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       igrp - igrp route injector


       igrp  -i  <interface>  -v  -f  <routes file> -a <as number> -S <spoofed
       source ip addrs> -D <destination router ip addrs>


       This manual page documents briefly the igrp command.  This manual  page
       was  written  for  the Debian distribution because the original program
       does not have a manual page.

       IGRP is a tool for route injection. The routing  protocol  IGRP  is  no
       longer  really  widely  used  in  the  outside world, but for the first
       steps, we decided to use this one as a starting point.

       The whole purpose is to  define  a  routing  table  with  all  possible
       parameters by hand without having your system actually running any kind
       of dynamic routing and sending this information  out  to  the  routers.
       Since  IGRP  is  a broadcast based protocol, the default behavior is to
       send these messages to the ip broadcast address  (  If
       you  want  to  inject  a route to a system remote from you, you have to
       address the ’update’ accordingly  and  make  sure  that  you  send  the
       packet(s)  with  the  right  source  address, so the router accepts the

       Before using the tool, you have to design your routing table  you  want
       to inject in the target router. It should contain data which makes your
       route the prefered one for the victim. The format is:


       where destination is the network  (,  delay  is  in  ms/10,
       bandwith in MBit per second, MTU is the maximum transfer unit (1500 for
       ethernet), reliability and load are in  percent  (255=100%,  1=0%)  and
       hopcount just in hops.

       Empty lines and lines beginning with # are ignored.

       -i <interface> interface

       -v verbose

       -f <routes file> file, which contains the routes  (as much as you like)

       -a <autonomous system> autonomous system the IGRP  process  is  running
       on,  use  ASS to find it out or specify a range to use with -a START -b
       STOP to send updates to all AS from START to STOP (I  highly  recommend
       using ASS for this!!)

       -S <spoofed source IP> maybe you need this

       -D <destination IP> If you don’t specify this, the broadcast address is

       If you want the routes to be persistent (after  some  testing  around),
       make  up  a shell loop and run the program within this loop every 25-30
       seconds, to keep the router beliving your routes.


       This manual page was written by Vince Mulhollon  <>,  for
       the Debian GNU/Linux system (but may be used by others).

                                January 1, 2003