Adding Subscriber node to an existing CUPS cluster

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:

CUPS configuration validation error


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:

  1. Install the new node on the same host as the Publisher (host being the key word here).
  2. Use VMware vSphere Replication or otherwise copy the VM to the remote data center where it should belong.
  3. 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.
  4. Update the IP address for the node’s A Record in DNS.
  5. 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.

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