10-19-2017 06:19 AM - edited 03-05-2019 09:19 AM
Hello,
My company has recently purchased a mpls solution that configures the WAN and then redistributes back into the LAN at an ASR. On our core are 3 existing vrfs, that the mpls will need to integrate with. The main vrf has BGP running within it - so presumably I need to setup a BGP peering and that will advertise the routes back.
The other two vrf don't have any dynamic routing - these vrfs are flat layer 2 networks that have been rolled out across the network as layer 2 vpls solutions. The intention was that I would retain the same ip subnets to the new mpls but I'm confused how best to integrate the old flat network with the new layer 3 solution. How would I best advertise routes between the ASR and the core for these vrfs. Any advise would be much appreciated.
Steve
10-19-2017 07:55 AM
Hi
All of the 3 VRFs are being advertised through the MP-BGP?
10-19-2017 02:42 PM
Yes that's right, though I haven't got access to the configuration on the router.
10-19-2017 02:52 PM - edited 10-19-2017 03:54 PM
Hi,
Basically each VRF has its own routing table, so if you want to be able to reach the subnets from each other, you can import the route-targets from each other, for example:
ip vrf A
rd 1:1
route-target export 1:1
route-target import 1:1
route-target import 2:2
route-target import 3:3
ip vrf B
rd 2:2
route-target export 2:2
route-target import 2:2
route-target import 1:1
route-target import 3:3
ip vrf C
rd 3:3
route-target export 3:3
route-target import 3:3
route-target import 1:1
route-target import 2:2
Or
ip vrf A
rd 1:1
route-target export 1:1
route-target import 3:3
ip vrf B
rd 2:2
route-target export 2:2
route-target import 3:3
ip vrf C (MAIN)
rd 3:3
route-target export 3:3
route-target import 3:3
route-target import 1:1
route-target import 2:2
10-20-2017 03:33 AM
Thanks for the information, can you just clarify that the routes will appear without any additional configuration. Will I need to setup an instance of BGP/ or another dynamic routing protocol on the vrfs that currently don't have any routing setup to see those routes.
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