Thanks,
They dont NEED to do it - they have a tendency of doing it when something goes wrong with their network - we do tell them not to...
Not using Cisco kit. Standard Intel nework card on the Windows XP Pro PC connecting directly to an unmanaged Siemens switch and then that connects to the DSLAM.
Addresses in our network are all 200.200.100.x starting at x=1 to x= 110. Subnet of 255.255.255.0 on all PCs.
Didnt realise it would be this compicated as Im sure in the past I just set up a 2nd address for Win xp network card and it worked - but doent seem to now...