ip还有连线看上图 子网是24位
大概意思就是：下一跳记得是跳下一台连线的那个口
配置
r1配置：
interface GigabitEthernet0/0/0
ip address 192.168.1.1 255.255.255.0
interface GigabitEthernet0/0/1
ip address 192.168.3.1 255.255.255.0
ip route-static 0.0.0.0 0.0.0.0 192.168.1.2
r2配置：
interface GigabitEthernet0/0/0
ip address 192.168.1.2 255.255.255.0
interface GigabitEthernet0/0/1
ip address 192.168.2.1 255.255.255.0
ip route-static 192.168.3.0 255.255.255.0 192.168.1.1
ip route-static 192.168.4.0 255.255.255.0 192.168.2.2
r3配置：
interface GigabitEthernet0/0/0
ip address 192.168.2.2 255.255.255.0
interface GigabitEthernet0/0/1
ip address 192.168.4.1 255.255.255.0
ip route-static 0.0.0.0 0.0.0.0 192.168.2.1
pc1pingpc2互通
