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Trying to influence BGP routes with 2 different ISPs

Hi Everyone,

I'm trying to figure out the best way to do this.  Basically, I have a router that's peering with 2 different providers using BGP.  I want to make sure that certain network follow a specific provider as a primary, but can also use the second provider as a backup.

(see image attached)

I am provided a /23 address that I will be advertising to the BGP neighbors.  I would like a /24 intended for PC-A go down ISP-A as primary, and ISP-B as secondary; but also at the same time have a /24 intended for PC-B go down ISP-B as primary and ISP-A as secondary.

I'm considering using route-maps

Is this something that I would want to use?

ip access-list standard PC_A

permit 1.1.0.0 0.0.0.255

ip access-list standard PC_B

permit 1.1.1.0 0.0.0.255

route-map RMAP_A_IN permit 10

    match ip address PC-A

        set local-preference 200

route-map RMAP_A_IN permit 20

    match ip address PC_A

        set local-preference 100

route-map RMAP_A_IN permit 30

        set local-preference 50

route-map RMAP_B_IN permit 10

     match ip address PC_B

        set local-preference 200

route-map RMAP_B_IN permit 20

    match ip address PC_B

        set local-preference 100

route-map RMAP_B_IN permit 30

        set local-preference 50

router bgp 12345

    network 1.1.0.0

    network 1.1.1.0

    neighbor ISP-A remote-as 5555

    neighbor ISP-A route-map RMAP_A_IN in

    neighbor ISP-B remote-as 7777

    neighbor ISB-B route-map RMAP_B_IN in

Everyone's tags (3)
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Re: Trying to influence BGP routes with 2 different ISPs

Hi,

Seems like you have a single router with two ISPs and also you are talking about BGP configuration for inbound traffic Only.

How about outbound traffic?

In terms of inbound traffic control (mainly ISPs), I recommended use their BGP community strings.

It is not only efficient nor effective. Your BGP attribute might not be working within ISP's network.

Also, your configuration would be a lot simpler. Check below link for easy to understand

http://showipbgp.com/bgp-configurations/cisco.html

I hope it is informative for you

C