EVPN routes are not being received from one site to another site.
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EVPN routes are not being received from one site to another site.

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Article ID: 406545

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Updated On:

Products

VMware NSX

Issue/Introduction

  • EVPN routes received from an EVPN peer is not installed in the BGP or forwarding table
  • BGP Neighbor table shows pfxRcd column as 0.

    Neighbor        doppelganger V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down State/PfxRcd    PfxSnt  

    ##.##.##.##         -      4      65208        36                   30            0             0    0        00:23:22           0                    13     
    ##.##.##.##         -      4      65208        36                   30            0             0    0        00:23:23           0                    13     

  • Topology -- Site-1 VRF-T0 <--BGP--> Site-1 EVPN-T0 <----EVPN----> Site-2 EVPN-T0 <--BGP--> Site-2 VRF-T0
  • Routes being advertised from Site-1 EVPN-T0 have to be received on the Site-2 VRF-T0 via the Site-2 EVPN-T0. But it couldn't.
  • frr.log shows that the route update is being denied due to self mac
    • 2025/06/26 10:16:26.030486 BGP: ##.##.##.##  rcvd UPDATE about ##.##.##.##/32 IPv4 unicast -- DENIED due to: self mac;
      2025/06/26 10:16:26.030492 BGP: ##.##.##.##  rcvd UPDATE about ##.##.##.##/27 IPv4 unicast -- DENIED due to: self mac;
      2025/06/26 10:16:26.030509 BGP: bgp_attr_ext_communities: router mac 02:50:56:##:##:10 is self mac

Environment

VMware NSX

Cause

The uplink interface MAC of site 2 collides with the EVPN RMAC of site 1. When the MAC collides, prefixes received with those RMACs are denied.

Resolution

The respective uplink interface has to be re-created from the NSX UI Tier-0 interface configuration section to get a non-colliding MAC address.

Validation after interface re-creation

Step - 1 - Collect the site RMAC.

  • command to get the RMAC of a site "get evpn vni"
    • Sample output from site-1
      • VNI: 10###4
          Type: L3
          Tenant VRF: VRF-10##6
          Local Vtep Ip: ##.##.##.##
          Vxlan-Intf: vxlan-10###4
          SVI-If: br-10###4
          State: Up
          VNI Filter: none
          Router MAC: 02:50:56:##:##:10
          L2 VNIs:

 Step - 2 - Cross-check with the other site (site-2) BGP MAC hash

      • Make sure on the site-2 edge command vtysh -c "show bgp mac hash" doesn't have the RMAC of site-1, which was noted down in the previous step. 
      • If the new interface has a new MAC, but the show bgp mac hash still holds the RMAC of site-1, put the edge into MM and exit to clear the table.

 

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