Q & A on Netweork Analyzer Software,

Q: I am planning to use your book, Computer Networks and Internets, for my class (Computer Networks) in the coming Fall semester. As you wrote in the preface that students seem to understand more on the material if they see packets on a real network. You also mention about an inexpensive network analyzer software. Would you please give me the name of the network analyzer software that good but not too expensive? The department cannot afford to by an expensive HP network anlyzer.

A: Here at Purdue, we have used a variety of network analyzer software running on a workstation (i.e., a PC) rather than a dedicated box. Currently, we're using 'snoop' (a program available with Solaris); we used to use 'etherfind'. To make it 'safe' for undergrads, we (1) install an extra NIC in each workstation that connects to an experimental network, and (2) use the sudo program to invoke snoop, which restricts what the students are allowed to do.

I should tell you that, it's not difficult to roll your own -- as a first project in my graduate-level internetworking course, I have each student build an analyzer (put the interface card in promiscuous mode and selectively dump packets).

Q: I totally agree with you that teaching computer network, the lab is a must. Your book is very good, you make something so complex to be simple.

A: Thanks.

Q: I will teach this course for one-semester, what Parts should I cover? Part 1 through 3 as you suggested in the preface?

A: I'm currently teaching a senior-level networking course from the text, with the following empahsis:

• 1.5 weeks : Introduction, signals, media, bandwidth, throughput, snd multiplexing

• 5.0 weeks: Packet transmission concepts and technologies; LANs, WANs, and local loop technologies

• 5.0 weeks: Internetworking fundamentals and internals
• 3.0 weeks: Internet applications