Categories R&S

VPN technologies – MPLS-L3VPN – MP-BGP

In this post, I will focus on configuring MP-BGP which is the protocol used between the PE router.

 

VPN technologies – MPLS-L3VPN – MP-BGP – Theory :

 

This is the link to the Cisco documentation for configuring MPLS-VPN.

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l3_vpns/configuration/15-mt/mp-l3-vpns-15-mt-book.html

 

MP-BGP should be configured between the PE routers and is used to advertised the different VRF routes (that I will create later).

 

VPN technologies – MPLS-L3VPN - MP-BGP

 

VPN technologies – MPLS-L3VPN – MP-BGP – configuration:

 

So we need to configure MP-BGP peering between R5, R6 and R7.

Here is the configuration for R5.

R5(config)#router bgp 65010
R5(config-router)#no bgp default ipv4-unicast
R5(config-router)#
R5(config-router)#neighbor 10.1.1.6 remote-as 65010
R5(config-router)#neighbor 10.1.1.7 remote-as 65010
R5(config-router)#neighbor 10.1.1.6 update-source lo0
R5(config-router)#neighbor 10.1.1.7 update-source lo0
R5(config-router)#
R5(config-router)#address-family vpnv4 unicast
R5(config-router-af)#neighbor 10.1.1.6 activate
R5(config-router-af)#neighbor 10.1.1.7 activate
R5(config-router-af)#neighbor 10.1.1.6 send-community extended
R5(config-router-af)#neighbor 10.1.1.7 send-community extended

 

I use the same configuration on both R6 and R7.

We receive a log message saying both BGP neighbors are UP.

%BGP-5-ADJCHANGE: neighbor 10.1.1.6 Up
%BGP-5-ADJCHANGE: neighbor 10.1.1.7 Up

 

To see the neighbor adjacency, the command is different than the basic BGP command.

R5#sh bgp vpnv4 unicast all sum
BGP router identifier 10.1.1.5, local AS number 65010
BGP table version is 1, main routing table version 1

Neighbor        V           AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.1.1.6        4        65010       4       4        1    0    0 00:01:45        0
10.1.1.7        4        65010       4       4        1    0    0 00:01:43        0

 

That’s an easy configuration.

Using notepad you can do this really quickly.

 

Note that all the specific configuration used for BGP can be combine here. Specially for scalability when you start using several PE routers.

 

In the next post, we will connect customer to the backbone we just configured.

 

Thank you for reading.

 

Have a look at my previous VPN technologies post:

VPN Technologies – MPLS – Label Distribution Protocol

 

 

VPN technologies – MPLS-L3VPN – MP-BGP

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