Perform the following steps to configure unnumbered BGP for the nondefault (tenant) VRF:
- Specify the router AS number and enter BGP configuration mode for the VRF tenant by running the
router bgp
AS_number
vrf
vrf_name
command. - For the router ID, specify the IP address that is configured on interface Loopback 0.
- Enter the address-family ipv4 unicast command.
- Specify the redistribute connected command to redistribute IPv4 routes from physically connected interfaces.
- Configure the maximum number of eBGP routes that can be used to forward packets over multiple paths to a neighbor.
- Enter the address-family l2vpn evpn command.
- Advertise IPv4 routes.
- Enable duplicate address detection. Note: The following steps are for connection to the external network. In the configuration example used in this guide, the uplinks are L3 with unnumbered BGP.
- Create a peer group for the external switch connections. It is named LEGACY in this example.
- Configure a remote autonomous system to exchange routes through eBGP. The remote-as external command is required for unnumbered BGP.
- Configure the time (in seconds) between sending keepalive messages to a BGP neighbor, and the wait time to receive a keepalive message before considering a BGP peer to be dead.
- Configure the route advertisement interval between sending BGP route updates to neighbors.
- Enable bidirectional forwarding detection (BFD). BFD rapidly detects communication failures between two adjacent routers.
- The capability extended-nexthop command is required for unnumbered BGP. It enables BGP to negotiate the extended next hop capability with a peer.
- Enter the address-family ipv4 unicast command, and then activate.
- Put the interfaces that are connected to the external switches in the peer group.
Leaf1A Leaf1B router bgp 65101 vrf VrfTenant1
router-id 10.1.1.1
!
address-family ipv4 unicast
redistribute connected
maximum-paths 2
!
address-family l2vpn evpn
advertise ipv4 unicast
dup-addr-detection
peer-group LEGACY
remote-as external
timers 3 9
advertisement-interval 5
bfd
capability extended-nexthop
!
address-family ipv4 unicast
activate
!
neighbor interface Eth1/47
peer-group LEGACY
!
neighbor interface Eth1/48
peer-group LEGACYrouter bgp 65101 vrf VrfTenant1
router-id 10.1.1.2
!
address-family ipv4 unicast
redistribute connected
maximum-paths 2
!
address-family l2vpn evpn
advertise ipv4 unicast
dup-addr-detection
peer-group LEGACY
remote-as external
timers 3 9
advertisement-interval 5
bfd
capability extended-nexthop
!
address-family ipv4 unicast
activate
!
neighbor interface Eth1/47
peer-group LEGACY
!
neighbor interface Eth1/48
peer-group LEGACY
- Configure a remote autonomous system to exchange routes through eBGP.