ROUTE(8C)                            BSD                             ROUTE(8C)



NAME
     route - manually manipulate the routing tables

SYNOPSIS
     /etc/route [-f] [-n] [command args]

DESCRIPTION
     route is a program used to manually manipulate the network routing
     tables.  It normally is not needed, as the system routing table
     management daemon, routed(8C), should tend to this task.

     route accepts three commands:  add, to add a route; addp, to add a
     priority route; and delete, to delete a route.

     The addp command adds a priority route.  The TCP/IP server process will
     use priority routes before default routes or routes established by
     routed(8C). A route added with addp will appear first in the gateway
     table (displayed with the BSD command netstat -r(1)). You can only add
     priority routes with addp.  Routes added manually by route cannot be
     deleted by routed(8C).

COMMAND SYNTAX
     All commands have the following syntax:

       /etc/route command [ net | host ] destination gateway [ metric ]

     where destination is the destination host or network, gateway is the
     next-hop gateway to which packets should be addressed, and metric is a
     count indicating the number of hops to the destination.  The metric is
     required for add and addp commands; it must be zero if the destination is
     on a directly-attached network, and nonzero if the route utilizes one or
     more gateways.  If adding a route with metric 0, the gateway given is the
     address of this host on the common network, indicating the interface to
     be used for transmission.

     Routes to a particular host are distinguished from those to a network by
     interpreting the Internet address associated with destination.  The
     optional keywords net and host force the destination to be interpreted as
     a network or a host, respectively.  If the destination has a "local
     address part" of INADDR_ANY, or if the destination is the symbolic name
     of a network, then the route is assumed to be to a network; otherwise, it
     is presumed to be a route to a host.

     If the route is to a destination connected through a gateway, the metric
     should be greater than 0.  All symbolic names specified for a destination
     or gateway are looked up first as a host name using gethostbyname(3N).
     If this lookup fails, getnetbyname(3N) is then used to interpret the name
     as that of a network.

     You can add a default route as follows:

        /etc/route add default gateway_name [non-zero metric]

     TCP/IP software will use the default route when other routes occuring
     earlier in the routing table have failed, or when there are no other
     possible routes.

     route uses a raw socket and the SIOCADDRT and SIOCDELRT ioctl's(2) to do
     its work.  As such, only the super-user may modify the routing tables.

OPTIONS

     -f     "Flush" the routing tables of all gateway entries.  Using this
            option in conjunction with one of the commands described above
            flushes the tables prior to the command's application.

     -n     Suppress printing symbolic host and network names when reporting
            actions.

DIAGNOSTICS
          add [ host | network ] %s: gateway %s flags %x

     The specified route is being added to the tables.  The values printed are
     from the routing table entry supplied in the ioctl(2) call.  If the
     gateway address used was not the primary address of the gateway (the
     first one returned by gethostbyname(3N)), the
      gateway address is printed numerically as well as symbolically.

          delete [ host | network ] %s: gateway %s flags %x

     As above, but when deleting an entry.

          %s %s done

     When the -f flag is specified, each routing table entry deleted is
     indicated with a message of this form.

          Network is unreachable

     An attempt to add a route failed because the gateway listed was not on a
     directly-connected network.  The next-hop gateway must be given.

          not in table

     A delete operation was attempted for an entry that wasn't present in the
     tables.

          routing table overflow

     An add operation was attempted, but the system was low on resources and
     was unable to allocate memory to create the new entry.

SEE ALSO
     intro(4N), routed(8C);
     Configuring and Managing TCP/IP.