ip route 命令介绍

ip route 可以用于查看网络的路由信息，并设置路由表

• route n 显示所有路由

  [root@ceph-104 ~]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         10.229.37.1     0.0.0.0         UG    101    0        0 enp2s1
  10.229.37.0     0.0.0.0         255.255.255.0   U     101    0        0 enp2s1
  111.192.168.0   0.0.0.0         255.255.255.0   U     100    0        0 enp2s3
  192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
  
  显示结果在前的路由优先使用
  

• ip route show 查看路由信息

  [root@ceph-104 ~]# ip route show
  default via 10.229.37.1 dev enp2s1 proto static metric 101
  10.229.37.0/24 dev enp2s1 proto kernel scope link src 10.229.37.231 metric 101
  111.192.168.0/24 dev enp2s3 proto kernel scope link src 111.192.168.104 metric 100
  192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown
  

• ip route get ip 查看到达该ip地址的路由信息

  [root@ceph-104 ~]# ip route get 111.192.168.101
  111.192.168.101 dev enp2s3 src 111.192.168.104 uid 0
      cache
  [root@ceph-104 ~]#
  

• ip route add/delete

  # 添加到主机的路由
  [root@ceph-104 ~]# route add -host 目的IP dev 选择经过的网卡
  [root@ceph-104 ~]# route add -host 111.192.168.101 dev enp2s3
  [root@ceph-104 ~]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         10.229.37.1     0.0.0.0         UG    101    0        0 enp2s1
  10.229.37.0     0.0.0.0         255.255.255.0   U     101    0        0 enp2s1
  111.192.168.0   0.0.0.0         255.255.255.0   U     100    0        0 enp2s3
  111.192.168.101 0.0.0.0         255.255.255.255 UH    0      0        0 enp2s3  # 添加到主机的路由（经过指定网卡）
  192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
  
  [root@ceph-104 ~]# route add -host 目的IP gw 经过的网关
  [root@ceph-104 ~]# route add -host 111.192.168.101 gw 111.192.168.1
  [root@ceph-104 ~]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         10.229.37.1     0.0.0.0         UG    101    0        0 enp2s1
  10.229.37.0     0.0.0.0         255.255.255.0   U     101    0        0 enp2s1
  111.192.168.0   0.0.0.0         255.255.255.0   U     100    0        0 enp2s3
  111.192.168.101 111.192.168.1   255.255.255.255 UGH   0      0        0 enp2s3 # 添加到主机的路由（经过网关）
  192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
  #删除路由
  [root@ceph-104 ~]# route del -host 111.192.168.101   删除一条匹配的路由
  route del -host 111.192.168.101 gw 111.192.168.1     删除匹配的路由
  [root@ceph-104 ~]# route del -host 111.192.168.101 dev enp2s3 删除匹配的路由
  # 添加到主机的路由
  
  
  #添加到某网段的路由
  # 增加一条路由信息（发送到10.229.37.0网段的通信包全都要经过10.229.37.1这个网关）
  [root@ceph-104 ~]# route add -net 10.229.37.0 netmask 255.255.255.0 gw 10.229.37.1
  [root@ceph-104 ~]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         10.229.37.1     0.0.0.0         UG    101    0        0 enp2s1
  10.229.37.0     10.229.37.1     255.255.255.0   UG    0      0        0 enp2s1	# 新增的路由信息
  10.229.37.0     0.0.0.0         255.255.255.0   U     101    0        0 enp2s1
  111.192.168.0   0.0.0.0         255.255.255.0   U     100    0        0 enp2s3
  192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
  
  # 删除一条路由信息
  [root@ceph-104 ~]# route del -net 10.229.37.0 netmask 255.255.255.0
  [root@ceph-104 ~]# route -n
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
  0.0.0.0         10.229.37.1     0.0.0.0         UG    101    0        0 enp2s1
  10.229.37.0     0.0.0.0         255.255.255.0   U     101    0        0 enp2s1
  111.192.168.0   0.0.0.0         255.255.255.0   U     100    0        0 enp2s3
  192.168.122.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr0
  
  #添加到某网段的路由
  

• 设置永久路由的方法

  （1） 在/etc/rc.local里添加

  # 配置的路由信息
  route add -net 192.168.3.0/24 dev eth0
  route add -net 192.168.2.0/24 gw 192.168.3.254
  

  （2）在/etc/sysconfig/network里添加到末尾

  GATEWAY=gw-ip` 或者 `GATEWAY=gw-dev
  

  （3）/etc/sysconfig/static-router :

  # 设置静态路由
  any net x.x.x.x/24 gw y.y.y.y