Hi, My NLB setup is as follows: Each server has 1 NIC hosting the server local IP and an NLB with 2 Cluster IPs in Multicast mode. Our network engineers added a static arp entry for each of the 2 cluster IPs with their corresponding NLB mac addresses. The problem is only the 1st cluster IP configured responds to ping, the additional cluster IP does not. If I remove the cluster IPs in NLB and add them in the other way around i.e. the additional IP is now the 1st IP and the 1st IP is now the additional IP, then the (now) first IP responds to ping but the additional IP does not. Our network engineer traced the traffic and both cluster IPs are responding on the 1st cluster IPs mac address instead of on their own mac address. One workaround is to have both arp entries on the switch have the same mac address. My question is should we be doing this or is something not working as it should? Many thanks in advance, Ross