BGP with two ISP

[engineer_msu]

Dear All,

I am trying to achieve below scenario, need your expert suggestions and help.

I have two Sites A and B

Site-A (Head Office, Datacenter)

Subnets at Site A = A.A.A.0/24, B.B.B.0/24, C.C.C.0/24, D.D.D.0/24

Site-B (Remote Office)

Subnets at Site B = X.X.X.0/24 AND Y.Y.Y.0/24

We have two MPLS L3 links from two different service providers.

I want to use both of the links as active - active with symmetric routing. from HO i can use weight or LP to to send the traffic to different subnets.

But from Remote Office, I need to send traffic to all the subnets of HO from ISP-1 for X.X.X.0/24 and ISP-2 from Y.Y.Y.0/24

I tried to achieve this with route map with extended access list setting up LP or Weight but not working. traffic is sent over one link only accessed from both subnets.

[Jon Marshall · Accepted solution]

You can't do this with BGP.

The issue is you are trying to route based on source IP address from the remote office and there is no way to do this with a routing protocol because they route based on destination IP address.

You will need to use PBR on the remote office router if you want to achieve this.

Jon

[engineer_msu]

Thanks for clarifying my doubt about routing based on source subnet.

You are 100% correct.

I will use PBR with IPSLA Tracking as this is the only option.

[jatinder sharma]

Hello,

yes you can achieve this using policy based routing on remote router..