NT4 BDC Login

I have an old domain here (NT4). Correct me if I am wrong but if my PDC goes down my BDC should be able to authenticate any user logging in right!!?? I have shut down the PDC as a test and tried logging in and was not able to access different servers in the domain. The BDC is located in a different location (segment) does the DHCP Manager have to be setup exactly like the PDC is that the problem?? WINS and DNS is configured the same.

Help please!