Microsoft NLB over vPC not working on the Nexus 5672-16G

[Menelaos Sazos]

Hi!

Now facing an issue when a vPC-attached ESXi (not e-vPC, not vPC+) with MS NLB cluster members is not reachable by the clients connected from other vPC-attached ESXi. Interestingly, a vPC-attached client can reache the MS NLB cluster, located on the orphaned port. In both cases NLB and client are in the same VLAN.

MS NLB type is "IGMP Mode", Nexus 5672-16G has static CAM entries configured for the MS NLB MAC-address and an SVI with the static ARP for the NLB.

Searching other requests, I didn't find any case exactly like this.

[Menelaos Sazos]

Update: found that inside a single ESXi NLB IP is unreachable too. Investigating that first.

[Menelaos Sazos]

Finally, got it to work. The ESXi was required to configure "Multicast filtering mode: Basic".

Static MAC entries are not required on the Nexus 5672-16G with NX-OS 7.3.