Best BGP strategy for 2 routers with 2 different ISP links each

cisconoobie · ‎12-24-2007

I have 2 routers each with 2 different ISPs for a total of 4 ISPs. Each ISP provides 100Mbps.

What would be the best BGP config strategy to utilize each ISP in the most efficient manner?

Right now I have defaults setup and BGP out of the box config chooses the preferred routes.

This is a datacenter, not a transit! and I need to make sure we have the best connectivity from users around the world connecting to our webservers.

Please advise.

royalblues · ‎12-24-2007

Are you receiving the Full interent BGP table from all the ISPs and What is the interior protocol running that choses the exit router?

Narayan

Danilo Dy · ‎12-24-2007

Hi,

Nice, you have a distributed connection to 4 ISP's.

Utilizing them effeciently is one thing, the important thing is which one of them is the best path to a remote network domain.

BGP uses algorithms to choose the best path automatically. But BGP best path is not always the BEST PATH. For example, BGP best path algorithm doesn't include latency and congestion.

Take one remote AS for example and try ping the IP address in that AS. Try to route that IP address statically to three other ISP and see the difference. If the BGP best path is not the BEST PATH for you in terms of latency and congestion, you can select the ISP which you think is the BEST PATH for you and create a route map with higher local-preference to the ISP of your choice. This will ensure all outgoing traffic to that AS will pass thru the ISP of your choice.

Regards,

Dandy