Open Directory Master Kerberos Realm, Not like IP Address

Hello, I am setting up a MacPro to take the place of our Dual G5. The G5 is running off of DSL which had 2 different IP address's, 1 ending in .pacbell.net and the other being the standard xx.xx.xxx.xx numeric values. My problem is that the MacPro is running off of a freshly implanted T1, but the only IP I have is in the xx.xx.xxx.xx , the problem I see is the OD is setting the realm to local when I input this IP address....not allowing my LDAP users to really be recognized, I want to move over all of my portable home directories to the new server, which I could easily do by putting the old server in Firewire Disk mode, I tried the home folder copy within Workgroup manager, but it is as if my LDAP cannot be seen....anyone?? Please help. Thanks.