PCInk - 1:17 pm on Oct 31, 2012 (gmt 0)
Thanks for all your help, I think I may have figured it out using your ping/tracert/traceroute suggestions and by asking me to log into the router settings (which I hadn't done).
Firstly, I used the wired connection but it kept dropping so it switched to wireless but had the same issue. Assuming it can't be the network card or router, I tried my phone to connect to the linux box but it wouldn't get any pages. It worked to the windows machine, so the router was still working.
Then, I changed to fixed ip addresses but kept using the wireless and it kept stopping.
Using ping commands and logging into the router answered the questions as to why.
The wireless usb stick must have a 'power-save' mode built into it, possibly intended for use with laptops. It actually switches off after some inactivity and switches back on when the computer it is connected to needs to request something from the network, staying 'alive' for a while afterwards. In its 'asleep' mode, it doesn't respond to incoming 'pings' but outgoing 'pings' work fine - since that 'awakens' it! I found this by logging into the router and looking at the ip addresses of the computers connected to it - the linux box was dropping off the list after a while.
So my first problem may have been DHCP since the wired didn't work. The problem with fixed ip addresses was the wireless product I was using. This would explain why it only worked with wired connection AND the fixed ip address combination.
Now I know the issue, it has never shown the problem with that USB stick because it has only been used on a couple of machines that always have Outlook running, picking up emails - thus keeping it from going 'asleep'.
Hopefully, this may help others who have a similar problem.