BGP

[bellah123]

We have 2 Internet Edge routers, each with an Internet circuit to the same ISP. We wants the ISP to prefer R1 over R2 for all traffic destined to our public network x.x.0.0/16 and also wants the path through R2 to remain available if R1 fails. We are currently advertising x.x.0.0/16 over both links via eBGP. We are not allowed to use any BGP attributes (prepending, MED, etc…) to get the job done. Without using any attribute native to BGP, how would you make your ISP prefer R1 over R2 for reaching the x.x.0.0/16 hosts in your enterprise?

[Georg Pauwen]

Hello,

without using any BGP attributes to influence path preference, you could use IP SLA in conjunction with an EEM script for failover, which basically means only one router/path is available, and when that one fails, the other one takes over.

Is this a lab scenario, or a live network ? Post the full configs of both routers so we can fill in the details...

[paul driver · Accepted solution]

Hello

 Without using any attribute native to BGP, how would you make your ISP prefer R1 over R2 for reaching the x.x.0.0/16 hosts in your enterprise?

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The easiest way would to advertise a more specific network prefix from that /16 over the link you wish your isp to take peer

Res

paul