Many network administrators today hail from the old-school days of CLI, the venerable Command Line Interface. It seems everything these days is done in a windowed browser, but if you can remember when DOS was the operating system, instead of just a shell, then you probably remember it wasn't all bad. In fact, the CLI had some pretty useful features.
It seems to me that as a network administrator, what I like about graphical interfaces is the way they present data to me, i.e. output. But what I like about command line interfaces is the way I can tell the device what to do, i.e. input. I believe the reason for this, is that the tasks of a network administrator are often very repetitive. We do the same things over and over, each time, changing an IP address here, or a parameter there, as we go about configuring lots of similar systems, as well as lots of diverse systems. And these tasks are easy to repeat from a CLI, but often cumbersome from a GUI.
In the routing and switching world, 99% of the work still gets done on a command line (typically via telnet) even though most router and switches have WWW and SMTP and other types of interfaces. This is often true in the Linux and UNIX worlds as well, and the reason in both cases is the power and flexibility of scripting.
Not surprisingly the standout in this world is Microsoft's Windows, where tasks are no less repetitive, but nevertheless, are almost always performed with a mouse. I think this is because most Windows administrators don't know about the "netsh" interface.
If you find yourself responsible for configuring the network settings for a large number Windows 2000 servers (or later), look up the "netsh" command in help. This command is a fairly powerful scripting tool where you can configure everything from RAS to OSPF to IGRP to DNS and PROXY settings, as well as the simple things like IP addresses and subnet masks. You can even use "netsh" to configure computers remotely, and you can work offline or online.
Tom Lancaster, CCIE# 8829 CNX# 1105, is a consultant with 15 years experience in the networking industry, and co-author of several books on networking, most recently, CCSPTM: Secure PIX and Secure VPN Study Guide published by Sybex.