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New Member

Which protocol to use

topology.JPG

Hi Guys, Need some suggestions here..

CE is running ebgp with SP MPLS PE router. I am receiving around 7k prefixes

should I run iBGP between the CE between CE and CoreSW1? or OSPF

3 REPLIES
Hall of Fame Super Blue

Which protocol to use

If you only want to use one of the links as a pure backup is there any chance you could just receive a default route on both CEs from your PE routers ?

Jon

New Member

Re: Which protocol to use

thanks for your reply           

Backup router is not CE, its connected to local ISP and have a tunnel conenction to Data centre

in case CE goes down, the traffic will ride on the GRE tunnel via the backup router.

I was wondering the choice between ibgp and ospf (benefits of both )to run between the CE router and the core switches coresw1 and coresw2

Hall of Fame Super Blue

Re: Which protocol to use

Okay but the point still stands ie. if you are always using the primary why do you need to have 7k routes on any internal devices because what is IBGP/OSPF giving you here other than using resources on the network devices.

If you could get a default route from the MPLS cloud then by far the simplest solution is to -

1) run an IGP between the CE and core switches. Redistribute the default into the IGP.

2) on the core switches configure a floating static default route with an AD higher than the IGP learned route pointing to the backup router.

If the CE fails the core switches automatically install the floating static and use the backup link. And if the CE comes back then the default route is learnt again and the floating static is removed from the IP routing table.

No need for 7k worth of prefixes on your core switches devices, only one default route needed.

I'm not trying to not answer your question it's just that if you could receive a default route on the CE from the MPLS cloud it would make it a lot simpler and use a lot less resources on your devices.

Note for this to work properly the default route would need to be received from the MPLS network not generated by the CE device itself.

So is there a possibility of this ?

Edit - you would still need all the routes on the CE if this is MPLS any to any connectivity but only a default route would need to passed back to the core switches.

Jon

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