Deployment KB: VxRack ToR Nexus 9332PQ switches with 40Gb to 10Gb cannot be port-channeled

           

   Article Number:     529886                                   Article Version: 4     Article Type:    Break Fix 
   

 


Product:

 

VxRack AS

 

Issue:

 

 

User requested that the VxRack system be connected to their network via a 40Gb port channel broken out into 4 10Gb subinterfaces from the Nexus 9332PQ uplinks to a pair of Catalyst 6800 switches. (See diagram for detail).   
        

      User-added image   
   
   
    When performing the network uplink task, the port channel would not come up.   
   
    Received a "port not compatible [Buffer boost]" error message.                                                           

 

 

Cause:

 

 

There is a Cisco bug for this scenario, CSCux08987, but no resolution at this time. Refer to Cisco bug for complete information: https://quickview.cloudapps.cisco.com/quickview/bug/CSCux08987                                                           

 

 

Resolution:

 

 

The user contacted their Cisco SE. A workaround was found to configure "no buffer-boost" on all of the sub-interfaces in the Nexus 9332PQ switch. This enables the port channel to come up.