Network Load Balancing - Cannot Ping Cluster IP from Different Subnet Hi guys, I have an NLB cluster set up with 4 web servers on Server 2008. The cluster is working fine and is using Unicast mode. Unable to ping cluster Virtual IP addresses from within the Active member of ClusterXL in High Availability mode (there is no reply). Pings from the Standby member to cluster Virtual IP addresses work fine.
If you are unable to connect to a Windows Server Network Load Balancing (NLB) Virtual IP address configured for Multicast Mode it is because of the way your Cisco switch interacts with Microsoft NLB. Cannot connect to Windows Server NLB Virtual IP address. Cannot ping Windows Server NLB Virtual IP address.
So here's the scenario:
Server is a Windows 2016 w/ GUI installed. IIS installs fine, and it can be pinged, and even the default site viewed externally.
Cannot Ping Ip Address
The server is hosted on a Hyper-V box, it has two network adapters, with the NLB adapter having 'Spoof Mac Address' NOT checked (I tried checking it, no change).
As soon as I remote-install the cluster (unicast - with no errors) I can check the GUI for NLB and see that the cluster/hosts were created correctly. However, at this point the adapter for the NLB (in this case, IP ends in 137) is unreachable. I can no longer see the IIS landing page externally, and I can not ping it.
One other thing I tried (to no avail) was to manually set the MAC address in the Hyper-V settings to the MAC used by the NLB (02-BF-C0-A8-1A-75) but this also has had no impact.
Been on Google for 2 days now, and haven't found a solution. Desperately need to get this to play nice.
Day 3: The natives are restless. Little has changed in the village...
So here's some new info I've found:
Turning off the box, changing the MAC Address (in Hyper-V) to something Random, turning it back on, turning it off, then changing the MAC Address BACK to the NLB MAC (eg: 02-BF-C0-A8-64-64) will make it work. However, there's a caveat:
As soon as you make any change to the NLB on that specific box (it MAY even occur when calling Get-Cluster in Powershell, haven't verified that yet) the IP becomes unpingable again until you repeat the above.
Edit: Verified. The following code when run from ANY computer on the network will cause the NIC to go non-responsive again: