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       icmpinfo - interpret ICMP messages


       icmpinfo [-v[v[v]]] [-n] [-p] [-s] [-l] [-k]


       Icmpinfo  is  a  tool  for looking at the ICMP messages received on the
       running host.  It can be used to detect and record ’bombs’ as  well  as
       various network problems.

       The output format is as follows (all on one line):

         MMM DD HH:MM:SS ICMP_type[sub-type]
            < sender_ip [sender_name] > unreach_ip [unreach_name]
            sp=source_port dp=dest_port seq=sequence sz=packet_size

       In  normal  operation,  icmpinfo  will  only report on "weird" packets,
       mainly icmp_unreachable.


       -v     Give information about all icmp packets, excepts pings.

       -vv    Give about pings too (i.e. icmp_echo_reply).

       -vvv   Include an ascii/hex dump of each packet

       -n     Avoid name queries - just give IP addresses.  (use  this  option
              when  running unattended on name server hosts (to avoid possible

       -p     Avoid port number to service name decoding.

       -s     Show the interface ip that received the packet. Useful  only  if
              your  host  has  several  network interfaces. In this case an ’-
              my_ip [my_name]’ is added between the sender and unreach ip  and
              name fields.

       -l     Forks   and   use   the  syslog(3)  facility  to  record  events
              (recommended use).  (root only option).

       -k     Kills the background process started with the -l option.


       The packet decoding is planned for ICMP Unreachable outputs  and  might
       not be significant for all other Icmp types. Output can be shorter when
       implied by the packet size or the icmp type.


       Laurent Demailly <>. Free software.