here is a real fun one i met the other day – an although I have a fix – i thought I post it anyway for comments / confirmations that my theories are right.
.under what circumstances an IP gateway can become ‘promiscuous’ ? Is it a normal condition for gateways to advertise themselves (and thus have the ability to override your Windows IP settings (in this case licensed with DHCP)
The we have been upgrading the LAN backbone here and as such, have added and Intel fibre patch/hub – which seems to advertise itself as a gateway (which it isn’t) – or at least respond quicker than the existing default gateway. This causes your PC to learn that this is the new route – and installs it as the 1st choice in the route list (some else I didn’t know your PC does….type ROUTE PRINT at the dos prompt and woweee.)
The fix is either manually edit this pc-based routing table, or renew your dhcp licence, or reboot your pc.
Maybe it’s the norm but I a) never knew gateways behaved or couldbehave like this and