I’m looking forward to setting up a Nexus 9k Solution, L3 using VXLAN BGP EVPN Topology Dual DataCentre configuration. Aiming for a Live/Live Core between the two. Only caveat is we will stick to L2 supporting the Edge, for Internet and IPWAN connections using traditional technologies such as HSRP.
VXLAN BGP EVPN…..Configuration guide
Some information on how to configure multiprotocol extended Border Gateway Protocol (MP-EBGP). Extended BGP allows for the transport of routing information for multiple network layer protocols IPv6, VPNv4, and others. MP-BGP allows you to have a unicast routing topology different from a multicast routing topology, which helps to control the network and resources.
In this example, the R1 and R3 routers are configured to be in AS 5500 forming iBGP. The R2 router is configured to be in AS 6500. The R1 and R2 routers communicate with each other using MP-EBGP.
From the below you can see the next hop for 192.168.0.0 network is 10.0.0.2 which is outsite of 65000 AS, and router jazz doesn’t have a route to it. BGP will not put 192.168.0.0 into routing table because it doesn’t know how to reach next hop, you can see this below:
By adding the next-hop-self command on the router owen it will change the next-hop attribute for external networks that will be advertised to the router Jazz:
owen(config-router)#neighbour 10.0.1.2 next-hop-self
This changes the next hop attribute from 10.0.0.2 to be 10.0.1.1 on the router owen
from Jazz you can now ping (192.168.0.1) on Jules.
Basic config for a BGP Peer Group within an AS 123 and some iBGP routers. The config uses peer-group and route reflectors which saves you a lot of configuration on all the iBGP devices.
IP Routing: BGP Configuration Guide, Cisco IOS Release 15M&T