CAS + Offline Address Book

Have: Two CAS server (CAS1 and CAS2) + NLB.

Users can't update OAB (get error 0x8004010F)
Users allways connect to CAS2 server, but default OAB create on CAS1 server.

Q: How i can move or create second OAB on server CAS2. Or i must forward users to server CAS1?

Thanks.