EVPN Border Gateways don't exchange routes in multi-site NDFC

[bmcgahan]

I'm running into a problem with NDFC where the Border Gateways don't exchange EBGP routes in a Multi-Site setup.  It's the same problem described here, but there's no answer. 

The debug message on the Border Gateway Spine is:

2025 Feb 6 17:29:32.099557 bgp: 65002 [30656] (default) UPD: [L2VPN EVPN] 10.112.0.1 10.2.0.2:35067:[2]:[0]:[0]:[48]:[aaaa.bbbb.0444]:[0]:[0.0.0.0]/216 path-id 1 not sent to peer due to: EVPN Border Gateway: no crossing via remote RD

Anyone have an idea what this error means?

The BGP config generated by NDFC is:

router bgp 65002
  router-id 10.2.0.3
  log-neighbor-changes
  address-family ipv4 unicast
    redistribute direct route-map rmap-redist-direct
    maximum-paths 64
    maximum-paths ibgp 64
  address-family ipv6 unicast
    maximum-paths 64
    maximum-paths ibgp 64
  address-family ipv4 mvpn
  address-family l2vpn evpn
  neighbor 10.2.0.1
    remote-as 65002
    update-source loopback0
    address-family ipv4 mvpn
      send-community
      send-community extended
      route-reflector-client
    address-family l2vpn evpn
      send-community
      send-community extended
      route-reflector-client
  neighbor 10.2.0.2
    remote-as 65002
    update-source loopback0
    address-family ipv4 mvpn
      send-community
      send-community extended
      route-reflector-client
    address-family l2vpn evpn
      send-community
      send-community extended
      route-reflector-client
  neighbor 10.10.1.6
    remote-as 65111
    update-source Ethernet1/7
    address-family ipv4 unicast
      next-hop-self
  neighbor 10.112.0.1
    remote-as 65001
    update-source loopback0
    ebgp-multihop 5
    peer-type fabric-external
    address-family l2vpn evpn
      send-community
      send-community extended
      rewrite-evpn-rt-asn
evpn

[bmcgahan]

@Robert Burns have you seen this error before? 

 path-id 1 not sent to peer due to: EVPN Border Gateway: no crossing via remote RD

[bmcgahan]

@Lukas Krattiger  I'm grasping at straws  : ) 

Any idea what this error means?

[bmcgahan · Accepted solution]

In case anyone is reading this in the future... I finally found the issue : )

This log means that the VNIs aren't advertised between sites because those Networks are not attached to the Border Gateway.

Once you "attach" the Network to the Border Gateway, like you do a Leaf, it will start advertising that segment.