Nexus load-balance over vpc

[Elleku1985]

Hello,

I have a pair of Nexus 7000 (NX-OS 6.2) in vpc domain, each of them equipped (in a vDC different from the admin one) with a Nexus 2248TP FEX.

On the two fex I created a 4xGbE vPC (2 ports on each FEX) connected to an EMC DataDomain device, that replicates storage data to another DataDomain located in a different site.

As both the source and destination IP and MAC address are always the same in the replication traffic, I changed the load balancing method on both Nexus 7000 Admin vDC to XOR source and destination L4 ports.

The result is that the traffic is balanced always on the same two ports of the same FEX, and is not sent over the vPC peer-link to the other two ports on the second FEX, even if there are more than 8 sessions with different l4 source ports.

Does anyone ever had the same problem, or have any suggestion?

Thank you,

Lucio

[Reza Sharifi]

Hi,

The traffic is not supposed to go over the VPC peer link.  If you want to have load balancing over 4 link, you need to connect all 4 links from the same FEX to one 7k, as dual FEX uplink to 2 different 7ks is not supported.

HTH

[Elleku1985]

Hi,

thank you for your answer.

Actually FEXs are not dual homed to N7K, but each fex is connected to a single N7K.

The DataDomain is then dual homed to the two FEXs (2 link on each FEX) in vPC.

I saw on the online documentation that this topology should be supported.

I attach to the discussion a simple picture showing the connections.

Thank you,

Lucio