2 MPLS links on same router acting ac Primary/Secondary

[acharyr123]

Hi,

I have some branch routers. I would like to go with BGP with the ISP & wish to have 2 links working in Primary & Secondary setup...Can i achieve this using weight attribute??

[Jon Marshall]

Is it the same ISP that you have 2 connections to ?

One point. There is little point in having 2 ISP connections for redudancy if they terminate on the same router.

Jon

[acharyr123]

Yes.It is the same ISP..

What kind of problem u r referring too??

[Jon Marshall]

Yes you can simply apply a higher weight to the primary ISP connection eg.

router bgp

neiighbor x.x.x.x weight

the higher the weight the more preferred the route.

As to the problem i was referring to, you have redundant ISP connections going to the same router. That router is a single point of failure, it if fails then you have lost both your ISP connections.

Jon

[acharyr123]

Thanks Jon for your clarification..

[Jon Marshall]

Just to add. Weight will only influence the outbound traffic. If you want to influence the route taken by traffic coming to you then you have a number of options -

1) advertise more specific routes out of the primary link and a summarised route out of the secondary link

2) use MED

3) use AS PATH prepending

Jon

[cadet alain]

Hi,

just to add to Jon's last post you could also use community string to influence inbound traffic according to your ISP policy.

Regards.

Alain.

[Marwan ALshawi]

and this is a link for BGP config examples you can follow Jon's recommendations by having inbound and outbound polices to influence in and out path selection jand ust refer to the bellow link for detailed examples and instructions of how to do it

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00800c95bb.shtml

HTH

pls rate the helpful posts

[gerald.suiza]

i would talk to my service provider and ask them what options you have to influence traffic preferring one link over the other on the ISP PE point of view then decide on the method you will use on your CE.