影响Linux系统网络中网关配置信息的3种方式
1.生效文件cat /etc/sysconfig/network-scripts/ifcfg-eth0
GATEWAY=10.0.0.254 <- 局域网上网网关地址
命令行优先,且临时生效
[root@host01 ~]# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth00.0.0.0 10.0.0.254 0.0.0.0 UG 0 0 0 eth0 [root@host01 ~]# netstat -nrKernel IP routing tableDestination Gateway Genmask Flags MSS Window irtt Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth00.0.0.0 10.0.0.254 0.0.0.0 UG 0 0 0 eth0
route命令添加
[root@host01 ~]# route add default gw 10.0.0.253[root@host01 ~]# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth00.0.0.0 10.0.0.253 0.0.0.0 UG 0 0 0 eth0
route命令删除
[root@host01 ~]# route del default gw 10.0.0.253[root@host01 ~]# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
查看路由表信息 ----局域网----不用到网关(局域网)
避免为了没有DHCP服务器,如果没有dhcp后会吧自己模拟成169.254.0.0
[root@host01 ~]# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth00.0.0.0 10.0.0.254 0.0.0.0 UG 0 0 0 eth0代表到达任意地址的时候,通过网关默认的网关路由(没有这一条出不了外网)0.0.0.0 10.0.0.254 0.0.0.0 UG 0 0 0 eth0
临时删除网关路由条目方法
[root@host01 ~]# route del default 10.0.0.254SIOCDELRT: No such device[root@host01 ~]# route del default gw 10.0.0.254[root@host01 ~]# route -nKernel IP routing tableDestination Gateway Genmask Flags Metric Ref Use Iface10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth010.0.1.0 10.0.0.11 255.255.255.0 UG 0 0 0 eth0169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
小结:
Ping域名的时候需要解析,wan
PingIP不需要解析:
Ping内网 在254内
Ping网关同的外网不行
[root@host01 ~]# ping 10.0.0.254PING 10.0.0.254 (10.0.0.254) 56(84) bytes of data.64 bytes from 10.0.0.254: icmp_seq=1 ttl=128 time=0.480 ms64 bytes from 10.0.0.254: icmp_seq=2 ttl=128 time=0.252 ms
2.生效文件 /etc/sysconfig/network
GATEWAY=10.0.0.254 有地时候没有(工作可能有)