Hi Glenn,

Thanks for your response. Always helpful.

We have a brand new switch which I have used in several other schools so I know its not the switch.

I will query regarding the cabling as the school are having building works going on - so you may have something there. However, hopefully the BT router was the problem. The new Router does seem to be faster.

I was actually going to buy Cables to Go Patch leads for the cabinet and for the computers to replace all the existing cabling - Cables 2 Go What do you think of these cables. I had a look at the specs and they seem to higher than the average standard - ie 350Mhz, 24AWG, Gold Plating - 50µm

I will ask my cabling guy if he has anything that can test for noise on the network as a result of poor terminations. That school does have cabling that was put in some years ago that was done by a professional company - sort of a handyman's job. Not that the issue has anything to do with this I think because the only thing that was not working was the Internet. Access to the servers worked, printers worked etc and the cabling was installed years ago. It is interesting to know that poor cabling can cause that kind of problem.

With regards to the DNS - I am not sure what you are recommending here. When I started my broadband service a couple of years ago, I set it up to use the Windows DNS Servers Root Hints Servers for Internet Resolution. This worked fine for a couple of months when all of a sudden the Internet stopped working at several clients - on the same day. I changed it so that the windows server forwards to the BT router which then uses the BT Internet Routers and I have never had a problem since. So I am reluctant to change it back to using the root hints given that the Internet stopped working at several clients on the same day!

At the moment the setup that I have is the clients use the windows server as the default server. Anything that the windows Dns server cannot resolve (ie non domain computers) gets forwarded to the BT router which then connects to the ISP Dns Servers. Are you saying that you would use the internal DNS server for both internal Domain Name resolution and for Internet resolution?

I will have a look at this OpenNMS that you refer to. Maybe I can get it to work with the new switch we bought - a Cisco SLM2048PT-UK

I think my first port of call would be to install some network monitoring software to see if there is any traffic that is unusual. I am busy researching that now.

Thanks for the input. Helpful to know that I have not missed too much.