Cisco NX-OS: VXLAN Symmetric Routing

EVPN Integrated Routing and Bridging (IRB) has two options:

Asymmetric IRB (increased ARP cache and CAM table sizes and control plane scaling issue)
Symmetric IRB

Symmetric IRB

Ingress VTEP does both L2 and L3 lookup
Egress VTEp does both L3 and L2 lookup
=> Bridge - Route - Route - Bridge

L3 VNI should be configured on all VTEPS, L2 VNIs only where local ports exist

N5K1 Configuration

fabric forwarding anycast-gateway-mac 1234.1234.1234  
!  
! VLAN to VNI mappings  
vlan 10  
   vn-segment 101010  
vlan 30 
   vn-segment 303030  
!  
! VRF to VNI mapping  
vrf context CUSTOMER1  
   vni 303030  
   rd auto  
   address-family ipv4 unicast  
       route-target both auto  
     route-target both auto evpn 
! advertise to both ipv4 unicast and l2vpn evpn  
!  
interface Vlan10  
   no shutdown  
   vrf member CUSTOMER1  
   ip address 10.10.10.1/24  
   fabric forwarding mode anycast-gateway  
!  
! Shared L3 VNI  
interface Vlan30  
   no shutdown  
   vrf member CUSTOMER1  
   ip forward  
!  
interface nve1  
   no shutdown  
   host-reachability protocol bgp  
   source-interface loopback0  
   member vni 101010  
       mcast-group 228.7.7.8  
   member vni 303030 associate-vrf  
!  member vni 303030 associate-vrf <---- L3 segment_  
!  
router bgp 1  
   log-neighbor-changes  
   neighbor 1.1.1.3  
       remote-as 1  
       update-source loopback0  
       address-family l2vpn evpn  
           send-community extended  
   neighbor 1.1.1.4  
       remote-as 1  
       update-source loopback0  
       address-family l2vpn evpn  
           send-community extended  
   vrf CUSTOMER1  
       address-family ipv4 unicast  
           redistribute direct route-map PERMIT  
!  
evpn  
   vni 101010 l2  
       rd auto  
       route-target import auto  
        route-target export auto

N5K2 Configuration

fabric forwarding anycast-gateway-mac 1234.1234.1234  
!  
! VLAN to VNI mappings  
vlan 20  
   vn-segment 202020  
vlan 30  
   vn-segment 303030  
!  
! VRF to VNI mapping  
vrf context CUSTOMER1  
   vni 303030  
   rd auto  
   address-family ipv4 unicast  
       route-target both auto  
     route-target both auto evpn
! advertise to both ipv4 unicast and l2vpn evpn  
!  
interface Vlan20  
   no shutdown  
   vrf member CUSTOMER1  
   ip address 20.20.20.1/24  
   fabric forwarding mode anycast-gateway  
!  
! Shared L3 VNI  
interface Vlan30  
   no shutdown  
   vrf member CUSTOMER1  
   ip forward  
!  
interface nve1  
   no shutdown  
   host-reachability protocol bgp  
   source-interface loopback0  
   member vni 202020  
       mcast-group 228.7.7.9  
   member vni 303030 associate-vrf 
!  member vni 303030 associate-vrf <---- L3 segment 
!  
router bgp 1  
   log-neighbor-changes  
   neighbor 1.1.1.3  
       remote-as 1  
       update-source loopback0  
       address-family l2vpn evpn  
           send-community extended  
   neighbor 1.1.1.4  
       remote-as 1  
       update-source loopback0  
       address-family l2vpn evpn  
           send-community extended  
   vrf CUSTOMER1  
       address-family ipv4 unicast  
           redistribute direct route-map PERMIT  
!  
evpn  
   vni 202020 l2  
       rd auto  
       route-target import auto  
        route-target export auto