From time to time a device running its own DHCP server gets accidentally plugged into our SBS 2003 network. When this happens SBS 2003 shuts down its DHCP service - which means that at 7am the next morning our network grinds to halt.
Presumably there is some logic to why a domain controller would stop it's DHCP server service like that, but I would like for it not to shut down.
How can I go about doing that? Is the best way some DHCP option or is it better via service failure recovery?
As far as I know this is "built in" to SBS 2003 by design and can't be turned off. It's configured like this so that SBS will never start up the DHCP service on a network that has an existing DHCP server, so as to avoid ip addressing issues for clients that are configured to use DHCP.
You might check to see if your switches support "DHCP Snooping" which will allow you to specify which DHCP servers are "authorized" while the unauthorized ones are ignored by the switch.