I'm currently having an issue where NLB failover is working inside the firewall but not outside. I currently have the FQDN EXCHNLB.domain.org pointing to the IP 10.x.x.x internally. If I attempt to connect to that hostname with https://EXCHNLB.domain.org/owa from an internal machine, I can get the OWA page without any issues for the two CAS servers I have that are part of the NLB cluster. I can stop either host in the cluster manager and when I reconnect it will seamlessly fail over to the other one. However, when I connect to https://external_public_IP/owa
externally, which NATs to 10.x.x.x, failover does not work. The requests always go to one CAS server only and if I stop that server in the cluster manager OWA access no longer works. Why would failover work inside the firewall but not outside?
I'm using multicast NLB and both CAS boxes are virtusl machines on ESXI.