NLB with 3com 8810's and 5500's

[achensen]

I'm planning on implementing NLB with two servers which are connected (no teaming) to two different 5500-stacks which on their turn are connected to two 8800's. One of the 8800's is the VRRP active router for the VLAN the servers are connected to. It also has the active connections from the 5500's as the 5500's block the interface to the other 8800 by MSTP.

In other threads I've read that I should use NLB with multicast, no unicast. But I still have some questions.

- The 8800's are the routers (VRRP) for the VLAN so I should add static ARP for the virtual mac-address of NLB only on the two 8800's right?
- On both 8800's I should add a static multi-port mac-address for the virtual mac-address of NLB. I assume I should on the 'passive' 8800 add the static multi-port mac-address pointing to the interfaces which would be unblocked in case the 'active' 8800 should fail and STP en VRRP failover. Is this true?
- Now, also considering the default differences in 5500's and 8800's, which settings should be true? Is usage of IGMP preferable or just plain multicast? Multi-cast routing should only be enabled on the VLAN-interfaces (on the 8800's)?

 

[achensen]

Guess I can nog answer the question myself, since I've just figured it out (checked, it works like a charm).

So it's two 5500's and two 8800's. NLB-interfaces of the servers are connected to g1/0/1 on the different 5500's. Interfaces t1/1/1 on both switches are connected to g1/1/1 and g1/1/2 on 8800-1 and t2/1/1 on both 5500's are connected to g1/1/1 and g1/1/2 on 8800-2.

On the 8800's I've set:
arp static 1.2.3.4 03bf-0a01-0352 99 multi-port g1/1/1
arp static 1.2.3.4 03bf-0a01-0352 99 multi-port g1/1/2

99 is the VLAN id and 1.2.3.4 is the cluster address for NLB.

On the 5500's I've set:
mac-add multicast 03bf-0a01-0352 int g1/0/1 int t1/1/1 int t2/1/1 vlan 99

If you don't add the t1/1/1 the cluster doesn't seem to communicate properly. If you don't add t2/1/1 than the servers are unable to communicate when a failover of the 8800's occurs.

Kind regards