FreeBSD 7.0 manual page repository

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ipresend - resend IP packets out to network



        ipresend - resend IP packets out to network


        ipresend  [  -EHPRSTX ] [ -d <device> ] [ -g <gateway> ] [ -m <MTU> ] [
        -r <filename> ]


        ipresend was designed to allow packets to  be  resent,  once  captured,
        back out onto the network for use in testing.  ipresend supports a num‐
        ber of different file formats as input, including  saved  snoop/tcpdump
        binary data.


        -d <interface>
               Set  the interface name to be the name supplied.  This is useful
               with the -P, -S, -T and -E options, where it  is  not  otherwise
               possible  to associate a packet with an interface.  Normal "text
               packets" can override this setting.
        -g <gateway>
               Specify the hostname of the gateway through which to route pack‐
               ets.   This  is  required  whenever  the  destination host isn’t
               directly attached to the same network as  the  host  from  which
               you’re sending.
        -m <MTU>
               Specify  the  MTU  to  be  used  when sending out packets.  This
               option allows you to set a fake MTU, allowing the simulation  of
               network interfaces with small MTU’s without setting them so.
        -r <filename>
               Specify  the  filename  from  which  to  take input.  Default is
        -E     The input file is to be text output from  etherfind.   The  text
               formats  which  are  currently  supported are those which result
               from the following etherfind option combinations:
                  etherfind -n
                  etherfind -n -t
        -H     The input file is to be  hex  digits,  representing  the  binary
               makeup  of  the  packet.   No  length  correction is made, if an
               incorrect length is put in the IP header.
        -P     The input file specified by -i is a binary file  produced  using
               libpcap  (i.e.,  tcpdump version 3).  Packets are read from this
               file as being input (for rule purposes).
        -R     When sending packets out, send them out "raw" (the way they came
               in).  The only real significance here is that it will expect the
               link layer (i.e.  ethernet) headers to be prepended  to  the  IP
               packet being output.
        -S     The input file is to be in "snoop" format (see RFC 1761).  Pack‐
               ets are read from this file and used as input  from  any  inter‐
               face.  This is perhaps the most useful input type, currently.
        -T     The input file is to be text output from tcpdump.  The text for‐
               mats which are currently supported are those which  result  from
               the following tcpdump option combinations:
                  tcpdump -n
                  tcpdump -nq
                  tcpdump -nqt
                  tcpdump -nqtt
                  tcpdump -nqte
        -X     The input file is composed of text descriptions of IP packets.
        snoop(1m),    tcpdump(8),   etherfind(8c),   ipftest(1),   ipresend(1),
        iptest(1), bpf(4), dlpi(7p)


        Needs to be run as root.


        Not all of the input formats are sufficiently capable of introducing  a
        wide  enough  variety  of packets for them to be all useful in testing.
        If you find any, please send email to me at


Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.