2 Replies Latest reply: Mar 7, 2019 3:13 PM by Luke RSS

    VXLAN + vPC: Backup Routing SVI


      I have a question around using the backup routing SVI. Especially when using Ingress Replication.


      As you know, Ingress Replication is the small-scale alternative to using multicast.

      I've read in a few places now that there is no multicast configuration required when using IR, and in my experience this seems to be correct.


      However, in a Cisco Live presentation (BRKDCN-3040) it sounds like PIM Sparse Mode command is required on the backup routing SVI, even if IR is used.


      Has anyone here done this in production? Do you find you need this command?

        • 1. Re: VXLAN + vPC: Backup Routing SVI

          I would say that based on this: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/vxlan/configuration/guide/b_Cisco_Nexus_9000_…


          Considerations for the Transport Network

          The following are considerations for the configuration of the transport network: 

          •   On the VTEP device: 
            • Enable and configure IP multicast.* 

            •   Create and configure a loopback interface with a /32 IP address. 

              (For vPC VTEPs, you must configure primary and secondary /32 IP addresses.) 

            •   Enable IP multicast on the loopback interface.*  <<<<<
            •   Advertise the loopback interface /32 addresses through the routing protocol (static route) that runs in the transport network. 
            •   Enable IP multicast on the uplink outgoing physical interface.* 
          •   Throughout the transport network: 
            • Enable and configure IP multicast.* 

          •   The use of the system nve infra-vlans command is required for the VLANs carried on the peer-link that are not locally mapped to an L2VNI segment. 
            • The system nve infra-vlans command specifies VLANs used by all SVI interfaces on vPC peer-links in VXLAN as infra-VLANs.

            •   You should not configure certain combinations of infra-VLANs. For example, 2 and 514, 10 and 522, which are 512 apart. 


          * Not required for static ingress replication or BGP EVPN ingress replication.  <<<<<<



          You should not be required to have this configured.

          • 2. Re: VXLAN + vPC: Backup Routing SVI

            Thanks Jaime,


            This backs up my testing too. It doesn't seem to need it.