SNOOPY(8)                                               SNOOPY(8)

     NAME
          snoopy - spy on Ethernet packets

     SYNOPSIS
          snoopy [ -abeiltup9 ][ -np ]

     DESCRIPTION
          Snoopy displays the header and first 20 data bytes of pack-
          ets received from the local Ethernet.  The packets displayed
          depend on the options chosen.  The following options each
          select packets from a particular protocol.  If more than one
          flag is given, packets from all those protocols are dis-
          played.

          a    ARP

          b    BOOTP

          e    all Ethernet packets

          i    IP

          l    IL

          t    TCP

          u    UDP

          By default all addresses are translated into system names.
          The option n suppresses this.

          Snoopy runs in promiscuous mode by default, displaying all
          packets it can capture from the Ethernet.  The option p
          causes only packets sent to or from the system snoopy is
          running on to be displayed.

          Option 9 causes the data of TCP and IL messages to be inter-
          preted and displayed as 9P messages.

     FILES
          /net/ether
               Ethernet device

     BUGS
          The CPU servers do not take well to running in promiscuous
          mode.  If run on them, snoopy may kill their Ethernets.

     Page 1                       Plan 9            (printed 12/22/24)