linux route命令输出详解

输出详解
route命令输出的路由表字段含义如下：
Destination 目标
The destination network or destination host. 目标网络或目标主机。

Gateway 网关
      The gateway address or '*' if none set. 网关地址，如果没有就显示星号。

Genmask 网络掩码
      The  netmask  for  the  destination net; '255.255.255.255' for a
      host destination and '0.0.0.0' for the default route.


 Flags：总共有多个旗标，代表的意义如下：                        

     o U (route is up)：该路由是启动的；                       

     o H (target is a host)：目标是一部主机 (IP) 而非网域；                       

     o G (use gateway)：需要透过外部的主机 (gateway) 来转递封包；                       

     o R (reinstate route for dynamic routing)：使用动态路由时，恢复路由资讯的旗标；                       

     o D (dynamically installed by daemon or redirect)：已经由服务或转 port 功能设定为动态路由                       

     o M (modified from routing daemon or redirect)：路由已经被修改了；                       

     o !  (reject route)：这个路由将不会被接受(用来抵挡不安全的网域！)

     o A (installed by addrconf)



     o C (cache entry)

Metric 距离、跳数。暂无用。
      The 'distance' to the target (usually counted in  hops).  It  is
      not  used  by  recent kernels, but may be needed by routing dae-
      mons.

Ref   不用管，恒为0。
      Number of references to this route. (Not used in the Linux  ker-nel.)

Use    该路由被使用的次数，可以粗略估计通向指定网络地址的网络流量。
      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 接口，即eth0,eth0等网络接口名
      Interface to which packets for this route will be sent.