1TCPBRIDGE(1) Programmer's Manual TCPBRIDGE(1)
2
6 tcpbridge - Bridge network traffic across two interfaces
7
9 tcpbridge [-flag [value]]... [--opt-name [[=| ]value]]...
10 All arguments must be options.
12 tcpbridge is a tool for selectively briding network traffic across two
14 interfaces and optionally modifying the packets in betweeen
15
17 This manual page documents, briefly, the tcpbridge command. The basic
18 operation of tcpbridge is to be a network bridge between two subnets.
19 All packets received on one interface are sent via the other.
20 Optionally, packets can be edited in a variety of ways according to
22 your needs.
23 For more details, please see the Tcpreplay Manual at: http://tcpre‐
25 play.synfin.net/trac/wiki/manual
26
28 -r string, --portmap=string
30 Rewrite TCP/UDP ports. This option may appear up to 1 times.
31 Specify a list of comma delimited port mappingings consisting of
33 colon delimited port number pairs. Each colon delimited port
34 pair consists of the port to match followed by the port number
35 to rewrite.
36 Example:
38 --portmap=80:8000,8080:80
39 -s number, --seed=number
41 Randomize src/dst IP addresses w/ given seed. This option may
42 appear up to 1 times. This option takes an integer number as
43 its argument.
44 Causes the source and destination IP addresses to be pseudo ran‐
46 domized but still maintain client/server relationships. Since
47 the randomization is deterministic based on the seed, you can
48 reuse the same seed value to recreate the traffic.
49 -N string, --pnat=string
51 Rewrite IP addresses using pseudo-NAT. This option may appear
52 up to 2 times. This option must not appear in combination with
53 any of the following options: srcipmap.
54 Takes a comma delimited series of colon delimited CIDR netblock
56 pairs. Each netblock pair is evaluated in order against the IP
57 addresses. If the IP address in the packet matches the first
58 netblock, it is rewriten using the second netblock as a mask
59 against the high order bits.
60 Example:
62 --pnat=192.168.0.0/16:10.77.0.0/16,172.16.0.0/12:10.1.0.0/24
63 -S string, --srcipmap=string
65 Rewrite source IP addresses using pseudo-NAT. This option may
66 appear up to 1 times. This option must not appear in combina‐
67 tion with any of the following options: pnat.
68 Works just like the --pnat option, but only affects the source
70 IP addresses in the IPv4 header.
71 -D string, --dstipmap=string
73 Rewrite destination IP addresses using pseudo-NAT. This option
74 may appear up to 1 times. This option must not appear in combi‐
75 nation with any of the following options: pnat.
76 Works just like the --pnat option, but only affects the destina‐
78 tion IP addresses in the IPv4 header.
79 -e string, --endpoints=string
81 Rewrite IP addresses to be between two endpoints. This option
82 may appear up to 1 times. This option must appear in combina‐
83 tion with the following options: cachefile.
84 Takes a pair of colon delimited IP addresses which will be used
86 to rewrite all traffic to appear to be between the two IP's.
87 Example:
89 --endpoints=172.16.0.1:172.16.0.2
90 -b, --skipbroadcast
92 Skip rewriting broadcast/multicast IP's.
93 By default --seed, --pnat and --endpoints will rewrite broadcast
95 and multicast IP and MAC addresses. Setting this flag will keep
96 broadcast/multicast IP and MAC addresses from being rewritten.
97 -C, --fixcsum
99 Force recalculation of IP/TCP/UDP checksums.
100 Causes each IP packet to have it's checksums recalcualted and
102 fixed. Automatically enabled for packets modified with --seed,
103 --pnat, --endpoints or --fixlen.
104 -m number, --mtu=number
106 Override default MTU length (1500 bytes). This option may
107 appear up to 1 times. This option takes an integer number as
108 its argument. The value of number is constrained to being:
109 in the range 1 through MAXPACKET
110 Override the default 1500 byte MTU size for determining the max‐
112 imum padding length.
113 -E, --efcs
115 Remove Ethernet checksums (FCS) from end of frames.
116 Note, this option is pretty dangerous! We don't actually check
118 to see if a FCS actually exists in the frame, we just blindly
119 delete the last two bytes. Hence, you should only use this if
120 you know know that your OS provides the FCS when reading raw
121 packets.
122 --ttl=string
124 Modify the IPv4 TTL.
125 Allows you to modify the TTL of all the IPv4 packets. Specify a
127 number to hard-code the value or +/-value to increase or
128 decrease by the value provided (limited to 1-255).
129 Examples:
131 --ttl=10
132 --ttl=+7
133 --ttl=-64
134 -F string, --fixlen=string
136 Pad or truncate packet data to match header length. This option
137 may appear up to 1 times.
138 Packets may be truncated during capture if the snaplen is
140 smaller then the packet. This option allows you to modify the
141 packet to pad the packet back out to the size stored in the IPv4
142 header or rewrite the IP header total length to reflect the
143 stored packet length.
144 pad Truncated packets will be padded out so that the packet
146 length matches the IPv4 total length
147 trunc Truncated packets will have their IPv4 total length field
149 rewritten to match the actual packet length
150 del Delete the packet
152 --skipl2broadcast
154 Skip rewriting broadcast/multicast Layer 2 addresses.
155 By default, editing Layer 2 addresses will rewrite broadcast and
157 multicast MAC addresses. Setting this flag will keep broad‐
158 cast/multicast MAC addresses from being rewritten.
159 --dlt=string
161 Override output DLT encapsulation. This option may appear up to
162 1 times.
163 By default, no DLT (data link type) conversion will be made. To
165 change the DLT type of the output pcap, select one of the fol‐
166 lowing values:
167 enet Ethernet aka DLT_EN10MB
169 hdlc Cisco HDLC aka DLT_C_HDLC
171 user User specified Layer 2 header and DLT type
173 --enet-dmac=string
175 Override destination ethernet MAC addresses. This option may
176 appear up to 1 times.
177 Takes a pair of comma deliminated ethernet MAC addresses which
179 will replace the destination MAC address of outbound packets.
180 The first MAC address will be used for the server to client
181 traffic and the optional second MAC address will be used for the
182 client to server traffic.
183 Example:
185 --enet-dmac=00:12:13:14:15:16,00:22:33:44:55:66
186 --enet-smac=string
188 Override source ethernet MAC addresses. This option may appear
189 up to 1 times.
190 Takes a pair of comma deliminated ethernet MAC addresses which
192 will replace the source MAC address of outbound packets. The
193 first MAC address will be used for the server to client traffic
194 and the optional second MAC address will be used for the client
195 to server traffic.
196 Example:
198 --enet-smac=00:12:13:14:15:16,00:22:33:44:55:66
199 --enet-vlan=string
201 Specify ethernet 802.1q VLAN tag mode. This option may appear
202 up to 1 times.
203 Allows you to rewrite ethernet frames to add a 802.1q header to
205 standard 802.3 ethernet headers or remove the 802.1q VLAN tag
206 information.
207 add Rewrites the existing 802.3 ethernet header as an 802.1q
209 VLAN header
210 del Rewrites the existing 802.1q VLAN header as an 802.3 ether‐
212 net header
213 --enet-vlan-tag=number
215 Specify the new ethernet 802.1q VLAN tag value. This option may
216 appear up to 1 times. This option must appear in combination
217 with the following options: enet-vlan. This option takes an
218 integer number as its argument. The value of number is con‐
219 strained to being:
220 in the range 0 through 4095
221 --enet-vlan-cfi=number
225 Specify the ethernet 802.1q VLAN CFI value. This option may
226 appear up to 1 times. This option must appear in combination
227 with the following options: enet-vlan. This option takes an
228 integer number as its argument. The value of number is con‐
229 strained to being:
230 in the range 0 through 1
231 --enet-vlan-pri=number
235 Specify the ethernet 802.1q VLAN priority. This option may
236 appear up to 1 times. This option must appear in combination
237 with the following options: enet-vlan. This option takes an
238 integer number as its argument. The value of number is con‐
239 strained to being:
240 in the range 0 through 7
241 --hdlc-control=number
245 Specify HDLC control value. This option may appear up to 1
246 times. This option takes an integer number as its argument.
247 The Cisco HDLC header has a 1 byte "control" field. Apparently
249 this should always be 0, but if you can use any 1 byte value.
250 --hdlc-address=number
252 Specify HDLC address. This option may appear up to 1 times.
253 This option takes an integer number as its argument.
254 The Cisco HDLC header has a 1 byte "address" field which has two
256 valid values:
257 0x0F Unicast
259 0xBF Broadcast
261 You can however specify any single byte value.
262 --user-dlt=number
264 Set output file DLT type. This option may appear up to 1 times.
265 This option takes an integer number as its argument.
266 Set the DLT value of the output pcap file.
268 --user-dlink=string
270 Rewrite Data-Link layer with user specified data. This option
271 may appear up to 2 times.
272 Provide a series of comma deliminated hex values which will be
274 used to rewrite or create the Layer 2 header of the packets.
275 The first instance of this argument will rewrite both server and
276 client traffic, but if this argument is specified a second time,
277 it will be used for the client traffic.
278 Example:
280 --user-dlink=01,02,03,04,05,06,00,1A,2B,3C,4D,5E,6F,08,00
281 -d number, --dbug=number
283 Enable debugging output. This option may appear up to 1 times.
284 This option takes an integer number as its argument. The value
285 of number is constrained to being:
286 in the range 0 through 5
287 The default number for this option is:
288 0
289 If configured with --enable-debug, then you can specify a ver‐
291 bosity level for debugging output. Higher numbers increase ver‐
292 bosity.
293 -i string, --intf1=string
295 Primary interface (listen in uni-directional mode). This option
296 may appear up to 1 times.
297 -I string, --intf2=string
301 Secondary interface (send in uni-directional mode). This option
302 may appear up to 1 times.
303 -u, --unidir
307 Send and receive in only one direction. This option may appear
308 up to 1 times.
309 Normally, tcpbridge will send and receive traffic in both direc‐
311 tions (bi-directionally). However, if you choose this option,
312 traffic will be sent uni-directionally.
313 -L number, --limit=number
315 Limit the number of packets to send. This option may appear up
316 to 1 times. This option takes an integer number as its argu‐
317 ment. The value of number is constrained to being:
318 greater than or equal to 1
319 The default number for this option is:
320 -1
321 By default, tcpbridge will send packets forever or until Ctrl-C.
323 Alternatively, you can specify a maximum number of packets to
324 send.
325 -x string, --include=string
327 Include only packets matching rule. This option may appear up
328 to 1 times. This option must not appear in combination with any
329 of the following options: exclude.
330 Override default of sending all packets stored in the capture
332 file and only send packets which match the provided rule. Rules
333 can be one of:
334 S:<CIDR1>,... - Source IP must match specified CIDR(s)
337 D:<CIDR1>,... - Destination IP must match specified CIDR(s)
339 B:<CIDR1>,... - Both source and destination IP must match spec‐
341 ified CIDR(s)
342 E:<CIDR1>,... - Either IP must match specified CIDR(s)
344 P:<LIST> - Must be one of the listed packets where the list cor‐
346 responds to the packet number in the capture file.
347 --include=P:1-5,9,15,72-
348 would send packets 1 thru 5, the 9th and 15th packet, and pack‐
349 ets 72 until the end of the file
350 F:'<bpf>' - BPF filter. See the tcpdump(8) man page for syntax.
352 -X string, --exclude=string
354 Exclude any packet matching this rule. This option may appear
355 up to 1 times. This option must not appear in combination with
356 any of the following options: include.
357 Override default of sending all packets stored in the capture
359 file and only send packets which do not match the provided rule.
360 Rules can be one of:
361 S:<CIDR1>,... - Source IP must not match specified CIDR(s)
364 D:<CIDR1>,... - Destination IP must not match specified CIDR(s)
366 B:<CIDR1>,... - Both source and destination IP must not match
368 specified CIDR(s)
369 E:<CIDR1>,... - Either IP must not match specified CIDR(s)
371 P:<LIST> - Must not be one of the listed packets where the list
373 corresponds to the packet number in the capture file.
374 --exclude=P:1-5,9,15,72-
375 would drop packets 1 thru 5, the 9th and 15th packet, and pack‐
376 ets 72 until the end of the file
377 -P, --pid
379 Print the PID of tcpbridge at startup.
380 -v, --verbose
384 Print decoded packets via tcpdump to STDOUT. This option may
385 appear up to 1 times.
386 -A string, --decode=string
390 Arguments passed to tcpdump decoder. This option may appear up
391 to 1 times. This option must appear in combination with the
392 following options: verbose.
393 When enabling verbose mode (-v) you may also specify one or more
395 additional arguments to pass to tcpdump to modify the way pack‐
396 ets are decoded. By default, -n and -l are used. Be sure to
397 quote the arguments like: --verbose="-axxx" so that they are not
398 interpreted by tcpbridge. The following arguments are vaild:
399 [ -aAeNqRStuvxX ]
400 [ -E spi@ipaddr algo:secret,... ]
401 [ -s snaplen ]
402 -V, --version
404 Print version information.
405 -h, --less-help
409 Display less usage information and exit.
410 -H, --help
414 Display usage information and exit.
415 -!, --more-help
417 Extended usage information passed thru pager.
418 - [rcfile], --save-opts[=rcfile]
420 Save the option state to rcfile. The default is the last con‐
421 figuration file listed in the OPTION PRESETS section, below.
422 - rcfile, --load-opts=rcfile, --no-load-opts
424 Load options from rcfile. The no-load-opts form will disable
425 the loading of earlier RC/INI files. --no-load-opts is handled
426 early, out of order.
427
429 Any option that is not marked as not presettable may be preset by load‐
430 ing values from configuration ("RC" or ".INI") file(s). The homerc
431 file is "$$/", unless that is a directory. In that case, the file
432 ".tcpbridgerc" is searched for within that directory.
433
435 tcpbridge understands the following signals:
436 SIGUSR1 Suspend tcpbridge
438 SIGCONT Restart tcpbridge
440
443 tcpdump(1), tcpprep(1), tcprewrite(1), tcpreplay(1)
444
447 tcpbridge can only send packets as fast as your computer's interface,
448 processor and system bus will allow.
449 Connecting both interfaces to the same subnet may create a broadcast
451 storm and take down the network. Improper use of the packet editing
452 functions may have other undefined and possible negative consequences.
453 Some operating systems by default do not allow for forging source MAC
455 addresses. Please consult your operating system's documentation and
456 the tcpreplay FAQ if you experiance this issue.
457
459 Copyright 2000-2008 Aaron Turner
460 For support please use the tcpreplay-users@lists.sourceforge.net mail‐
462 ing list.
463 The latest version of this software is always available from:
465 http://tcpreplay.synfin.net/
466 Released under the Free BSD License.
468 This manual page was AutoGen-erated from the tcpbridge option defini‐
470 tions.
471(tcpbridge ) 2008-05-15 TCPBRIDGE(1)