Cisco Catalyst 2960 Network Switch Configuration Guide: BGP EVPN VXLAN Fabric (EN)

Deployment Scenarios for Spine Switches and Leaf Switches in a BGP EVPN VXLAN Fabric

Configuring Spine Switches in a BGP EVPN VXLAN Fabric Information About Spine Switches in a BGP EVPN VXLAN Fabric, on page 1 Configuration Examples for Spine Switches in a BGP EVPN VXLAN Network, on page 2 Information About Spine Switches in a BGP EVPN VXLAN Fabric Spine switches in a BGP EVPN VXLAN fabric act as the connecting nodes between all the leaf switches or VTEPs. They form the backbone of the EVPN VXLAN network and forward traffic between the leaf switches. Each leaf switch is connected to each spine switch in the network. Spine switches enable redundancy within the network and provide multiple paths for VTEPs to forward traffic to each other.

Spine switches in an EVPN VXLAN network are part of the underlay network and transport the VXLAN-encapsulated packets. When deployed as border nodes, spine switches connect the network with an external network and allow movement of traffic. In a BGP EVPN VXLAN fabric, spine switces can also be deployed as route reflectors. Deployment Scenarios for Spine Switches and Leaf Switches in a BGP EVPN VXLAN Fabric Spine switches and leaf switches in a BGP EVPN VXLAN fabric can be deployed in the following ways:

• Spine Switches and Leaf Switches in the Same Autonomous System • Spine Switches in One Autonomous System and the Leaf Switches in a Different Autonomous System • Spine Switches in One Autonomous System and Each Leaf Switch in a Different Autonomous System Spine Switches and Leaf Switches in the Same Autonomous System In this scenario, all the devices in the EVPN VXLAN network are in the same autonomous system. The spine switches function as BGP route reflectors and anycast rendezvouz points (RPs). Internal Border Gateway Protocol (iBGP) is used to establish peering between the spine switches, and between the spine and leaf switches.

See Configuration Example-Spine and Leaf Switches in the Same Autonomous System, on page 2 for a sample topology and configuration. Configuring Spine Switches in a BGP EVPN VXLAN Fabric 1

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Configuration Example-Spine and Leaf Switches in the Same Autonomous System

Spine Switches in One Autonomous System and the Leaf Switches in a Different Autonomous System In this scenario, all the leaf switches are in a single autonomous system that is different from the autonomous system of the spine switches. The spine switches function as BGP route servers. iBGP is used to establish peering between the spine switches. eBGP is used to establish peering between the spine and leaf switches. See Configuration Example-Spine and Leaf Switches are in Different Autonomous Systems, on page 19 for a sample topology and configuration.

Spine Switches in One Autonomous System and Each Leaf Switch in a Different Autonomous System In this scenario, each leaf switch is in its own individual autonomous system that is different from the autonomous system of the spine switches. The spine switches function as BGP route servers. iBGP is used to establish peering between the spine switches. eBGP is used to establish peering between the spine and leaf switches. See Configuration Example-Each Leaf Switch in a Different Autonomous System, on page 37 for a sample topology and configuration.

Configuration Examples for Spine Switches in a BGP EVPN VXLAN Network This section provides configuration examples for spine switches for the different deployments of spine and leaf switches in a BGP EVPN VXLAN fabric. Configuration Example-Spine and Leaf Switches in the Same Autonomous System This section provides an example to show how spine switches are configured in a BGP EVPN VXLAN fabric using iBGP when the spine switches and leaf switches are in the same autonomous system. The example shows how to configure spine switches and verify the configuration for the topology shown below:

Configuring Spine Switches in a BGP EVPN VXLAN Fabric Configuration Examples for Spine Switches in a BGP EVPN VXLAN Network Configuring Spine Switches in a BGP EVPN VXLAN Fabric 2

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Configuration Example-Spine and Leaf Switches in the Same Autonomous System

Figure 1: BGP EVPN VXLAN Fabric with the Spine Switches and Leaf Switches in the Same Autonomous System The topology shows an EVPN VXLAN network with two leaf switches (VTEP 1 and VTEP 2) and two spine switches (Spine Switch 1 and Spine Switch 2). The entire BGP EVPN VXLAN fabric (which includes Spine Switch 1, Spine Switch 2, Leaf Switch 1, and Leaf Switch 2) is in autonomous system AS65001. Anycast RP is configured on both the spine switches. Spine Switch 1 and Spine Switch 2 are not route reflector clients to each other. Multicast Source Discovery Protocol (MSDP) is configured between Spine Switch 1 and Spine Switch 2 for source synchronization.

Protocol Independent Multicast (PIM) is enabled on the interfaces that connect leaf switches and spine switches. Static RP is configured in the network and the underlay network uses multicast forwarding mechanism to forward BUM traffic. The following tables provide sample configurations for the devices in the topology above. Configuring Spine Switches in a BGP EVPN VXLAN Fabric Configuration Example-Spine and Leaf Switches in the Same Autonomous System Configuring Spine Switches in a BGP EVPN VXLAN Fabric 3

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Configuration Example-Spine and Leaf Switches in the Same Autonomous System

Table 1: Configuring Spine Switch 1 and Spine Switch 2 using iBGP when the Spine Switches and the Leaf Switches are in the same Autonomous System Configuring Spine Switches in a BGP EVPN VXLAN Fabric Configuration Example-Spine and Leaf Switches in the Same Autonomous System Spine Switch 1 Spine Switch 2 Spine-01# show running-config hostname Spine-01 ! ip routing ! ip multicast-routing ! interface Loopback0 ip address 172.16.255.1 255.255.255.255 ip ospf 1 area 0 ! interface Loopback1 ip address 172.16.254.1 255.255.255.255 ip ospf 1 area 0 ! interface Loopback2 ip address 172.16.255.255 255.255.255.255 ip pim sparse-mode ip ospf 1 area 0 !

interface GigabitEthernet1/0/1 no switchport ip address 172.16.13.1 255.255.255.0 ip pim sparse-mode ip ospf network point-to-point ip ospf 1 area 0 ! interface GigabitEthernet1/0/2 no switchport ip address 172.16.14.1 255.255.255.0 ip pim sparse-mode ip ospf network point-to-point ip ospf 1 area 0 ! router ospf 1 router-id 172.16.255.1 ! router bgp 65001 template peer-policy RR-PP route-reflector-client send-community both exit-peer-policy ! template peer-session RR-PS remote-as 65001 update-source Loopback0 exit-peer-session !

bgp router-id 172.16.255.1 bgp log-neighbor-changes no bgp default ipv4-unicast neighbor 172.16.255.3 inherit peer-session RR-PS neighbor 172.16.255.4 inherit peer-session RR-PS ! address-family ipv4 exit-address-family ! Spine-02# show running-config hostname Spine-02 ! ip routing ! ip multicast-routing ! interface Loopback0 ip address 172.16.255.2 255.255.255.255 ip ospf 1 area 0 ! interface Loopback1 ip address 172.16.254.2 255.255.255.255 ip ospf 1 area 0 ! interface Loopback2 ip address 172.16.255.255 255.255.255.255 ip pim sparse-mode ip ospf 1 area 0 !

interface GigabitEthernet1/0/1 no switchport ip address 172.16.23.2 255.255.255.0 ip pim sparse-mode ip ospf network point-to-point ip ospf 1 area 0 ! interface GigabitEthernet1/0/2 no switchport ip address 172.16.24.2 255.255.255.0 ip pim sparse-mode ip ospf network point-to-point ip ospf 1 area 0 ! router ospf 1 router-id 172.16.255.2 ! router bgp 65001 template peer-policy RR-PP route-reflector-client send-community both exit-peer-policy ! template peer-session RR-PS remote-as 65001 update-source Loopback0 exit-peer-session !

bgp router-id 172.16.255.2 bgp log-neighbor-changes no bgp default ipv4-unicast neighbor 172.16.255.3 inherit peer-session RR-PS neighbor 172.16.255.4 inherit peer-session RR-PS ! address-family ipv4 exit-address-family ! Configuring Spine Switches in a BGP EVPN VXLAN Fabric 4

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