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tcprewrite(1)			 User Commands			 tcprewrite(1)

NAME
       tcprewrite - Rewrite the	packets	in a pcap file.

SYNOPSIS
       tcprewrite [-flags] [-flag [value]] [--option-name[[=| ]value]]

       All arguments must be options.

DESCRIPTION
       Tcprewrite  is a	tool to	rewrite	packets	stored in pcap(3) file format,
       such as created by tools	such as	tcpdump(1) and wireshark(1).   Once  a
       pcap file has had it's packets rewritten, they can be replayed back out
       on the network using tcpreplay(1).

       tcprewrite currently supports reading the following DLT types:

       DLT_C_HDLC aka Cisco HDLC

       DLT_EN10MB aka Ethernet

       DLT_LINUX_SLL aka Linux Cooked Socket

       DLT_RAW aka RAW IP

       DLT_NULL	aka BSD	Loopback

       DLT_LOOP	aka OpenBSD Loopback

       DLT_IEEE802_11 aka 802.11a/b/g

       DLT_IEEE802_11_RADIO aka	802.11a/b/g with Radiotap headers

       DLT_JUNIPER_ETHER aka Juniper Encapsulated Ethernet

       DLT_PPP_SERIAL aka PPP over Serial

       Please see the --dlt option for supported DLT types for writing.

       The packet editing features of  tcprewrite  which  distinguish  between
       "client"	and "server" traffic requires a	tcpprep(1) cache file.

       For  more  details,  please  see	the Tcpreplay Manual at: http://tcpre-
       play.appneta.com

OPTIONS

       -r string, --portmap=string
	      Rewrite TCP/UDP ports.  This option may appear up	to 9999	times.

	      Specify a	list of	comma delimited	port  mappings	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 must not appear in	combi-
	      nation  with  any	of the following options: fuzz-seed.  This op-
	      tion 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 ap-
	      pear 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 rewritten	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	combi-
	      nation 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 destina-
	      tion 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  combina-
	      tion 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
	      addresses.

	      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]

       --tcp-sequence=number
	      Change  TCP  Sequence (and ACK) numbers /w given seed.  This op-
	      tion takes an integer number as its argument.  The value of num-
	      ber is constrained to being:
		  greater than or equal	to 1
	      The default number for this option is:
		   0

	      Change all TCP sequence numbers, and related sequence-acknowl-
	      edgement numbers.	 They will be shifted by a random amount based
	      on the provided seed.

       -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 their checksums recalculated
	      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 ap-
	      pear 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 MAX_SNAPLEN

	      Override the default 1500	byte MTU size for determining the max-
	      imum padding length (--fixlen=pad) or when truncating (--mtu-
	      trunc).

       --mtu-trunc
	      Truncate packets larger then specified MTU.  This	option may ap-
	      pear 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 do not	actually check
	      to see if	a FCS actually exists in the frame, we just blindly
	      delete the last 4	bytes.	Hence, you should only use this	if you
	      know know	that your OS provides the FCS when reading raw pack-
	      ets.

       --ttl=string
	      Modify the IPv4/v6 TTL/Hop Limit.

	      Allows you to modify the TTL/Hop Limit of	all the	IPv4/v6	pack-
	      ets.  Specify a number to	hard-code the value or +/-value	to in-
	      crease 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 argu-
	      ment.  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

       --fuzz-seed=number
	      Fuzz 1 in	X packets. Edit	bytes, length, or emulate packet drop.
	      This option takes	an integer number as its argument.  The	value
	      of number	is constrained to being:
		  greater than or equal	to 0
	      The default number for this option is:
		   0

	      This fuzzing was designed	as to test layer 7 protocols such as
	      voip protocols.  It modifies randomly 1 out of X packets (where
	      X	= --fuzz-factor) in order for stateful protocols to cover more
	      of their code.  The random fuzzing actions focus on data start
	      and end because it often is the part of the data application
	      protocols	base their decisions on.

	      Possible fuzzing actions list:
	       * drop packet
	       * reduce	packet size
	       * edit packet Bytes:
		 * Not all Bytes have the same probability of appearance in
	      real life.
		   Replace with	0x00, 0xFF, or a random	byte with equal	like-
	      lihood.
		 * Not all Bytes have the same significance in a packet.
		   Replace the start, the end, or the middle of	the packet
	      with equal likelihood.
	       * do nothing (7 out of 8	packets)

       --fuzz-factor=number
	      Set the Fuzz 1 in	X packet ratio (default	1 in 8 packets).  This
	      option must appear in combination	with the following options:
	      fuzz-seed.  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:
		   8

	      Sets the ratio of	for --fuzz-seed	option.	By default this	value
	      is 8, which means	1 in 8 packets are modified by fuzzing.	Note
	      that this	ratio is based on the random number generated by the
	      supplied fuzz seed. Therefore by default you cannot expect that
	      exactly every eighth packet will be modified.

       --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 broad-
	      cast/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	fol-
	      lowing values:

	      enet Ethernet aka	DLT_EN10MB

	      hdlc Cisco HDLC aka DLT_C_HDLC

	      jnpr_ether Juniper Ethernet DLT_C_JNPR_ETHER

	      pppserial	PPP Serial aka DLT_PPP_SERIAL

	      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-subsmac=string
	      Substitute MAC addresses.	 This option may appear	up to 9999
	      times.

	      Allows you to rewrite ethernet MAC addresses of packets. It
	      takes comma delimited pair or MACs address and rewrites all oc-
	      currences	of the first MAC with the value	of the second MAC.
	      Example:
		  --enet-subsmac=00:12:13:14:15:16,00:22:33:44:55:66

       --enet-mac-seed=number
	      Randomize	MAC addresses.	This option may	appear up to 1 times.
	      This option must not appear in combination with any of the fol-
	      lowing options: enet-smac, enet-dmac, enet-subsmac.  This	option
	      takes an integer number as its argument.

	      Allows you to randomize ethernet MAC addresses of	packets,
	      mostly like what --seed option does for IPv4/IPv6	addresses.

       --enet-mac-seed-keep-bytes=number
	      Randomize	MAC addresses.	This option may	appear up to 1 times.
	      This option must appear in combination with the following	op-
	      tions: enet-mac-seed.  This option takes an integer number as
	      its argument.  The value of number is constrained	to being:
		  in the range	1 through 6

	      Keep some	bytes untouched	when usinging --enet-mac-seed option.

       --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 ether-
	      net 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 in-
	      teger number as its argument.  The value of number is con-
	      strained to being:
		  in the range	0 through 4095

       --enet-vlan-cfi=number
	      Specify the ethernet 802.1q VLAN CFI value.  This	option may ap-
	      pear 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 ap-
	      pear 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	ver-
	      bosity level for debugging output.  Higher numbers increase ver-
	      bosity.

       -i string, --infile=string
	      Input pcap file to be processed.	This option may	appear up to 1
	      times.

       -o string, --outfile=string
	      Output pcap file.	 This option may appear	up to 1	times.

       -c string, --cachefile=string
	      Split traffic via	tcpprep	cache file.  This option may appear up
	      to 1 times.

	      Use tcpprep cache	file to	split traffic based upon client/server
	      relationships.

       -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	pack-
	      ets are decoded.	By default, -n and -l are used.	 Be sure to
	      quote the	arguments so that they are not interpreted by
	      tcprewrite.   Please see the tcpdump(1) man page for a complete
	      list of options.

       --fragroute=string
	      Parse fragroute configuration file.  This	option may appear up
	      to 1 times.

	      Enable advanced evasion techniques using the built-in fra-
	      groute(8)	engine.	 See the fragroute(8) man page for more	de-
	      tails.  Important: tcprewrite does not support the delay,	echo
	      or print commands.

       --fragdir=string
	      Which flows to apply fragroute to: c2s, s2c, both.  This option
	      may appear up to 1 times.	 This option must appear in combina-
	      tion with	the following options: cachefile.

	      Apply the	fragroute engine to packets going c2s, s2c or both
	      when using a cache file.

       --skip-soft-errors
	      Skip writing packets with	soft errors.  This option may appear
	      up to 1 times.

	      In some cases, packets can not be	decoded	or the requested edit-
	      ing is not possible.  Normally these packets are written to the
	      output file unedited so that tcpprep cache files can still be
	      used, but	if you wish, these packets can be suppressed.

	      One example of this is 802.11 management frames which contain no
	      data.

       -V, --version
	      Print version information.

       -h, --less-help
	      Display less usage information and exit.

       -H, --help
	      Display usage information	and exit.

       -!, --more-help
	      Pass the extended	usage information through a pager.

       --save-opts [=cfgfile]
	      Save the option state to cfgfile.	 The default is	the last con-
	      figuration file listed in	the OPTION PRESETS section, below.
	      The command will exit after updating the config file.

       --load-opts=cfgfile, --no-load-opts
	      Load options from	cfgfile.  The no-load-opts form	will disable
	      the loading of earlier config/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 load-
       ing values from configuration ("RC" or ".INI") file(s).	The homerc
       file is "$$/", unless that is a directory.  In that case, the file
       ".tcprewriterc" is searched for within that directory.

FILES
       See OPTION PRESETS for configuration files.

EXIT STATUS
       One of the following exit values	will be	returned:

       0  (EXIT_SUCCESS)
	      Successful program execution.

       1  (EXIT_FAILURE)
	      The operation failed or the command syntax was not valid.

       66  (EX_NOINPUT)
	      A	specified configuration	file could not be loaded.

       70  (EX_SOFTWARE)
	      libopts had an internal operational error.  Please report	it to
	      autogen-users@lists.sourceforge.net.  Thank you.

AUTHORS
       Copyright 2013-2018 Fred	Klassen	- AppNeta Copyright 2000-2012 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.appneta.com/

COPYRIGHT
       Copyright (C) 2000-2018 Aaron Turner and	Fred Klassen all rights	re-
       served.	This program is	released under the terms of the	GNU General
       Public License, version 3 or later.

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

NOTES
       This manual page	was AutoGen-erated from	the tcprewrite option defini-
       tions.

tcprewrite			  01 Mar 2021			 tcprewrite(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPTION PRESETS | FILES | EXIT STATUS | AUTHORS | COPYRIGHT | BUGS | NOTES

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