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Service Provider VPLS InterAS option B - multiple AS

gurfin
Level 1
Level 1

Hello everyone,

First forum post! I am new to the world of L2VPN and I am in need of some help. 

I have a MPLS WAN that is built on Cisco ISR routers. One site is the main site, in the diagram shown as AS1 which should act as the AS which interconnects all other sites. The "hub" site has a standard SP MPLS core using LDP for label signaling. My goal is to be able to use VPLS to build dynamic L2 tunnels between the devices, without using LDP. I have L3VPNs up and running using BGP label signaling on the MPLS InterAS links according to Option B, that is I am only configuring "mpls bgp forwarding" and not "mpls ip" on the interconnecting interfaces.

How would an example configuration look like which achives the desired network topology of the diagram?

 

I have tried to follow this documentation but since I am not using LDP at all this is not completely applicable to my topology:

https://www.cisco.com/c/en/us/td/docs/routers/ios/config/17-x/mpls/b-mpls/m-mp-vpls-bgp-sig-inter-as-option-b.pdf

 

JosefDahlstrom_0-1719353953490.png

 

Any help or pointers are appreciated!

2 Replies 2

How traffic encapsulate and pass through SP core if you dont use ldp?

I dont think it work.

MHM

Thank you for your response! However, I am not sure I quite understand.

Isn't LDP only used for label control-plane, not data-plane? That is to exchange information regarding which labels should be used. The encapsulation is still MPLS. And to be clear, each AS acts as it's own system, with an isolated LDP domain. IntraAS is using LDP for where this is relevant, while InterAS does not run LDP, but rather uses BGP for signaling which labels to use. As stated, I am quite new to InterAS world, especially for L2VPNs as this is my first attempt to get VPLS running between AS, so please excuse me if this is incorrect. 

IntraAS uses "mpls ip" on iBGP links.

InterAS uses "mpls bgp forwarding" on eBGP links.