By default --seed, --pnat and --endpoints will rewrite broadcast
114              and multicast IPv4/v6 and MAC addresses. Setting this flag will
115              keep broadcast/multicast IPv4/v6 and MAC addresses from being
116              rewritten.
117
118       -C, --fixcsum
119              Force recalculation of IPv4/TCP/UDP header checksums.
120
121              Causes each IPv4/v6 packet to have their checksums recalculated
122              and fixed.  Automatically enabled for packets modified with
123              --seed, --pnat, --endpoints or --fixlen.
124
125       -m number, --mtu=number
126              Override default MTU length (1500 bytes).  This option may ap‐
127              pear up to 1 times.  This option takes an integer number as its
128              argument.  The value of number is constrained to being:
129                  in the range  1 through MAX_SNAPLEN
130
131              Override the default 1500 byte MTU size for determining the max‐
132              imum padding length (--fixlen=pad) or when truncating (--mtu-
133              trunc).
134
135       --mtu-trunc
136              Truncate packets larger then specified MTU.  This option may ap‐
137              pear up to 1 times.
138
139              Similar to --fixlen, this option will truncate data in packets
140              from Layer 3 and above to be no larger then the MTU.
141
142       -E, --efcs
143              Remove Ethernet checksums (FCS) from end of frames.
144
145              Note, this option is pretty dangerous!  We do not actually check
146              to see if a FCS actually exists in the frame, we just blindly
147              delete the last 4 bytes.  Hence, you should only use this if you
148              know know that your OS provides the FCS when reading raw pack‐
149              ets.
150
151       --ttl=string
152              Modify the IPv4/v6 TTL/Hop Limit.
153
154              Allows you to modify the TTL/Hop Limit of all the IPv4/v6 pack‐
155              ets.  Specify a number to hard-code the value or +/-value to in‐
156              crease or decrease by the value provided (limited to 1-255).
157
158              Examples:
159                  --ttl=10
160                  --ttl=+7
161                  --ttl=-64
162
163       --tos=number
164              Set the IPv4 TOS/DiffServ/ECN byte.  This option may appear up
165              to 1 times.  This option takes an integer number as its argu‐
166              ment.  The value of number is constrained to being:
167                  in the range  0 through 255
168
169              Allows you to override the TOS (also known as DiffServ/ECN)
170              value in IPv4.
171
172       --tclass=number
173              Set the IPv6 Traffic Class byte.  This option may appear up to 1
174              times.  This option takes an integer number as its argument.
175              The value of number is constrained to being:
176                  in the range  0 through 255
177
178              Allows you to override the IPv6 Traffic Class field.
179
180       --flowlabel=number
181              Set the IPv6 Flow Label.  This option may appear up to 1 times.
182              This option takes an integer number as its argument.  The value
183              of number is constrained to being:
184                  in the range  0 through 1048575
185
186              Allows you to override the 20bit IPv6 Flow Label field.  Has no
187              effect on IPv4 packets.
188
189       -F string, --fixlen=string
190              Pad or truncate packet data to match header length.  This option
191              may appear up to 1 times.
192
193              Packets may be truncated during capture if the snaplen is
194              smaller then the packet.  This option allows you to modify the
195              packet to pad the packet back out to the size stored in the
196              IPv4/v6 header or rewrite the IP header total length to reflect
197              the stored packet length.
198
199              pad Truncated packets will be padded out so that the packet
200              length matches the IPv4 total length
201
202              trunc Truncated packets will have their IPv4 total length field
203              rewritten to match the actual packet length
204
205              del Delete the packet
206
207       --fuzz-seed=number
208              Fuzz 1 in X packets. Edit bytes, length, or emulate packet drop.
209              This option takes an integer number as its argument.  The value
210              of number is constrained to being:
211                  greater than or equal to 0
212              The default number for this option is:
213                   0
214
215              This fuzzing was designed as to test layer 7 protocols such as
216              voip protocols.  It modifies randomly 1 out of X packets (where
217              X = --fuzz-factor) in order for stateful protocols to cover more
218              of their code.  The random fuzzing actions focus on data start
219              and end because it often is the part of the data application
220              protocols base their decisions on.
221
222              Possible fuzzing actions list:
223               * drop packet
224               * reduce packet size
225               * edit packet Bytes:
226                 * Not all Bytes have the same probability of appearance in
227              real life.
228                   Replace with 0x00, 0xFF, or a random byte with equal like‐
229              lihood.
230                 * Not all Bytes have the same significance in a packet.
231                   Replace the start, the end, or the middle of the packet
232              with equal likelihood.
233               * do nothing (7 out of 8 packets)
234
235       --fuzz-factor=number
236              Set the Fuzz 1 in X packet ratio (default 1 in 8 packets).  This
237              option must appear in combination with the following options:
238              fuzz-seed.  This option takes an integer number as its argument.
239              The value of number is constrained to being:
240                  greater than or equal to 1
241              The default number for this option is:
242                   8
243
244              Sets the ratio of for --fuzz-seed option. By default this value
245              is 8, which means 1 in 8 packets are modified by fuzzing. Note
246              that this ratio is based on the random number generated by the
247              supplied fuzz seed. Therefore by default you cannot expect that
248              exactly every eighth packet will be modified.
249
250       --skipl2broadcast
251              Skip rewriting broadcast/multicast Layer 2 addresses.
252
253              By default, editing Layer 2 addresses will rewrite broadcast and
254              multicast MAC addresses.   Setting this flag will keep broad‐
255              cast/multicast MAC addresses from being rewritten.
256
257       --dlt=string
258              Override output DLT encapsulation.  This option may appear up to
259              1 times.
260
261              By default, no DLT (data link type) conversion will be made.  To
262              change the DLT type of the output pcap, select one of the fol‐
263              lowing values:
264
265              enet Ethernet aka DLT_EN10MB
266
267              hdlc Cisco HDLC aka DLT_C_HDLC
268
269              jnpr_eth Juniper Ethernet DLT_C_JNPR_ETHER
270
271              pppserial PPP Serial aka DLT_PPP_SERIAL
272
273              user User specified Layer 2 header and DLT type
274
275       --enet-dmac=string
276              Override destination ethernet MAC addresses.  This option may
277              appear up to 1 times.
278
279              Takes a pair of comma deliminated ethernet MAC addresses which
280              will replace the destination MAC address of outbound packets.
281              The first MAC address will be used for the server to client
282              traffic and the optional second MAC address will be used for the
283              client to server traffic.
284
285              Example:
286                  --enet-dmac=00:12:13:14:15:16,00:22:33:44:55:66
287
288       --enet-smac=string
289              Override source ethernet MAC addresses.  This option may appear
290              up to 1 times.
291
292              Takes a pair of comma deliminated ethernet MAC addresses which
293              will replace the source MAC address of outbound packets.  The
294              first MAC address will be used for the server to client traffic
295              and the optional second MAC address will be used for the client
296              to server traffic.
297
298              Example:
299                  --enet-smac=00:12:13:14:15:16,00:22:33:44:55:66
300
301       --enet-subsmac=string
302              Substitute MAC addresses.  This option may appear up to 9999
303              times.
304
305              Allows you to rewrite ethernet MAC addresses of packets. It
306              takes comma delimited pair or MACs address and rewrites all oc‐
307              currences of the first MAC with the value of the second MAC.
308              Example:
309                  --enet-subsmac=00:12:13:14:15:16,00:22:33:44:55:66
310
311       --enet-mac-seed=number
312              Randomize MAC addresses.  This option may appear up to 1 times.
313              This option must not appear in combination with any of the fol‐
314              lowing options: enet-smac, enet-dmac, enet-subsmac.  This option
315              takes an integer number as its argument.
316
317              Allows you to randomize ethernet MAC addresses of packets,
318              mostly like what --seed option does for IPv4/IPv6 addresses.
319
320       --enet-mac-seed-keep-bytes=number
321              Randomize MAC addresses.  This option may appear up to 1 times.
322              This option must appear in combination with the following op‐
323              tions: enet-mac-seed.  This option takes an integer number as
324              its argument.  The value of number is constrained to being:
325                  in the range  1 through 6
326
327              Keep some bytes untouched when usinging --enet-mac-seed option.
328
329       --enet-vlan=string
330              Specify ethernet 802.1q VLAN tag mode.  This option may appear
331              up to 1 times.
332
333              Allows you to rewrite ethernet frames to add a 802.1q header to
334              standard 802.3 ethernet headers or remove the 802.1q VLAN tag
335              information.
336
337              add Rewrites the existing 802.3 ethernet header as an 802.1q
338              VLAN header
339
340              del Rewrites the existing 802.1q VLAN header as an 802.3 ether‐
341              net header
342
343       --enet-vlan-tag=number
344              Specify the new ethernet 802.1q VLAN tag value.  This option may
345              appear up to 1 times.  This option must appear in combination
346              with the following options: enet-vlan.  This option takes an in‐
347              teger number as its argument.  The value of number is con‐
348              strained to being:
349                  in the range  0 through 4095
350
351
352       --enet-vlan-cfi=number
353              Specify the ethernet 802.1q VLAN CFI value.  This option may ap‐
354              pear up to 1 times.  This option must appear in combination with
355              the following options: enet-vlan.  This option takes an integer
356              number as its argument.  The value of number is constrained to
357              being:
358                  in the range  0 through 1
359
360
361       --enet-vlan-pri=number
362              Specify the ethernet 802.1q VLAN priority.  This option may ap‐
363              pear up to 1 times.  This option must appear in combination with
364              the following options: enet-vlan.  This option takes an integer
365              number as its argument.  The value of number is constrained to
366              being:
367                  in the range  0 through 7
368
369
370       --hdlc-control=number
371              Specify HDLC control value.  This option may appear up to 1
372              times.  This option takes an integer number as its argument.
373
374              The Cisco HDLC header has a 1 byte "control" field.  Apparently
375              this should always be 0, but if you can use any 1 byte value.
376
377       --hdlc-address=number
378              Specify HDLC address.  This option may appear up to 1 times.
379              This option takes an integer number as its argument.
380
381              The Cisco HDLC header has a 1 byte "address" field which has two
382              valid values:
383
384              0x0F Unicast
385
386              0xBF Broadcast
387              You can however specify any single byte value.
388
389       --user-dlt=number
390              Set output file DLT type.  This option may appear up to 1 times.
391              This option takes an integer number as its argument.
392
393              Set the DLT value of the output pcap file.
394
395       --user-dlink=string
396              Rewrite Data-Link layer with user specified data.  This option
397              may appear up to 2 times.
398
399              Provide a series of comma deliminated hex values which will be
400              used to rewrite or create the Layer 2 header of the packets.
401              The first instance of this argument will rewrite both server and
402              client traffic, but if this argument is specified a second time,
403              it will be used for the client traffic.
404
405              Example:
406                  --user-dlink=01,02,03,04,05,06,00,1A,2B,3C,4D,5E,6F,08,00
407
408       -d number, --dbug=number
409              Enable debugging output.  This option may appear up to 1 times.
410              This option takes an integer number as its argument.  The value
411              of number is constrained to being:
412                  in the range  0 through 5
413              The default number for this option is:
414                   0
415
416              If configured with --enable-debug, then you can specify a ver‐
417              bosity level for debugging output.  Higher numbers increase ver‐
418              bosity.
419
420       -i string, --intf1=string
421              Primary interface (listen in uni-directional mode).  This option
422              may appear up to 1 times.
423
424
425       -I string, --intf2=string
426              Secondary interface (send in uni-directional mode).  This option
427              may appear up to 1 times.
428
429
430       -u, --unidir
431              Send and receive in only one direction.  This option may appear
432              up to 1 times.
433
434              Normally, tcpbridge will send and receive traffic in both direc‐
435              tions (bi-directionally).  However, if you choose this option,
436              traffic will be sent uni-directionally.
437
438       --listnics
439              List available network interfaces and exit.
440
441
442       -L number, --limit=number
443              Limit the number of packets to send.  This option may appear up
444              to 1 times.  This option takes an integer number as its argu‐
445              ment.  The value of number is constrained to being:
446                  greater than or equal to 1
447              The default number for this option is:
448                   -1
449
450              By default, tcpbridge will send packets forever or until Ctrl-C.
451              Alternatively, you can specify a maximum number of packets to
452              send.
453
454       -M string, --mac=string
455              MAC addresses of local NIC's.  This option may appear up to 2
456              times.
457
458              tcpbridge does not support detecting the MAC addresses of the
459              local network interfaces under Windows.  Please specify both MAC
460              addresses of the interfaces used in the bridge: -M <intf1 mac>
461              -M <intf2 mac>
462
463       -x string, --include=string
464              Include only packets matching rule.  This option may appear up
465              to 1 times.  This option must not appear in combination with any
466              of the following options: exclude.
467
468              Override default of sending all packets stored in the capture
469              file and only send packets which match the provided rule.  Rules
470              can be one of:
471
472
473              S:<CIDR1>,...  - Source IP must match specified CIDR(s)
474
475              D:<CIDR1>,...  - Destination IP must match specified CIDR(s)
476
477              B:<CIDR1>,...  - Both source and destination IP must match spec‐
478              ified CIDR(s)
479
480              E:<CIDR1>,...  - Either IP must match specified CIDR(s)
481
482              P:<LIST> - Must be one of the listed packets where the list cor‐
483              responds to the packet number in the capture file.
484                  --include=P:1-5,9,15,72-
485              would send packets 1 through 5, the 9th and 15th packet, and
486              packets 72 until the end of the file
487
488              F:'<bpf>' - BPF filter.  See the tcpdump(8) man page for syntax.
489
490       -X string, --exclude=string
491              Exclude any packet matching this rule.  This option may appear
492              up to 1 times.  This option must not appear in combination with
493              any of the following options: include.
494
495              Override default of sending all packets stored in the capture
496              file and only send packets which do not match the provided rule.
497              Rules can be one of:
498
499
500              S:<CIDR1>,...  - Source IP must not match specified CIDR(s)
501
502              D:<CIDR1>,...  - Destination IP must not match specified CIDR(s)
503
504              B:<CIDR1>,...  - Both source and destination IP must not match
505              specified CIDR(s)
506
507              E:<CIDR1>,...  - Either IP must not match specified CIDR(s)
508
509              P:<LIST> - Must not be one of the listed packets where the list
510              corresponds to the packet number in the capture file.
511                  --exclude=P:1-5,9,15,72-
512              would drop packets 1 through 5, the 9th and 15th packet, and
513              packets 72 until the end of the file
514
515       -P, --pid
516              Print the PID of tcpbridge at startup.
517
518
519       -v, --verbose
520              Print decoded packets via tcpdump to STDOUT.  This option may
521              appear up to 1 times.
522
523
524       -A string, --decode=string
525              Arguments passed to tcpdump decoder.  This option may appear up
526              to 1 times.  This option must appear in combination with the
527              following options: verbose.
528
529              When enabling verbose mode (-v) you may also specify one or more
530              additional  arguments to pass to tcpdump to modify the way pack‐
531              ets are decoded.  By default, -n and -l are used.   Be  sure  to
532              quote the arguments like: --verbose="-axxx" so that they are not
533              interpreted by tcpbridge.  The following arguments are valid:
534                  [ -aAeNqRStuvxX ]
535                  [ -E spi@ipaddr algo:secret,... ]
536                  [ -s snaplen ]
537
538       -V, --version
539              Print version information.
540
541
542       -h, --less-help
543              Display less usage information and exit.
544
545
546       -H, --help
547              Display usage information and exit.
548
549       -!, --more-help
550              Pass the extended usage information through a pager.
551
552       --save-opts [=cfgfile]
553              Save the option state to cfgfile.  The default is the last con‐
554              figuration file listed in the OPTION PRESETS section, below.
555              The command will exit after updating the config file.
556
557       --load-opts=cfgfile, --no-load-opts
558              Load options from cfgfile.  The no-load-opts form will disable
559              the loading of earlier config/rc/ini files.  --no-load-opts is
560              handled early, out of order.
561

OPTION PRESETS

563       Any option that is not marked as not presettable may be preset by load‐
564       ing values from configuration ("RC" or ".INI") file(s).  The homerc
565       file is "$$/", unless that is a directory.  In that case, the file
566       ".tcpbridgerc" is searched for within that directory.
567

FILES

569       See OPTION PRESETS for configuration files.
570

EXIT STATUS

572       One of the following exit values will be returned:
573
574       0  (EXIT_SUCCESS)
575              Successful program execution.
576
577       1  (EXIT_FAILURE)
578              The operation failed or the command syntax was not valid.
579
580       66  (EX_NOINPUT)
581              A specified configuration file could not be loaded.
582
583       70  (EX_SOFTWARE)
584              libopts had an internal operational error.  Please report it to
585              autogen-users@lists.sourceforge.net.  Thank you.
586

AUTHORS

588       Copyright 2013-2018 Fred Klassen - AppNeta Copyright 2000-2012 Aaron
589       Turner For support please use the tcpreplay-users@lists.sourceforge.net
590       mailing list.  The latest version of this software is always available
591       from: http://tcpreplay.appneta.com/
592
594       Copyright (C) 2000-2018 Aaron Turner and Fred Klassen all rights re‐
595       served.  This program is released under the terms of the GNU General
596       Public License, version 3 or later.
597

BUGS

599       Please send bug reports to: tcpreplay-users@lists.sourceforge.net
600

NOTES

602       This manual page was AutoGen-erated from the tcpbridge option defini‐
603       tions.
604
605
606
607tcpbridge                         01 May 2021                     tcpbridge(1)
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