Router-Cake

Lenny Allen Blottin III

Building BGP EVPN-VxLAN in Datacenter in EVE-NG

A while back, a Network Architect told me about a blog by Satish Patel that inspired him for the design of a Spine-Leaf network. In this post, I’m going to use his blog steps and build my own in EVE-NG lab and document the steps here: UPDATE 5/31/2025: I am keeping all of the configs…

LennyDoesIT
3–5 minutes

A while back, a Network Architect told me about a blog by Satish Patel that inspired him for the design of a Spine-Leaf network. In this post, I’m going to use his blog steps and build my own in EVE-NG lab and document the steps here:

UPDATE 5/31/2025: I am keeping all of the configs on Github here under the “ansible/golden configs” directory: https://github.com/Lenniusce/Network-Automation

These are actively getting pushed as they change. Look for future blog posts for developments.

First, we need to setup EVE-NG:

Very cool, with the Refplat images loaded, we are going to focus on the Nexus 9000v image.

I’m also using EVE-NG lab to build EVPN-VxLAN fabric. I am using Cisco Nexus 9K Switches to build fabric. The versions here:

  • EVE-NG version: 6.2.0-4
  • QEMU version: 2.4.0
  • nxosv9k-9300v-9.3.8

Physical Topology

Here is the end result of cabling up the lab:

NameFunction
ISP-01First Router to mimic ISP
ISP-02Second Router to mimic ISP
SPINE01Aggregate switch for Leafs
SPINE02Aggregate switch for Leafs
ASAv-01First Firewall, Eventually to be converted to PANOS
ASAv-02Standby Firewall, Eventually to be converted to PANOS
R1-TOR01Leaf switch, top of rack
R1-TOR02Leaf switch, top of rack
R2-TOR01Leaf switch, top of rack
R2-TOR02Leaf switch, top of rack
R3-TOR01Leaf switch, top of rack
R3-TOR02Leaf switch, top of rack
VPCSingle Workstation
VPCSingle Workstation

Configuration Building

Underlay – BGP/OSPF – What this means is the is the network protocols that provides basic routing and packet forwarding.

Overlay – VXLAN – The “overlay” is a virtual network built on top of the underlay, using tunneling protocols to create virtual connections.

SPINE01 Configuration Notes:

!! We define the virtual device context (VDC) parameters !!
vdc SPINE01 id 1
  limit-resource vlan minimum 16 maximum 4094
  limit-resource vrf minimum 2 maximum 4096
  limit-resource port-channel minimum 0 maximum 511
  limit-resource m4route-mem minimum 58 maximum 58
  limit-resource m6route-mem minimum 8 maximum 8
!! Here we enable the features for BGP, OSPF, Multicast !!
nv overlay evpn
feature ospf
feature bgp
feature pim
!! PIM Rendezvous Point and group-list are defined !!
ip pim rp-address 10.255.0.123 group-list 239.0.0.0/8
ip pim ssm range 232.0.0.0/8
ip pim anycast-rp 10.255.0.123 10.255.0.1
ip pim anycast-rp 10.255.0.123 10.255.0.2 
!! Interfaces connecting to the TORs need OSPF point-to-point defined as well as the pim sparse-mode enabled for multicast traffic !!
interface Ethernet1/1
  description R1-TOR01
  no switchport
  mtu 9216
  medium p2p
  ip unnumbered loopback0
  ip ospf network point-to-point
  ip router ospf UNDERLAY-NET area 0.0.0.0
  ip pim sparse-mode
  no shutdown
!! Loopback 0 is used for the OSPF overlay !!
interface loopback0
  description ** RID/BGP Overlay **
  ip address 10.255.0.1/32
  ip router ospf UNDERLAY-NET area 0.0.0.0
  ip pim sparse-mode
!! Loopback 1 is our RP !!
interface loopback1
  description ** Anycast-RP address **
  ip address 10.255.0.123/32
  ip router ospf UNDERLAY-NET area 0.0.0.0
  ip pim sparse-mode
!! OSPF Configuration on the SPINE !!
router ospf UNDERLAY-NET
  router-id 10.255.0.1
  log-adjacency-changes
!! BGP Configuration has each neighbor defined as well as the template for each neighbor as "VXLAN_LEAF" !!
router bgp 65001
  router-id 10.255.0.1
  log-neighbor-changes
  template peer VXLAN_LEAF
    remote-as 65001
    update-source loopback0
    address-family ipv4 unicast
    address-family l2vpn evpn
      send-community
      send-community extended
      route-reflector-client
  neighbor 10.255.1.1
    inherit peer VXLAN_LEAF
    description R1-TOR01
  neighbor 10.255.1.2
    inherit peer VXLAN_LEAF
    description R1-TOR02
  neighbor 10.255.1.11
    inherit peer VXLAN_LEAF
    description R2-TOR01
  neighbor 10.255.1.12
    inherit peer VXLAN_LEAF
    description R2-TOR02
  neighbor 10.255.1.21
    inherit peer VXLAN_LEAF
    description R3-TOR01
  neighbor 10.255.1.22
    inherit peer VXLAN_LEAF
    description R3-TOR02

TOR Configuration Notes:

!! We define the virtual device context (VDC) parameters !!
vdc SPINE01 id 1
  limit-resource vlan minimum 16 maximum 4094
  limit-resource vrf minimum 2 maximum 4096
  limit-resource port-channel minimum 0 maximum 511
  limit-resource m4route-mem minimum 58 maximum 58
  limit-resource m6route-mem minimum 8 maximum 8
!! We have more services and features to enable, specifically for evpn and overlay features we didnt have on the Spine !!
feature scp-server
feature ngmvpn
nv overlay evpn
feature ospf
feature bgp
feature pim
feature fabric forwarding
feature interface-vlan
feature vn-segment-vlan-based
feature nv overlay
feature vpc
feature lacp
feature bfd
!! Anycast gateway mac address defined for VXLANs !!
fabric forwarding anycast-gateway-mac 0000.1111.1111
ip pim rp-address 10.255.0.123 group-list 239.0.0.0/8
ip pim ssm range 232.0.0.0/8
!! Route map to permit all traffic for BGP !!
route-map DIRECT-PERMIT-ALL permit 10
  description route-map for bgp
!! Most important configuration or tenant traffic, this is the VRF which servers, laptops, etc use to pass traffic over the datacenter !!
vrf context VXLANS
  description VRF_VXLANS
  vni 10555
!! The RP being defined !!
ip pim rp-address 10.69.69.254 group-list 224.0.0.0/4
!! vPC Domain Configuration:
!! - vpc domain 1: Defines the vPC domain ID; must match on both peers.
!! - peer-switch: Allows both switches to act as the STP root for VLANs.
!! - role priority 10: Sets the vPC role priority (lower = preferred primary).
!! - peer-keepalive destination 172.30.0.22 source 172.30.0.21:
!!     Configures the out-of-band peer-keepalive link to monitor peer liveliness.
!! - delay restore 90: Delays vPC port recovery for 90 seconds after peer comes back online.
!! - peer-gateway: Enables both switches to respond to the vPC virtual MAC as default gateway.
!! - delay restore interface-vlan 30: Adds restore delay specifically for SVI 30.
!! - ipv6 nd synchronize: Synchronizes IPv6 ND table between vPC peers.
!! - ip arp synchronize: Synchronizes IPv4 ARP table between vPC peers.
vpc domain 1
  peer-switch
  role priority 10
  peer-keepalive destination 172.30.0.22 source 172.30.0.21
  delay restore 90
  peer-gateway
  delay restore interface-vlan 30
  ipv6 nd synchronize
  ip arp synchronize
!! Underlay backup for VPC link !!
interface Vlan444
  description ** Underlay Backup over vPC Peer-Link **
  no shutdown
  no ip redirects
  ip address 192.168.0.1/30
  no ipv6 redirects
  ip ospf network point-to-point
  ip router ospf UNDERLAY-NET area 0.0.0.0
  ip pim sparse-mode
!! L3 VNI !!
Notes on config here

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