Linux route命令 总结

Linux查看命令方法：

man
manual
上面两个命令可以查询一个命令的用法

命令后边加上 --help，也可以查看一个命令的用法

route命令 man route

[[email protected]-172-31-42-6 ~]# man route

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

NAME
       route - show / manipulate the IP routing table

SYNOPSIS
       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]

NOTE
       This program is obsolete. For replacement check ip route.

DESCRIPTION
       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) pro‐
       gram.

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

OPTIONS
       -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/net‐
              work names.

       -net   the target is a network.

       -host  the target is a host.

       netmask NM
              when adding a network route, the netmask to be used.

       gw GW  route packets via a gateway.  NOTE: The specified gateway must be reachable first. This usu‐
              ally  means that you have to set up a static route to the gateway beforehand. If you specify
              the address of one of your local interfaces, it will be used to decide about  the  interface
              to which the packets should be routed to. This is a BSDism compatibility hack.

       metric M
              set the metric field in the routing table (used by routing daemons) to M.

       mss M  sets  MTU (Maximum Transmission Unit) of the route to M bytes.  Note that the current imple‐
              mentation of 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 gener‐
              ally only set by routing daemons.

       dev If force the route to be associated with the specified device, as the kernel will otherwise try
              to  determine the device on its own (by checking already existing routes and device specifi‐
              cations, 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.

EXAMPLES
       route add -net 127.0.0.0 netmask 255.0.0.0 dev lo
              adds the normal loopback entry, using netmask 255.0.0.0 and associated with the "lo"  device
              (assuming this device was previously set up correctly with ifconfig(8)).

       route add -net 192.56.76.0 netmask 255.255.255.0 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 0.0.0.0 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 192.57.66.0 netmask 255.255.255.0 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 224.0.0.0 netmask 240.0.0.0 dev eth0
              This is an obscure one documented so people know how to do it. This sets all of the class  D
              (multicast) IP routes to go via "eth0". This is the correct normal configuration line with a
              multicasting kernel.

       route add -net 10.0.0.0 netmask 255.0.0.0 reject
              This installs a rejecting route for the private network "10.x.x.x."

OUTPUT
       The output of the kernel routing table is organized in the following columns

       Destination
              The destination network or destination host.

       Gateway
              The gateway address or '*' if none set.

       Genmask
              The netmask for the destination net; '255.255.255.255' for a host destination and  '0.0.0.0'
              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. lo).

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

FILES
       /proc/net/ipv6_route
       /proc/net/route
       /proc/net/rt_cache

SEE ALSO
       ip(8)

HISTORY
       Route for Linux was originally written by Fred N.   van  Kempen,  <[email protected].nl.mugnet.org>  and
       then  modified  by  Johannes  Stille and Linus Torvalds for pl15. Alan Cox added the mss and window
       options for Linux 1.1.22. irtt support and merged with netstat from Bernd Eckenfels.

AUTHOR
       Currently maintained  by  Phil  Blundell  <Philip.[email protected].com>  and  Bernd  Eckenfels  <net-
       [email protected].inka.de>.

net-tools                                       2013-06-15                                        ROUTE(8)
 Manual page route(8) line 195/214 (END) (press h for help or q to quit)

route命令 route --help

Usage: route [-nNvee] [-FC] [<AF>]           List kernel routing tables
       route [-v] [-FC] {add|del|flush} ...  Modify routing table for AF.

       route {-h|--help} [<AF>]              Detailed usage syntax for specified AF.
       route {-V|--version}                  Display version/author and exit.

        -v, --verbose            be verbose
        -n, --numeric            don't resolve names
        -e, --extend             display other/more information
        -F, --fib                display Forwarding Information Base (default)
        -C, --cache              display routing cache instead of FIB

  <AF>=Use -4, -6, '-A <af>' or '--<af>'; default: inet
  List of possible address families (which support routing):
    inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25) 
    netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP) 
    x25 (CCITT X.25)