Network Topology Discovery and Configuration Discovery

Experiment 1. Network Topology Discovery

In this experiment, you are asked to use a simple network utility program traceroute to discover network topology between your machine and some web servers. For example, to probe the network connection to www.mit.edu, just type traceroute www. mit.edu (unix or linux) or tracert www.mit.edu (MS windows) at command interface; and you will get a list of gateway routers on the way and delays to reach each of them. Consult unix man pages for more sophisticated usage of traceroute.

The web servers you contact should include two types: well known ones (e.g., www.mit.edu , www.yahoo.com , etc.) and lesser known but neighboring ones (e.g., www.las-cruces.org (city of las cruces), www.lcsun-news.com (las cruces sun news)). You should probe at least two for each type.

A related utility is ping, experiment with it.

You can use any computer to perform the experiment. Be ware that traceroute may be disabled in some departmental unix/linux machines since it reveals much information about network topology and hence poses a security risk, in that case try tracert on windows or on your home computer. Also, for the same reason, some routers do not respond to traceroute/tracert. In such case, change to another website.

The deliverables of the lab are:

1. A report (must be typed, half page or less in length) discussing your observations of the traceroute output. Hint questions helpful to stimulate your discussion (others are also possible): How do the network connections of the two types of web servers differ? Anything surprises you? Can you guess which ISPs your packets have visited?

2. A copy of your traceroute output.