Arista EVPN VXLAN Configuration Example (1c) - eBGP Overlay

After the eBGP Undelay is up, we can move on to the eBGP Overlay.

Topology and configuration:


Explanations:

• The BGP AS# of spine and leaf routes are different, so need to use BGP local-as feature to form iBGP peering
• The benefit of BGP RR is that, the NH of EVPN updates are unchanged
• Also need to disable the RR under address family ipv4 unicast or configure "no bgp default ipv4-unicast" under router bgp, otherwise you will see the following failed neighbor

bn303-eSpine1#show ip bgp summary

BGP summary information for VRF default

Router identifier 180.255.255.1, local AS number 65100

Neighbor Status Codes: m - Under maintenance

  Description              Neighbor         V  AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc

....

  eOverL-V1                160.255.255.10   4  65100            552       545    0    0 07:40:16 Estab(NotNegotiated)

  eOverL-V2                160.255.255.20   4  65100            555       543    0    0 07:40:16 Estab(NotNegotiated)

And in the following blogs of various L2/L3 vxlan evpn setup, we don't need to touch spine routers anymore

• From control plane point of view, spine1 only reflects BGP EVPN updates among leaf routers w/o VXLAN interface or VRF, which means it doesn't need to understand or import the content. 
• From data plane point of view, spine1 only forwards the IPv4/VXLAN packets by the source/destination address are leafs' loopback address. 

Verifications:

1) BGP EVPN peering to VTEP1/2 are up

bn303-eSpine1#show bgp evpn summary
BGP summary information for VRF default
Router identifier 180.255.255.1, local AS number 65100
Neighbor Status Codes: m - Under maintenance
  Description              Neighbor         V  AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc
  eOverL-V1                160.255.255.10   4  65100            581       573    0    0 00:20:21 Estab   2      2
  eOverL-V2                160.255.255.20   4  65100            585       571    0    0 00:20:21 Estab   2      2