Issue: You installed a new additional Edge Pool, however the replication is not up to date and the topology status shows a red cross.
Solution: The issue can be one of the following:
Make sure that the certificate chain on all lync server are correct and that you do not deploy some certificates into the wrong certificate stores via GPO. More infos can be found here.
The replication is always pushed from the active master frontend lync server via 4443 to the edge server. You can find the active master via:
Get-CsManagementStoreReplicationStatus –CentralManagementStoreStatus > C:\00Install\centralstatus.txt
If you edit the x file then you can find the active master server in the line "ActiveMasterFqdn". Please make sure that every lync frontend server in that pool is able to reach every affected edge server via TCP 4443 (internal interface on the edge).