We have an Exchange 2010 environment with 4 cas servers , 2 mb servers and 2 edge servers. All updated to rollup 7. Running on Windows 2008 R2 Sp1 servers.
CA-1 and CA-3 are set up in one NLB cluster and Ca-2 and CA-4 are in another.
CA-2 and CA-4 load balancing works fine.
CA-1 and CA-3 load balancing has a problem. When looking at perfmon, CA-4 is handling over 500 connections and Ca-1 is handling 11.
Both servers have been restarted , all services are running. I have no idea where else to look for the cause of this problem.
When databases are failed over to the site where the problem NLB is located, users experience significant mail delay. When databases are failed over to the site where the working NLB is located, users see no delays.
Where do I start? What do I look at to find the cause of this unbalanced load balancing?