Fady Boules says:

impressive article, I just have one comment, there is an overlapping IP addresses between leaf3, leaf5 and leaf7 on the running interfaces in Configure Underlay Point-to-Point Interfaces section

Same thing on leaf4, leaf6 and leaf8

John says:

You missed the config for varp mac address.

Netmart says:

Hello,
I got stuck at the eVPN BGP setup; evpn neighbors will not come up; underlay eBGP between spien and leaf is established.
Leaf1 is rejecting BGP open message from Spine1 by responding with BGP Notification Message:
Type: Notification Message (3)
Major error Code: Cease (6)
Minor error Code (Cease): Connection Rejected (5)

5 – Connection Rejected
6 – Other Configuration Change

According to RFC RFC4486
If a BGP speaker decides to administratively reset the peering with a neighbor due to a configuration change other than the ones described above, then the speaker SHOULD send a NOTIFICATION message with the Error Code Cease and the Error Subcode “Other Configuration Change“.

Extract of show bgp neighbor output

Spine1:
BGP state is Connect
Peering failure hint: Cease/connection rejected
Number of transitions to established: 0
Last state was Idle
Last event was Start
Last rcvd notification:Cease/connection rejected, Last time 00:01:47, First time 02:07:17, Repeats 45
Last sent socket-error:Connect (Network is unreachable), Last time 02:08:29, First time 02:08:51, Repeats

Leaf1″:
BGP state is Idle, Missing local addresses for activated AFI/SAFIs
Peering failure hint: Missing local addresses for activated AFI/SAFIs
Number of transitions to established: 0
Last state was Idle
Last event was Open
Last sent notification:Cease/connection rejected, Last time 00:36:44, First time 02:08:24, Repeats 3

And spine receives the following Syslog message approximately every 3 minutes:
spine1#Sep 3 03:07:41 spine1 Bgp: %BGP-3-NOTIFICATION: received from neighbor 10.0.250.11 (VRF default AS 65001) 6/5 (Cease/connection rejected) 0 bytes

Config Extract:
spine1
router bgp 65000
router-id 10.0.250.1
no bgp default ipv4-unicast
distance bgp 20 200 200
maximum-paths 4 ecmp 64
neighbor evpn peer-group
neighbor evpn next-hop-unchanged
neighbor evpn update-source Loopback0
neighbor evpn ebgp-multihop 3
neighbor evpn send-community extended
neighbor evpn maximum-routes 12000 warning-only
neighbor 10.0.1.2 remote-as 65001
neighbor 10.0.1.2 maximum-routes 12000
:
neighbor 10.0.250.11 peer-group evpn
neighbor 10.0.250.11 remote-as 65001

address-family evpn
neighbor evpn activate
!
address-family ipv4
neighbor 10.0.1.2 activate
network 10.0.250.1/32

———————————————————
leaf1
router bgp 65001
router-id 10.0.250.11
no bgp default ipv4-unicast
distance bgp 20 200 200
maximum-paths 4 ecmp 64
neighbor evpn peer-group
neighbor evpn remote-as 65000
neighbor evpn update-source Loopback0
neighbor evpn ebgp-multihop 3
neighbor evpn send-community extended
neighbor evpn maximum-routes 12000 warning-only
neighbor underlay_eBGP peer-group
neighbor underlay_eBGP remote-as 65000
neighbor underlay_eBGP maximum-routes 12000 warning-only
neighbor underlay_iBGP peer-group
neighbor underlay_iBGP remote-as 65001
neighbor underlay_iBGP next-hop-self
neighbor underlay_iBGP maximum-routes 12000 warning-only
neighbor 10.0.1.1 peer-group underlay_eBGP
neighbor 10.0.2.1 peer-group underlay_eBGP
neighbor 10.0.3.2 peer-group underlay_iBGP
neighbor 10.0.250.1 peer-group evpn
neighbor 10.0.250.2 peer-group evpn
!
address-family evpn
neighbor evpn activate
!
address-family ipv4
neighbor underlay_eBGP activate
neighbor underlay_iBGP activate
network 10.0.250.11/32

jjfaure says:

Hi David,

I am planning an Arista L3LS using mp-ebgp evpn between spine and leafs, but i need to pass layer 2 connectivity of some vlans between different leafs. I am wondering if you can do it configuring some type of “evpn underaly instance”, and put the vlans in this instance, do you think is it posible?

Do you have some reference about a similar setting?

By the way, your post is really excellent

David says:

I really do like this document & lab. Probably one of the most insightful and helpful documents out there.

I used this in building out this lab. It is a cool script someone showed me that is available with all of Arista’s EOS. In the example below I am just using this in the 3rd octect. I have used it in the 4th octect on the Spines.

Leaf3(config-if-Et1-2)#ip add 10.0.{0,$,2}.5/31
Leaf3(config-if-Et1-2)#show active
interface Ethernet1
no switchport
ip address 10.0.0.5/31
interface Ethernet2
no switchport
ip address 10.0.2.5/31
Leaf3(config-if-Et1-2)#

Spine2(config)#int et1-8
Spine2(config-if-Et1-8)#no swi
Spine2(config-if-Et1-8)#ip add 10.0.2.{0,$,2}/31
Spine2(config-if-Et1-8)

Hope this makes someone’s life a little simpler.