We saw a gradual degradation of DHCP services lately. Several machines (XP) wouldn't get an address unless they renewed / released repeatedly.

Overnight, DHCP came to a halt, essentially bringing down the network. We rebooted the NW65 server (only server in the tree) and loaded DHCPSRVR with -D3.

The debug screen showed requests flying in, and as far as I could tell, it was all working. However, non of the workstations, even the ones specified by hostname in the debug, actually recieved an address.

As a stop-gap-save-our-jobs measure, we assigned the Cisco 3500 workstation ports to a different vlan so DHCP servers in another tree would provide addresses.

That's working for now, but I'm not sure where to look for the problem.