Dear All,
Exchange details:
Exchange 2010 SP1
2x CAS/HT servers (VMware)
2x MBX servers (VMware)
Both CAS servers are load balanced by NLB using multicast. Cas array address is 10.1.62.41
Cas Server 1 - 10.1.62.3 and NLB Nic is 10.1.62.3 (NO default gateway)
Cas Server 2 - 10.1.62.21 and NLB Nic is 10.1.62.35 (NO default gateway)
The issue i have is that CAS server 2 keeps on reporting the following error:
NLB cluster [10.1.62.41]: NLB detected duplicate cluster subnets. This may be due to network partitioning, which prevents NLB heartbeats of one or more hosts from reaching the other cluster hosts. Although NLB operations have resumed properly, please investigate
the cause of the network partitioning.
This then knocks that host into a pending state.
A restart does not fix the issue. The only way to fix the issue is to change the cluster to unicast and then back to multicast.
I have modififed the up stream switches to accomdate nlb multicast with a static arp entry.
Also i never get this issue with Cas server 1.
This issue is causing outlook to disconnect from the cas servers. Both cas servers are configured the same.
Any help would be very greatful..
Thanks