IPROUTE(3)                                             IPROUTE(3)

     NAME
          iproute - Internet route table manager

     SYNOPSIS
          bind -a #P /net

          /net/iproute

     DESCRIPTION
          The iproute device allows the specification of routes for
          families of IP addresses.  It maintains a kernel-resident
          routing table for IP addresses used by TCP, IL and UDP.
          Each route consists of a destination IP address, an IP mask,
          and an IP gateway address.  Every packet sent by the system
          is routed according to the route table.  An address matches
          the route table entry when a packet's destination address
          matches the table destination address under the mask. When a
          match is found, the packet is sent to the gateway IP
          address. If there is no match, the packet is sent with the
          original destination address.  If there are several matches,
          the one whose mask has the fewest leading zeroes is chosen.
          (Because of the definition of IP masks, this mask preserves
          the largest portion of the address and is therefore the most
          specific.)  This is forced by storing the routes in decreas-
          ing number of ones order and returning the first match.  The
          default gateway has no ones in the mask and is thus the last
          matched.

          Reading iproute reports the current routes entered in the
          table.  Writing control messages to iproute edits the table.
          Route entries are made by writing a string of format

               add ipdest mask ipgateway

          Entries are deleted by writing a string of format

               delete ipdest mask

          The whole table can be cleared by writing the string
          `flush'.

          For example, to install a gateway address to accept all IP
          packets from a machine:

               g% echo 'add 0.0.0.0 0.0.0.0 192.20.225.225' > /net/iproute
               g% cat /net/iproute
               0.0.0.0 & 0.0.0.0 -> 192.20.225.225

     SEE ALSO
          ip(3), ipconfig(8)

     Page 1                       Plan 9             (printed 12/2/22)