28. 07. 09
It's at the core of any computer system. If you use any computer in the world, it is 99.9% likely to be connected to a network of some kind.
The internet is the largest network. If you want to communicate with anyone or anything then you will certainly be doing it across a network.
The technology has been around for decades and even now, with the latest layer 3 network switches, your network can be exposed to traffic jams. Keeping an eye on the traffic on your network is vital to keeping your PCs or servers working how they should.
A network monitoring tool is a must. There are numerous ways of setting about monitoring your network and I shall lay out some basics here.
A sudden drop in internet performance or commumication with another machine on your network indicates a network traffic issue of some kind. Take a look at your network device activity lights, PC, hub/switch, router, anything where the data activity lights are flashing like crazy when you're not really doing anything indicates high network activity. Try to isolate the source or target machine by eliminating potential machines, one at a time, by unpluging the network cable from each machine in turn. When the lights stop flashing you know you have just found a machine involved.
The next step is to try and identify the cause on the machine you have identified.
Identifying the process that is sending or receiving large quantities of data will get you 75% of the way to the solution.
MS Windows has the Task Manager. Processes taking up most memory and CPU are the give aways.
Linux has the "top" command which runs in a terminal session and provides similar information.
If you do not have access to other machines on your network, you are going to need a network monitoring tool, to try and identify where the problems are coming from. There are many such tools available for download. Nmap for Linux and Zenmap for Windows are free analysis tools which allow you to identify which port numbers are in use by each machine on your network.
Network.
