HUB transport role in DAG
Posted on 2011-09-05
I have two Exchange servers. One of them has CAS, HUB, MB roles. Another one has HUB, MB roles. These servers are in DAG.
Before current config there there was only one HUB server and messages were sending normally.
After I installed HUB server on second server messages can be send only through old HUB server and when they are sending through new one they hangs in queue with error:
Delivery Type DnsConnectorDelivery
451 4.4.0 Primary target IP address responded with: "421 4.2.1 Unable to connect." Attempted failover to alternate host, but that did not suceed. Either there are no alternate hosts, or delivery failed to all alternate hosts.
Incoming messages passes normally.
Send connectors are similar for both HUB servers.
What can cause such a problem?