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New Member

Load Balancing resulting into Asymmetric Routing

Dear All,

Following is an overview of my network

Remote location (Spoke ) router is having 2 MPLS link terminating from different SPs (SP1 and SP2) and SP1 is being preffered for SAP, SMTP etc traffic. Traffic initation happens mostly from Spoke locations

At my HQ site i have two core routers , with each router having 2nos of MPLS link from SPs (SP1 and SP2). No preference has been configured on HQ routers.

Till date everything works fine here.

What i want now  "at my HQ also, i want SP1 to be preffered for SAP, SMTP etc traffic. "

Q1) how do i confgiure for return traffic

Q2) suppose pefrence for return traffic is  configured , what if my  SP1 link goes down at spoke location, my router at HQ will keep on forwarding to SP1 MPLS cloud

I hope my questions are clear.

Thanks

3 REPLIES
Hall of Fame Super Blue

Re: Load Balancing resulting into Asymmetric Routing

From you description you could use PBR.

However you may be able to do it with BGP if that is what you are running between your CE devices and the PE devices.

Is the traffic you want to direct to ISP1 in it's own subnet and are these server used for anything else ?

Basically BGP will allow you to set a preference for networks or even host addresses but not for specific ports whereas PBR can be used for to specify exactly what ports etc. can be used.

It sounds from your description that PBR would be the better choice but some clarification would help.

How are you preferring at the remote end ? Is it with HSRP ?

Jon

New Member

Load Balancing resulting into Asymmetric Routing

Hi Jon,

At the remote end i am preferring the traffic on ISP1  by using  Weight.attribute.

I would be able to do by BGP on HQ routers  but  as i asked earlier suppose pefrence for return traffic is  configured , what if my  SP1 link goes down at spoke location, my router at HQ will keep on forwarding to SP1 MPLS cloud.

Also , i forgot to mention  that i have around 500 spoke locations.

Thanks

Re: Load Balancing resulting into Asymmetric Routing

Hello.

Not clear what is your task! Do you want to prefer SAP and SMTP traffic over one provider and all the other traffic via another (do load-sharing per application)? This kind of task will require any kind of PBR (or PFR or iWAN).

But, if you are talking about routing to prefer single ISP, then you would better draw a diagram of HQ with all the BGP settings are in place. Having the diagram it will be easy to suggest you the solution.

PS: please provide a diagram.

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