Hello,
I just configured our first cluster of Microsoft servers using Multicast NLB.
The gateway of the VLAN is a Cisco 5540 and the servers are connected on a Cisco 3750 stack.
In order to let the ASA forward the frames for this multicast group I had to set the static arp resolution to the Multicast MAC address of this cluster.
No static MAC entry on our switches.
All works fine and multicast is working but...
1) Using wireshark on our NLB nodes I found that frames are destinated to the unicast mac address of the machine. IF I ping from the ASA to the Cluster IP, the ICMP is sent just to ALL the NLB nodes.
2) All frames originated from the NBL nodes has the unicast (physical) MAC address.
2) Other hosts in the same VLAN do not receive any broadcast related to this cluster (multicast is working)
3) on our Cisco 3750 stack, the Multicast MAC address is not in the CAM.
Since just NLB nodes are receiving this traffic, my question is:
HOW can the multicast work if the switch doesn't know anything regarding this cluster?!
thanks,
Paolo
