N5K/N2K topology

[e-chuah]

Hi,  According to the attached topology, it is documented that Topology A is not a supported topology.   We tested topology B. Because of the way vmware perform load sharing (by IP hash), we saw the mac address flapping between Po1 and Po2. We see this by using the command "sh mac address" on the N5K.) There is no error message in N5K. Is topology B a supported topology by Cisco ? Will there be problem with this setup?  Thanks

[Jayakrishna Mada]

Hi,

Yes you are correct Cisco does not support Topology A as of now but will be in future. As far as Topology B is considered it is expected to see MAC flaps on those port-channel unless one is blocking.

With that said the recommended way to connect is to have VPC either between 2k and 5k (active/active mode) and connect the downstream server to 1 2k or  VPC between 2k and server side ( Pass-Throuhg Mode).

Please look at the following document:

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/C07-572831-00_Dsgn_Nexus_vPC_DG.pdf

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/C07-572829-01_Design_N5K_N2K_vPC_DG.pdf

I hope this helps.

JayaKrishna.