Computer Networking: Internet Protocols in Action

Chapter 4.2. Ping and Traceroute

INTRODUCTION

In this exercise, we will introduce two powerful tools for exploring the Internet—ping and traceroute. Ping sends special probe messages to a specific host in the Internet and waits for a reply indicating that the host is "alive" and functioning. The name ping was inspired by sonar equipment that uses echo-location to identify ships. Traceroute maps out all the intermediate hosts along a path to a specific Internet host.

In the following example, we used ping to probe the connection from 128.153.128.2 to www.iana.org (192.0.34.162). Notice that ping reports information about the round trip time.

> ping www.iana.org

PING www.iana.org: 56 data bytes
64 bytes from www.iana.org (192.0.34.162): icmp_seq=0. time=96. ms
64 bytes from www.iana.org (192.0.34.162): icmp_seq=1. time=97. ms
64 bytes from www.iana.org (192.0.34.162): icmp_seq=2. time=123. ms
64 bytes from www.iana.org (192.0.34.162): icmp_seq=3. time=97. ms
----www.iana.org PING Statistics----
4 packets transmitted, 4 packets received, 0% packet loss
round-trip (ms) min/avg/max = 96/103/123

In the following example, we used traceroute to identify the intermediate nodes along the path and the round trip time to each. Traceroute is available on most platforms. The version available under Windows is called tracert instead of traceroute.

Notice that the majority of the delay occurs between hop 10 and 11. From the machine names, it seems likely that intermediate node 10 is located on the East ...