L3VPN with EVPN-VXLAN instead of MPLS in Arista

In this post, we will talk about L3VPN with EVPN-VXLAN in Arista. As you know, especially Service Providers use MPLS to provide L3VPN service. However, you can continue via VXLAN technology in your Service Provide or DC network. With the aid of Route-Types, VXLAN can build L3VPN with EVPN-VXLAN instead of using MPLS in Arista. Route-Type 5 advertises VRF information in EVPN technology. We will show config sample below.

Topology

In this network, we will use Leaf-Spine architecture. Underlay will use EBGP and Leafs are MLAG peer.

Technical Explanation

In this topology, CUSTOMER has vrf in leaf1-2 with VLAN 100. Also CUSTOMER has 101 VLAN on Leaf3-4 in VRF. They are in different subnet and we will try to communicate them via VXLAN not MPLS technology.

LEAF1-2 are under AS65101, LEAF3-4 are under AS65102, SPINES are AS65000. There is EBGP IPV4 and EVPN neighborship between SPINE and LEAFS. This earlier post gives detail about EVPN-VXLAN

We will use EVPN-VXLAN technology and EVPN will advertise Route-Type -5, that is ip-prefixes. VLAN will be encapsulated with VNI 1001. So routes of VRFs will be mapped to VNI 1001 via VXLAN. As you see there is no MPLS Label.

VRF AND VXLAN Config for CUSTOMER

LEAF1-2 Config

interface Vxlan1
  vxlan source-interface Loopback1
  vxlan udp-port 4789
  vxlan vrf CUSTOMER vni 1001

router bgp 65100
 vrf CUSTOMER
      rd 10.10.10.1:100
      route-target import evpn 65101:100
      route-target export evpn 65100:100
      redistribute connected

interface Vlan100
   vrf CUSTOMER
   ip address 10.100.100.2/24------>can be VRRP or VARP

LEAF3-4 Config

interface Vxlan1
   vxlan source-interface Loopback1
   vxlan udp-port 4789
   vxlan vrf CUSTOMER vni 1001

router bgp 65101
   vrf CUSTOMER
      rd 10.10.10.3:100
      route-target import evpn 65100:100
      route-target export evpn 65101:100
      redistribute connected

interface Vlan100
   vrf CUSTOMER
   ip address 10.101.101.2/24-------->can be VRRP or VARP 

OUTPUTS

LEAF-3#SHow bgp  evpn  summary ---------> NEIGHBORSHIP WITH SPINES 
BGP summary information for VRF default
Router identifier 10.10.10.3, local AS number 65101
Neighbor Status Codes: m - Under maintenance
  Neighbor         V  AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc
  10.10.10.254     4 65000           1352      1327    0    0 09:02:04 Estab   6      6
  10.10.10.255     4 65000           1341      1329    0    0 17:13:39 Estab   6      6

LEAF-3#SHow  bgp  neighbors 10.10.10.254 evpn  routes-------ROUTE-TYPE 5 received from peer
BGP routing table information for VRF default
Router identifier 10.10.10.3, local AS number 65101
Route status codes: s - suppressed, * - valid, > - active, E - ECMP head, e - ECMP
                    S - Stale, c - Contributing to ECMP, b - backup
                    % - Pending BGP convergence
Origin codes: i - IGP, e - EGP, ? - incomplete
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop

          Network                Next Hop              Metric  LocPref Weight  Path

 *  ec   RD: 10.10.10.1:100 ip-prefix 10.100.100.0/24
                                 1.1.1.1               -       100     0       65000 65100 i
 *  ec   RD: 10.10.10.2:100 ip-prefix 10.100.100.0/24
                                 1.1.1.1               -       100     0       65000 65100 i

LEAF-3#show  ip route  vrf  CUSTOMER------ROUTE-TABLE OF VRF,check BGP routes are assigned to vtep and VNI, not MPLS Label

VRF: CUSTOMER
Codes: C - connected, S - static, K - kernel, 
       O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
       E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
       N2 - OSPF NSSA external type2, B - BGP, B I - iBGP, B E - eBGP,
       R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
       O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
       NG - Nexthop Group Static Route, V - VXLAN Control Service,
       DH - DHCP client installed default route, M - Martian,
       DP - Dynamic Policy Route, L - VRF Leaked,
       RC - Route Cache Route

Gateway of last resort is not set

 B E      10.100.100.0/24 [20/0] via VTEP 1.1.1.1 VNI 1001 router-mac 50:00:01:f9:f3:5d
                                 via VTEP 1.1.1.1 VNI 1001 router-mac 50:00:01:84:c6:28
 C        10.101.101.0/24 is directly connected, Vlan101