BGP/EVPN Underlay Example

Spine 1

router bgp 65000
   router-id 5.5.5.5
   no bgp default ipv4-unicast
   distance bgp 20 200 200
   maximum-paths 3 ecmp 3
   neighbor 10.10.1.2 remote-as 65001
   neighbor 10.10.1.2 description Leaf1
   neighbor 10.10.1.2 maximum-routes 12000
   neighbor 10.10.1.6 remote-as 65001
   neighbor 10.10.1.6 description Leaf2
   neighbor 10.10.1.6 maximum-routes 12000
   neighbor 10.10.1.10 remote-as 65002
   neighbor 10.10.1.10 description Leaf3
   neighbor 10.10.1.10 maximum-routes 12000
   neighbor 10.10.1.14 remote-as 65003
   neighbor 10.10.1.14 description Leaf4
   neighbor 10.10.1.14 maximum-routes 12000


   address-family ipv4
   neighbor 10.10.1.2 activate
   neighbor 10.10.1.6 activate
   neighbor 10.10.1.10 activate
   neighbor 10.10.1.14 activate
   network 5.5.5.5/32

Leaf 1

router bgp 65001
   router-id 1.1.1.1
   no bgp default ipv4-unicast
   distance bgp 20 200 200
   maximum-paths 3 ecmp 3
   neighbor 10.10.1.1 remote-as 65000
   neighbor 10.10.1.1 maximum-routes 12000
   neighbor 10.10.2.1 remote-as 65000
   neighbor 10.10.2.1 maximum-routes 12000
   neighbor 172.16.4.2 remote-as 65001			//iBGP Neighborship
   neighbor 172.16.4.2 next-hop-self
   neighbor 172.16.4.2 maximum-routes 12000

   address-family ipv4
      neighbor 10.10.1.1 activate
      neighbor 10.10.2.1 activate
      neighbor 172.16.4.2 act
      network 1.1.1.1/32

Verification

• Ensure that BGP neighborships are formed. Spines should see all the leaf’s, and leaf’s should see the spines and MLAG partners if an mlag pair.

show ip bgp summ

Leaf2 Verification

Leaf2#show ip bgp summ
BGP summary information for VRF default
Router identifier 2.2.2.2, local AS number 65001
Neighbor Status Codes: m - Under maintenance
  Neighbor   V AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc PfxAdv
  10.10.1.5  4 65000            367       368    0    0 05:02:17 Estab   3      3      4
  10.10.2.5  4 65000            373       368    0    0 05:02:12 Estab   3      3      4
  172.16.4.1 4 65001             14        15    0    0 00:00:19 Estab   5      5      5
Leaf2#

Spine1 Verification

Spine1(config-router-bgp-af)#show ip bgp summ
BGP summary information for VRF default
Router identifier 5.5.5.5, local AS number 65000
Neighbor Status Codes: m - Under maintenance
  Description              Neighbor   V AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc PfxAdv
  Leaf1                    10.10.1.2  4 65001            377       373    0    0 05:03:15 Estab   2      2      4
  Leaf2                    10.10.1.6  4 65001            369       369    0    0 05:03:44 Estab   2      2      4
  Leaf3                    10.10.1.10 4 65002            370       368    0    0 05:04:38 Estab   1      1      4
  Leaf4                    10.10.1.14 4 65003            372       373    0    0 05:04:35 Estab   1      1      4
Spine1(config-router-bgp-af)#