MPLS for Private WAN between 2 service provider

[vpollifrone]

Hello All,

we are current running an MPLS network from service provider 1 across our Branch office network. we need moe redudnancy and are looking to add another MPLS cloud from service provider 2. How would we integrate service provider 2 onto the same Cisco routers due to the fact the only 1 BGP AS can run inside the router? Any info would be appreciated.

[Reza Sharifi]

Hi,

You only have one AS for your network that peers with 2 different service providers. You don't need a second as because you are peering with a second ISP.  All you need on you site is one.

here is an example

your AS is 1234

router bgp 1234

no synchronization

bgp log-neighbor-changes

neighbor 172.16.1.1 remote-as 200 (isp-1)

neighbor 192.168.1.1 remote-as 100 (isp-2)

no auto-summary

HTH

[vpollifrone]

Hi,

I appreciate the feedback. I understand what you are stating above, however here is my dilemma. ISP 1 provided me with a private BGP AS# 65XXX to use for my locations. Provider 2 states that they cannot use the same private BGP AS# 65XXX within their MPLS network. How do I get around this without using seperate routers at each site?.

[Vaibhava Varma · Accepted solution]

Hi vpollifrone

For this Scenario whereby we have a single router and already peered with one ISP on private AS and now need peering with another ISP on Public AS we can make use of the "local-as" feature provided we own a Public AS...

This way we can establish peering with the new ISP using the Public AS as the local AS in the neighbourship config and also reatain the existing peering with old ISP..What we need to make sure is that while sending update to the second ISP we replace the original private AS with the Public AS....

Below commands will be handy for same..

R5(config)#router bgp 64515

R5(config-router)#neighbor x.x.x.x local-as zzzz ?

  no-prepend  Do not prepend local-as to updates from ebgp peers

R5(config-router)#neighbor x.x.x.x local-as zzzz no

R5(config-router)#neighbor x.x.x.x local-as zzzz no-prepend ?

  replace-as  Replace real AS with local AS in the EBGP updates

R5(config-router)#neighbor x.x.x.x local-as zzzz no-prepend

R5(config-router)#neighbor x.x.x.x local-as zzzz no-prepend replace-as

You can refer the below very Useful Cisco Document for same

http://www.cisco.com/en/US/docs/ios/12_3t/12_3t11/feature/guide/gtbgpdas.html

Hope this helps to answer your query.

Regards

Varma

[vpollifrone]

exactly what I was looking for. thanks for your support.