====== Cannot Find Zoo Server After IP Address Change ======
> **Product:** //[[zoo4:home|Zoo 4.0]]//
> **Summary:** //Solving an IP address change issue.//

===== Question =====
We needed to change IP addresses and subnet masks of systems on our network. After doing this, our Rhino workstations could no longer get licenses from our Zoo server.

I have checked the Zoo log files, and it appears that the Rhino client requests are heard by the Zoo. But the Zoo's replies are not received by Rhino.

I am not sure why this affects the software. Any clues?

===== Answer =====
If all you’ve done is change IP address and subnet masks, then most likely the problem has to do with NetBIOS name resolution. Rhino and the Zoo communicate via NetBIOS Mailslots. Thus, NetBIOS name resolution must work from both the Rhino workstation and the Zoo. Being able to //ping// each other is not important as Ping does not use NetBIOS. The **Nbtstat** utility is a good tool for testing NetBIOS name resolution.

**Note:** The customer later reported that there were some old entries on his WINS server that were not //tombstoned// or //scavenged//.  After removing these entries, he was able to run **nbtstat –R** from both Rhino workstations and the Zoo server. And, Rhino was, again, able to get licenses from the Zoo.

\\

{{tag>Zoo4}}