Bgp Front Door Vrf
In order to understand the use of front door vrfs let us use a simple topology as below where we will create a simple gre tunnel between r1 and r4.
Bgp front door vrf. This includes things such as the correct tunnel configuration routing configuration using bgp as the protocol of choice as well as nat toward an upstream provider and front door vrf s in order to implement a default route on both the hub and the spokes and last but not least a newer feature namely per tunnel qos using nhrp. Interface gig0 ip vrf forwarding front door ip address x x x x y y y y then you can create a default route in that vrf used for establishing the tunnels. Both r1 and r4 will learn about the tunnel destination address via underlying protocol i e. Ip route vrf front door 0 0 0 0 0 0 0 0 z z z z you have to tell the tunnel interface to use the new vrf for establishing the tunnel.
As you can see we did not move the tunnel11 interface from the global routing table to the routing table for vrf pipe. Stated another way the local endpoint of the ipsec tunnel belongs to the fvrf while the source and destination addresses of the inside packet belong to the ivrf. However another way to use bgp in the enterprise is on a single router supporting networking virtualization with vrf lite. Modify the tunnel interface to stitch the tunnel to the front door vrf.
Vrf lite is also known as multi vrf. The key must be defined in a keyring. The crypto isakmp key command doesn t support vrfs. All we did is stitch them together.
Ospf in our case. Stated another way the local endpoint of the ipsec tunnel belongs to the fvrf while the source and destination addresses of the inside packet belong to the ivrf the unprotected lan side. Vrf domain called the front door vrf fvrf while the inner protected ip packet belongs to another domain called the inside vrf ivrf. Crypto keyring dmvpn vrf dmvpn pre shared key address 0 0 0 0 0 0 0 0 key cisco when you are using a front door vrf you can t define the key using the old crypto isakmp key command.
I just did your topology on a lab and had 0 issues. Bgp has also been used in the core of large enterprise environments as a tool to enhance network scalability and support separate administrative control domains.