vPC N7K connected with HA 5508, Link aggregation

[anas.awad]

Hi Guys.

Please i really need some help here

I'm planning for implementation for nexus 7k and WLC 5508

the scenario is we have a WLC 5508 will be configured in HA connected to nexus (N7K-C7009-BUN2-P2). as you know HA for WLC required one MGMT interface and Redundancy-MGMT interface for each (primary & secondary). is it possible

Primary WLC

• Aggregate Two interfaces in the Primary for MGMT, each link will go to one of the nexus core switches
  
• Aggregate Two inter face in the Primary for Redundancy-MGMT, each link will go to one of the nexus core switches

Secondary WLC

• Aggregate Two interfaces in the Secondary for MGMT, each link will go to one of the nexus core switches
  
• Aggregate Two inter face in the Secondary for Redundancy-MGMT, each link will go to one of the nexus core switches

please see the attached for the design

[Reza Sharifi]

Hi,

For management you don't need 2 connection from each 5508 to both Nexus.  You just need one. If one 5508 fails the other one will take over packet forwarding and so you can use the second device's management port to logon.

HTH

[Paul Chapman · Accepted solution]

Hi -

I agree with Reza.  I would like to add, based on my experience with WLCs, that you don't want to split your connections across the VPC either.  I regularly experienced dropped traffic in any split connection scenario. Your best bet is to rely on the WLC redundancy in case of a 7K chassis failure.

Additionally, the WLC only performs link aggregation (LAG) at the global level.  You cannot separate individual SFP ports for specific purposes without disabling LAG.  This means that your best practice is to connect 2, 4, or 8 ports as a single etherchannel to the upstream switch.  Please note that the WLC does not support LACP or PAgP; etherchannels on the upstream switch must be "mode on".

The RP interfaces should be connected back-to-back. Unless you have an explicit need for out-of-band management, you can safely ignore the SP interface.

Here's my recommended topology:

Note: On the N7K you can split the connections across line cards within an individual chassis.  I've also successfully connected WLCs to single-homed Nexus 2000s.

PSC

[anas.awad]

Thank you very much guys. actually this idea came out from the BoQ was designed  with 16 qty SFP (glc-sx-mmd) modules.

Anyhow Thanks again Paul, your topology demonstrate a lot.