Linux系统路由配置说明

• 添加到主机的路由

# route add -host 192.168.1.2 dev eth0:0
# route add -host 10.20.30.148 gw 10.20.30.40

• 添加到网络的路由

# route add -net 10.20.30.40 netmask 255.255.255.248 eth0
# route add -net 10.20.30.48 netmask 255.255.255.248 gw 10.20.30.41
# route add -net 192.168.1.0/24 eth1

• 添加默认路由

# route add default gw 192.168.1.1  //默认只在内存中生效

• 删除路由

# route del -host 192.168.1.2 dev eth0:0
# route del -host 10.20.30.148 gw 10.20.30.40
# route del -net 10.20.30.40 netmask 255.255.255.248 eth0
# route del -net 10.20.30.48 netmask 255.255.255.248 gw 10.20.30.41
# route del -net 192.168.1.0/24 eth1
# route del default gw 192.168.1.1  //删除所有的默认路由：route del default

• 设置包转发

# vim /etc/sysctl.conf
net.ipv4.ip_forward = 1
# sysctl -p

• 路由永久生效

# vim /etc/network/interfaces

auto eth0
iface eth0 inet static
  address 192.168.2.1
  network 192.168.2.0
  netmask 255.255.255.0
  broadcast 192.168.2.255
  gateway 192.168.2.254
  up route add -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.2.2 dev eth0
  down route del -net 192.168.3.0 netmask 255.255.255.0 gw 192.168.2.2 dev eth0
  up route add -net 192.168.4.0 netmask 255.255.255.0 gw 192.168.2.2 dev eth0
  down route del -net 192.168.4.0 netmask 255.255.255.0 gw 192.168.2.2 dev eth0