I think he's talking about a network monitor not a protocol analyser. Ethereal and Microsofts NetMon are analysers.
Do you just need a tool that occasionally pings the server and shows you whether its up or down ? There are many little utils that do that. On the other hand if you want something that lets you use SNMP and change configuration.. i don't think you'll get a free one... unless you use linux.
Well I happened to just look for a few network management/monitoring tools with all the buzz and whistles on it, and I think I have found one that might be worth trying, but its not free However you can still grab an evaluation license.
The name is AdventNet ManageEngineTM OpManager and the screen shots look quite sexy