NAME¶
tcpbridge - Bridge network traffic across two interfaces
SYNOPSIS¶
tcpbridge [
-flag [
value]]...
[
--opt-name [[=| ]
value]]...
All arguments must be options.
tcpbridge is a tool for selectively briding network traffic across two
interfaces and optionally modifying the packets in betweeen
DESCRIPTION¶
This manual page briefly documents the
tcpbridge command. The basic
operation of tcpbridge is to be a network bridge between two subnets. All
packets received on one interface are sent via the other.
Optionally, packets can be edited in a variety of ways according to your needs.
For more details, please see the Tcpreplay Manual at:
http://tcpreplay.synfin.net/trac/wiki/manual
OPTIONS¶
- -r string, --portmap=string
- Rewrite TCP/UDP ports. This option may appear up to -1 times.
Specify a list of comma delimited port mappingings consisting of colon
delimited port number pairs. Each colon delimited port pair consists of
the port to match followed by the port number to rewrite.
Examples:
--portmap=80:8000 --portmap=8080:80 # 80->8000 and 8080->80
--portmap=8000,8080,88888:80 # 3 different ports become 80
--portmap=8000-8999:80 # ports 8000 to 8999 become 80
- -s number, --seed=number
- Randomize src/dst IPv4/v6 addresses w/ given seed. This option may appear
up to 1 times. This option takes an integer number as its argument.
Causes the source and destination IPv4/v6 addresses to be pseudo randomized
but still maintain client/server relationships. Since the randomization is
deterministic based on the seed, you can reuse the same seed value to
recreate the traffic.
- -N string, --pnat=string
- Rewrite IPv4/v6 addresses using pseudo-NAT. This option may appear up to 2
times. This option must not appear in combination with any of the
following options: srcipmap.
Takes a comma delimited series of colon delimited CIDR netblock pairs. Each
netblock pair is evaluated in order against the IP addresses. If the IP
address in the packet matches the first netblock, it is rewriten using the
second netblock as a mask against the high order bits.
IPv4 Example:
--pnat=192.168.0.0/16:10.77.0.0/16,172.16.0.0/12:10.1.0.0/24
IPv6 Example:
--pnat=[2001:db8::/32]:[dead::/16],[2001:db8::/32]:[::ffff:0:0/96]
- -S string, --srcipmap=string
- Rewrite source IPv4/v6 addresses using pseudo-NAT. This option may appear
up to 1 times. This option must not appear in combination with any of the
following options: pnat.
Works just like the --pnat option, but only affects the source IP addresses
in the IPv4/v6 header.
- -D string, --dstipmap=string
- Rewrite destination IPv4/v6 addresses using pseudo-NAT. This option may
appear up to 1 times. This option must not appear in combination with any
of the following options: pnat.
Works just like the --pnat option, but only affects the destination IP
addresses in the IPv4/v6 header.
- -e string, --endpoints=string
- Rewrite IP addresses to be between two endpoints. This option may appear
up to 1 times. This option must appear in combination with the following
options: cachefile.
Takes a pair of colon delimited IPv4/v6 addresses which will be used to
rewrite all traffic to appear to be between the two IP's.
IPv4 Example:
--endpoints=172.16.0.1:172.16.0.2
IPv6 Example:
--endpoints=[2001:db8::dead:beef]:[::ffff:0:0:ac:f:0:2]
- -b, --skipbroadcast
- Skip rewriting broadcast/multicast IPv4/v6 addresses.
By default --seed, --pnat and --endpoints will rewrite broadcast and
multicast IPv4/v6 and MAC addresses. Setting this flag will keep
broadcast/multicast IPv4/v6 and MAC addresses from being rewritten.
- -C, --fixcsum
- Force recalculation of IPv4/TCP/UDP header checksums.
Causes each IPv4/v6 packet to have it's checksums recalcualted and fixed.
Automatically enabled for packets modified with --seed,
--pnat, --endpoints or --fixlen.
- -m number, --mtu=number
- Override default MTU length (1500 bytes). This option may appear up to 1
times. This option takes an integer number as its argument. The value of
number is constrained to being:
in the range 1 through MAXPACKET
Override the default 1500 byte MTU size for determining the maximum padding
length (--fixlen=pad) or when truncating (--mtu-trunc).
- --mtu-trunc
- Truncate packets larger then specified MTU. This option may appear up to 1
times.
Similar to --fixlen, this option will truncate data in packets from Layer 3
and above to be no larger then the MTU.
- -E, --efcs
- Remove Ethernet checksums (FCS) from end of frames.
Note, this option is pretty dangerous! We don't actually check to see if a
FCS actually exists in the frame, we just blindly delete the last two
bytes. Hence, you should only use this if you know know that your OS
provides the FCS when reading raw packets.
- --ttl=string
- Modify the IPv4/v6 TTL/Hop Limit.
Allows you to modify the TTL/Hop Limit of all the IPv4/v6 packets. Specify a
number to hard-code the value or +/-value to increase or decrease by the
value provided (limited to 1-255).
Examples:
--ttl=10
--ttl=+7
--ttl=-64
- --tos=number
- Set the IPv4 TOS/DiffServ/ECN byte. This option may appear up to 1 times.
This option takes an integer number as its argument. The value of
number is constrained to being:
in the range 0 through 255
Allows you to override the TOS (also known as DiffServ/ECN) value in
IPv4.
- --tclass=number
- Set the IPv6 Traffic Class byte. This option may appear up to 1 times.
This option takes an integer number as its argument. The value of
number is constrained to being:
in the range 0 through 255
Allows you to override the IPv6 Traffic Class field.
- --flowlabel=number
- Set the IPv6 Flow Label. This option may appear up to 1 times. This option
takes an integer number as its argument. The value of number is
constrained to being:
in the range 0 through 1048575
Allows you to override the 20bit IPv6 Flow Label field. Has no effect on
IPv4 packets.
- -F string, --fixlen=string
- Pad or truncate packet data to match header length. This option may appear
up to 1 times.
Packets may be truncated during capture if the snaplen is smaller then the
packet. This option allows you to modify the packet to pad the packet back
out to the size stored in the IPv4/v6 header or rewrite the IP header
total length to reflect the stored packet length.
pad Truncated packets will be padded out so that the packet length
matches the IPv4 total length
trunc Truncated packets will have their IPv4 total length field
rewritten to match the actual packet length
del Delete the packet
- --skipl2broadcast
- Skip rewriting broadcast/multicast Layer 2 addresses.
By default, editing Layer 2 addresses will rewrite broadcast and multicast
MAC addresses. Setting this flag will keep broadcast/multicast MAC
addresses from being rewritten.
- --dlt=string
- Override output DLT encapsulation. This option may appear up to 1 times.
By default, no DLT (data link type) conversion will be made. To change the
DLT type of the output pcap, select one of the following values:
enet Ethernet aka DLT_EN10MB
hdlc Cisco HDLC aka DLT_C_HDLC
user User specified Layer 2 header and DLT type
- --enet-dmac=string
- Override destination ethernet MAC addresses. This option may appear up to
1 times.
Takes a pair of comma deliminated ethernet MAC addresses which will replace
the destination MAC address of outbound packets. The first MAC address
will be used for the server to client traffic and the optional second MAC
address will be used for the client to server traffic.
Example:
--enet-dmac=00:12:13:14:15:16,00:22:33:44:55:66
- --enet-smac=string
- Override source ethernet MAC addresses. This option may appear up to 1
times.
Takes a pair of comma deliminated ethernet MAC addresses which will replace
the source MAC address of outbound packets. The first MAC address will be
used for the server to client traffic and the optional second MAC address
will be used for the client to server traffic.
Example:
--enet-smac=00:12:13:14:15:16,00:22:33:44:55:66
- --enet-vlan=string
- Specify ethernet 802.1q VLAN tag mode. This option may appear up to 1
times.
Allows you to rewrite ethernet frames to add a 802.1q header to standard
802.3 ethernet headers or remove the 802.1q VLAN tag information.
add Rewrites the existing 802.3 ethernet header as an 802.1q VLAN
header
del Rewrites the existing 802.1q VLAN header as an 802.3 ethernet
header
- --enet-vlan-tag=number
- Specify the new ethernet 802.1q VLAN tag value. This option may appear up
to 1 times. This option must appear in combination with the following
options: enet-vlan. This option takes an integer number as its argument.
The value of number is constrained to being:
in the range 0 through 4095
- --enet-vlan-cfi=number
- Specify the ethernet 802.1q VLAN CFI value. This option may appear up to 1
times. This option must appear in combination with the following options:
enet-vlan. This option takes an integer number as its argument. The value
of number is constrained to being:
in the range 0 through 1
- --enet-vlan-pri=number
- Specify the ethernet 802.1q VLAN priority. This option may appear up to 1
times. This option must appear in combination with the following options:
enet-vlan. This option takes an integer number as its argument. The value
of number is constrained to being:
in the range 0 through 7
- --hdlc-control=number
- Specify HDLC control value. This option may appear up to 1 times. This
option takes an integer number as its argument.
The Cisco HDLC header has a 1 byte "control" field. Apparently
this should always be 0, but if you can use any 1 byte value.
- --hdlc-address=number
- Specify HDLC address. This option may appear up to 1 times. This option
takes an integer number as its argument.
The Cisco HDLC header has a 1 byte "address" field which has two
valid values:
0x0F Unicast
0xBF Broadcast
You can however specify any single byte value.
- --user-dlt=number
- Set output file DLT type. This option may appear up to 1 times. This
option takes an integer number as its argument.
Set the DLT value of the output pcap file.
- --user-dlink=string
- Rewrite Data-Link layer with user specified data. This option may appear
up to 2 times.
Provide a series of comma deliminated hex values which will be used to
rewrite or create the Layer 2 header of the packets. The first instance of
this argument will rewrite both server and client traffic, but if this
argument is specified a second time, it will be used for the client
traffic.
Example:
--user-dlink=01,02,03,04,05,06,00,1A,2B,3C,4D,5E,6F,08,00
- -d number, --dbug=number
- Enable debugging output. This option may appear up to 1 times. This option
takes an integer number as its argument. The value of number is
constrained to being:
in the range 0 through 5
The default number for this option is:
0
If configured with --enable-debug, then you can specify a verbosity level
for debugging output. Higher numbers increase verbosity.
- -i string, --intf1=string
- Primary interface (listen in uni-directional mode). This option may appear
up to 1 times.
- -I string, --intf2=string
- Secondary interface (send in uni-directional mode). This option may appear
up to 1 times.
- -u, --unidir
- Send and receive in only one direction. This option may appear up to 1
times.
Normally, tcpbridge will send and receive traffic in both directions
(bi-directionally). However, if you choose this option, traffic will be
sent uni-directionally.
- --listnics
- List available network interfaces and exit.
- -L number, --limit=number
- Limit the number of packets to send. This option may appear up to 1 times.
This option takes an integer number as its argument. The value of
number is constrained to being:
greater than or equal to 1
The default number for this option is:
-1
By default, tcpbridge will send packets forever or until Ctrl-C.
Alternatively, you can specify a maximum number of packets to send.
- -M string, --mac=string
- MAC addresses of local NIC's. This option may appear up to 2 times.
tcpbridge does not support detecting the MAC addresses of the local network
interfaces under Windows. Please specify both MAC addresses of the
interfaces used in the bridge: -M <intf1 mac> -M <intf2
mac>
- -x string, --include=string
- Include only packets matching rule. This option may appear up to 1 times.
This option must not appear in combination with any of the following
options: exclude.
Override default of sending all packets stored in the capture file and only
send packets which match the provided rule. Rules can be one of:
S:<CIDR1>,... - Source IP must match specified CIDR(s)
D:<CIDR1>,... - Destination IP must match specified CIDR(s)
B:<CIDR1>,... - Both source and destination IP must match
specified CIDR(s)
E:<CIDR1>,... - Either IP must match specified CIDR(s)
P:<LIST> - Must be one of the listed packets where the list
corresponds to the packet number in the capture file.
--include=P:1-5,9,15,72-
would send packets 1 thru 5, the 9th and 15th packet, and packets 72 until
the end of the file
F:'<bpf>' - BPF filter. See the tcpdump(8) man page for
syntax.
- -X string, --exclude=string
- Exclude any packet matching this rule. This option may appear up to 1
times. This option must not appear in combination with any of the
following options: include.
Override default of sending all packets stored in the capture file and only
send packets which do not match the provided rule. Rules can be one of:
S:<CIDR1>,... - Source IP must not match specified CIDR(s)
D:<CIDR1>,... - Destination IP must not match specified CIDR(s)
B:<CIDR1>,... - Both source and destination IP must not match
specified CIDR(s)
E:<CIDR1>,... - Either IP must not match specified CIDR(s)
P:<LIST> - Must not be one of the listed packets where the list
corresponds to the packet number in the capture file.
--exclude=P:1-5,9,15,72-
would drop packets 1 thru 5, the 9th and 15th packet, and packets 72 until
the end of the file
- -P, --pid
- Print the PID of tcpbridge at startup.
- -v, --verbose
- Print decoded packets via tcpdump to STDOUT. This option may appear up to
1 times.
- -A string, --decode=string
- Arguments passed to tcpdump decoder. This option may appear up to 1 times.
This option must appear in combination with the following options:
verbose.
When enabling verbose mode ( -v) you may also specify one or more
additional arguments to pass to tcpdump to modify the way packets
are decoded. By default, -n and -l are used. Be sure to quote the
arguments like: --verbose="-axxx" so that they are not
interpreted by tcpbridge. The following arguments are vaild:
[ -aAeNqRStuvxX ]
[ -E spi@ipaddr algo:secret,... ]
[ -s snaplen ]
- -V, --version
- Print version information.
- -h, --less-help
- Display less usage information and exit.
- -H, --help
- Display usage information and exit.
- -!, --more-help
- Extended usage information passed thru pager.
- - [rcfile], --save-opts[=rcfile]
- Save the option state to rcfile. The default is the last
configuration file listed in the OPTION PRESETS section,
below.
- - rcfile, --load-opts=rcfile,
--no-load-opts
- Load options from rcfile. The no-load-opts form will disable
the loading of earlier RC/INI files. --no-load-opts is handled
early, out of order.
OPTION PRESETS¶
Any option that is not marked as
not presettable may be preset by loading
values from configuration ("RC" or ".INI") file(s). The
homerc file is "
$$/", unless that is a directory. In
that case, the file "
.tcpbridgerc" is searched for within
that directory.
SIGNALS¶
tcpbridge understands the following signals:
SIGUSR1 Suspend tcpbridge
SIGCONT Restart tcpbridge
SEE ALSO¶
tcpdump(1),
tcpprep(1),
tcprewrite(1),
tcpreplay(1)
BUGS¶
tcpbridge can only send packets as fast as your computer's interface, processor
and system bus will allow.
Connecting both interfaces to the same subnet may create a broadcast storm and
take down the network. Improper use of the packet editing functions may have
other undefined and possible negative consequences.
Some operating systems by default do not allow for forging source MAC addresses.
Please consult your operating system's documentation and the tcpreplay FAQ if
you experiance this issue.
AUTHOR¶
Copyright 2000-2010 Aaron Turner
For support please use the tcpreplay-users@lists.sourceforge.net mailing list.
The latest version of this software is always available from:
http://tcpreplay.synfin.net/
Released under the Free BSD License.
This manual page was
AutoGen-erated from the
tcpbridge option
definitions.