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ROUTE(8)                                 Linux System Administrator's Manual                                 ROUTE(8)

       route - show / manipulate the IP routing table

       route [-CFvnNee] [-A family |-4|-6]

       route  [-v]  [-A  family  |-4|-6]  add  [-net|-host] target [netmask Nm] [gw Gw] [metric N] [mss M] [window W]
              [irtt I] [reject] [mod] [dyn] [reinstate] [[dev] If]

       route  [-v] [-A family |-4|-6] del [-net|-host] target [gw Gw] [netmask Nm] [metric N] [[dev] If]

       route  [-V] [--version] [-h] [--help]

       This program is obsolete. For replacement check ip route.

       Route manipulates the kernel's IP routing tables.  Its primary use is to set  up  static  routes  to  specific
       hosts or networks via an interface after it has been configured with the ifconfig(8) program.

       When  the  add  or del options are used, route modifies the routing tables.  Without these options, route dis‐
       plays the current contents of the routing tables.

       -A family
              use the specified address family (eg `inet'). Use route --help for a full list. You can use  -6  as  an
              alias for --inet6 and -4 as an alias for -A inet

       -F     operate on the kernel's FIB (Forwarding Information Base) routing table.  This is the default.

       -C     operate on the kernel's routing cache.

       -v     select verbose operation.

       -n     show  numerical addresses instead of trying to determine symbolic host names. This is useful if you are
              trying to determine why the route to your nameserver has vanished.

       -e     use netstat(8)-format for displaying the routing table.  -ee will generate a very long  line  with  all
              parameters from the routing table.

       del    delete a route.

       add    add a new route.

       target the destination network or host. You can provide IP addresses in dotted decimal or host/network names.

       -net   the target is a network.

       -host  the target is a host.

              the route command does not allow the option to set the Maximum Segment Size (MSS).

       window W
              set  the  TCP  window  size  for connections over this route to W bytes. This is typically only used on
              AX.25 networks and with drivers unable to handle back to back frames.

       irtt I set the initial round trip time (irtt) for TCP connections over this route to I milliseconds (1-12000).
              This is typically only used on AX.25 networks. If omitted the RFC 1122 default of 300ms is used.

       reject install  a  blocking  route, which will force a route lookup to fail.  This is for example used to mask
              out networks before using the default route.  This is NOT for firewalling.

       mod, dyn, reinstate
              install a dynamic or modified route. These flags are for diagnostic purposes, and  are  generally  only
              set by routing daemons.

       dev If force  the route to be associated with the specified device, as the kernel will otherwise try to deter‐
              mine the device on its own (by checking already existing routes and device  specifications,  and  where
              the route is added to). In most normal networks you won't need this.

              If  dev  If  is  the last option on the command line, the word dev may be omitted, as it's the default.
              Otherwise the order of the route modifiers (metric - netmask - gw - dev) doesn't matter.

       route add -net netmask dev lo
              adds the normal loopback entry, using netmask and associated with the "lo"  device  (assuming
              this device was previously set up correctly with ifconfig(8)).

       route add -net netmask dev eth0
              adds a route to the local network 192.56.76.x via "eth0".  The word "dev" can be omitted here.

       route del default
              deletes  the  current  default route, which is labeled "default" or in the destination field of
              the current routing table.

       route add default gw mango-gw
              adds a default route (which will be used if no other route matches).  All packets using this route will
              be  gatewayed  through "mango-gw". The device which will actually be used for that route depends on how
              we can reach "mango-gw" - the static route to "mango-gw" will have to be set up before.

       route add ipx4 sl0
              Adds the route to the "ipx4" host via the SLIP interface (assuming that "ipx4" is the SLIP host).

       route add -net netmask gw ipx4
              This command adds the net "192.57.66.x" to be gatewayed through the former route to the SLIP interface.

       route add -net netmask dev eth0

              The destination network or destination host.

              The gateway address or '*' if none set.

              The  netmask  for  the  destination net; '' for a host destination and '' for the
              default route.

       Flags  Possible flags include
              U (route is up)
              H (target is a host)
              G (use gateway)
              R (reinstate route for dynamic routing)
              D (dynamically installed by daemon or redirect)
              M (modified from routing daemon or redirect)
              A (installed by addrconf)
              C (cache entry)
              !  (reject route)

       Metric The 'distance' to the target (usually counted in hops). It is not used by recent kernels,  but  may  be
              needed by routing daemons.

       Ref    Number of references to this route. (Not used in the Linux kernel.)

       Use    Count  of  lookups  for  the  route.  Depending on the use of -F and -C this will be either route cache
              misses (-F) or hits (-C).

       Iface  Interface to which packets for this route will be sent.

       MSS    Default maximum segment size for TCP connections over this route.

       Window Default window size for TCP connections over this route.

       irtt   Initial RTT (Round Trip Time). The kernel uses this to guess about the  best  TCP  protocol  parameters
              without waiting on (possibly slow) answers.

       HH (cached only)
              The  number  of  ARP  entries  and cached routes that refer to the hardware header cache for the cached
              route. This will be -1 if a hardware address is not needed for the interface of the cached route  (e.g.

       Arp (cached only)
              Whether or not the hardware address for the cached route is up to date.