I have 2 2008 R2 physical servers on the same subnet and they have been using NLB for the past 1.5 years. We had a firewall issue and I took one of the servers out of the cluster to do testing, while the other main server (priority 1) was left serving
up the virtual IPs. The main server continues to work properly.
The servers have 2 NICs, one for NLB and one just for regular traffic. The NICs also have their own IP addresses and then there is a cluster IP and 2 virtual IPs.
Error:
When I try and add the second server to the cluster, I first connect to existing cluster which works fine. Then I do a Add Host to Cluster, and type the name of the server and select the NLB NIC. It sees the other server and it seems to start the process, however soon after the NLB NIC goes to having internet access to a "enabled" state and the gateway gets taken out of the settings. I try to add it back, but as soon as I get out of the settings it disappears again. NLB manager tells me: cluster ip address (192.#.#.#) not added to tcpip properties. It lists this error 4 times, once for each IP (2 virtual, 1 cluster, and then once for the dedicated NLB NIC IP). I have also tried adding all virtual IPs to the NLB NIC's settings and still same exact error. Registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces -even reg looks good.
Any help would be appreciated. If I can't get any resolution my next step is going to be to delete the NLB cluster on the main server and recreate it....but this requires downtime and got to make sure it comes back up!