Linux Shell Scripting Cookbook - Third Edition

Tracing a route

The traceroute command discussed in Chapter 8, The Old-Boy Network traces a packet's entire path from the current host to its destination. The route get command reports the next hop from the current machine:

$ ip route get 172.16.183.138
172.16.183.138 dev vmnet8 src 172.16.183.1
cache mtu 1500 hoplimit 64

The preceding return shows that the route to the virtual machine is through the vmnet8 interface located at 172.16.183.1. The packets sent to this site will be split if they are larger than 1,500 bytes and discarded after 64 hops:

$ in route get 148.59.87.90
148.59.87.90 via 192.168.1.1 dev eth0 src 192.168.1.3
cache mtu 1500 hoplimit 64

To reach an address on the Internet, a packet needs to leave the local network via ...