Today I've tried to implement NLB on a working DA 2012R2 server (IP-HTTPS only). The internal interface is configured for IPv4 & IPv6 and the external interface is configured for IPv4 only. The installation went well and I have choosen the Multicast cluster mode.
I can happily IPv4 & IPv6 ping the internal DIP & VIP from any internal server. I've verified that for the DIP the adapters Physical Address is used (00-50-56-87-4B-EF) and for the VIP the ClusterNetworkAddress (03-bf-2a-03-a9-30). The latter one is a multicast MAC because the low order bit in the high order octet in the MAC address is1.
However from a device on the *same* subnet as the external interface (i.e. the core switch) I can IPv4 ping the external DIP but *not* the VIP. For the DIP the adapters Physical Address is used (00-50-56-87-6A-E8). Taking a Wireshark trace on the DA server reveals that the ARP request for the external VIP is *not* answered by the DA server.
Note that no errors are reported by the NLB or RA management consoles. Any help is welcome to get that beast working.
Best regards,
Stefaan