I have a sad network left behind by some careless administrators - I am in the process of figuring out exactly what services are running where, not excluding the possibility that some services are running from two places at once, which is tons of fun.
There are two Windows Server 2003 servers, one Windows Server 2008 server with Exchange 2010 on it and a SonicWall TZ210 between the LAN and the WAN. Computers connected via DHCP reveal the gateway IP address that corresponds to the SonicWall unit, however it doesn't have DHCP enabled.
Where and how might I discover what is running DHCP so I could administer it? I am also concerned about internal DNS and Windows domain services as there appears to be confusing information on the network that conflicts with itself.