GNS3 模拟icmp路由跟踪

R1 :

conf t

int f0/0

no shutdown

ip add 192.168.1.1 255.255.255.0

no ip routing

end

 

R2 f0/0:

conf t

int f0/0

no shutdown

ip add 192.168.1.254 255.255.255.0

end

 

R2 f1/0:

conf t

int f0/0

no shutdown

ip add 192.168.2.254 255.255.255.0

end

 

 

R3 :

conf t

int f0/0

no shutdown

ip add 192.168.2.1 255.255.255.0

no ip routing

end

 

在R1里面添加 ip route 0.0.0.0 0.0.0.0 192.168.1.254映射从R1的路由表,然后ping 192.168.2.1 。思科linux 下是5个包出去，5个包返回。windows下是4个

分析协议可以看到TTL(Time to live)值减1.