monline

The DebuggingLTSP page at the Ubuntu Wiki lists a number of tools that can help isolate various issues like problems with power saving modes (ie. power usage in idle state), monitoring various system performance metrics (cpu, mem, network, discs), etc.

"tcpmon is an open-source utility for monitoring the data flowing on a TCP connection. tcpmon is used by placing it in-between a client and a server. The client is made to connect to tcpmon, and tcpmon forwards the data to server along-with displaying it in its GUI."

Theoretically the above link takes you to the most recent version of tcpmon. However the project started as an Apache tool. At tcpmon.dev.java.net you can get v1.1 and at ws.apache.org v1.0. But the two are not identical featurewise! The new version lacks the ability to switch between horizontal and vertical layout and more importantly it lacks the XML rendering mode. The latter displays XML content structured, ie. the various nodes are indented based on their level in the XML tree. Unfortunately the old version uses some fixed size font which gets pretty much unreadable at higher resolutions.

"PRTG Network Monitor is the powerful network monitoring solution from Paessler AG. It ensures the availability of network components while also measuring traffic and usage. It saves costs by avoiding outages, optimizing connections, saving time and controlling service level agreements (SLAs)."

I was looking for a free solution to monitor the uptime of an internet connection (using a Windows PC) and stumbled on this one. I admit it's a bit more than I was looking for, but there're not that many free utilities for network monitoring so grab it while you can. The freeware edition handles at most 10 "sensors" (ie. you can setup monitoring of 10 network resources). For monitoring the uptime of your network connection you need only one, so it's more than enough.

I've been using Motherboard Monitor on Windows for years to monitor the temperatures of my PC and automatically shut it down in case of an overheating (eg. if the CPU fan dies). The Temperature Monitor and Hardware Monitor are excellent replacements for the same functionality on my Mac.