If you are attempting to add a subscriber node to an existing Cisco Unified Presence Server cluster across the WAN, chances are you will get the following error during network configuration validation:
“Configuration validation with [publisher name] ([ip address]) failed.
Could not send/receive UDP packets to publisher on port 8500.
- Is this node in the application server list on the Cisco Unified Communication Manager?
- Is Network connection to [publisher name] up?
- Is the MTU size correct for this network?
- Does the network allow packet fragments?”
Here’s a screenshot of the message:
If you talk to Cisco TAC, they will tell you that “CUP servers are very particular to network requirements” and quote you CSCug28096 (Sub Installation over WAN Fails – 3 different instances ver 8.6.4,9.1.1) or a similar bug. Fact is, my installation of the subscriber node failed even on a LAN connection between the nodes. Let me just cut down to the solution:
- Install the new node on the same host as the Publisher (host being the key word here).
- Use VMware vSphere Replication or otherwise copy the VM to the remote data center where it should belong.
- Once the VM is moved, change IP address, subnet mask (if applicable) and default gateway to match the network configuration at the remote site. The system will reboot.
- Update the IP address for the node’s A Record in DNS.
- Verify replication state of the cluster on the Publisher server.
The above workaround has worked flawlessly. Hope it works for you if you are having the same issue.