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New Member

Preferred BGP Route into Network over Backup Link

We have a pretty simple layout with two ISPs. Our preferred path into the network is through one carrier, but the traffic comes into through the carrier we would prefer as a backup. I've prepended the ASN multiple times, but this hasn't fixed the problem. Any suggestions?

TIA

3 REPLIES
New Member

Re: Preferred BGP Route into Network over Backup Link

Hi,

Can you share how have you advertised your prefixes and how have you applied PBR to control the downstream traffic?

please share.

New Member

Re: Preferred BGP Route into Network over Backup Link

The problem is better identified. A local ISP said he is seeing the ASN prepended from Levl3 (one peering partner), but he isn't getting a route from AT&T who they also peer with. We are in the process of contacting AT&T.

Thanks for your time.

New Member

Re: Preferred BGP Route into Network over Backup Link

Hi,

I have a very strong feeling that ISP1 and ISP2 have a peering agreement.

A thought to it would be.

As the ISP2 to lower the local preference within his AS for your network range to either the default so that AS prepend helps or less than the local preference he has set for ISP1.

-Sai.

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