3725 for DS3 and BGP

[dokeyad]

I am looking at using a pair of 3725s in a multi provider BGP scenario. I have been able to find very little about the real world experience with these routers. Initially the circuits will be capped at 9Mb and I will be pulling full routes.

Does the 3725 have the horse power to handle a full DS3 at wire speed? How about up to about 15Mb? Also, does BGP require a separate software license with cisco?

Thank you,

Aaron Dokey

[donewald]

Aaron,

You should have no problems running with the 3725's with the information and datarates you've given. If you plan to take full routes from each provider then it would be best to ensure you max out the DRAM (256) on each of these routers. If you are not planning to be a transit between your providers there are other, more efficient ways, to peer with two providers without taking full routes from each of them. Having all these routes will only increase lookup times for next-hop unless you need them. I also believe that BGP comes with the SW license you purchase and does not require separate licensing (although I could be wrong there).

Hope this helps you,

Don

[dokeyad]

Don,

Thank you for the response. Is there anywhere you might point me on the more effecient means of multihoming with two providers? We are hoping to load balance incoming and outgoing between the two providers as much as possible.

Thanks again,

Aaron Dokey

[donewald]

Aaron,

There are many ways to accomplish this with BGP. Here is a URL that has some information that might help you.

http://www.cisco.com/en/US/partner/tech/tk648/tk365/technologies_configuration_example09186a00800945bf.shtml

The key is to take a minimalist approach to routes. If you don't need them, filter them or ask your provider to. Using defaults from your providers for outbound traffic might get you what you need but you might find you need a specific set of routes to ensure you exit through the correct provider link so as not to take a sub-optmial path. Depending a lot on where return traffic is coming from and what is the shortest AS Path to your AS will determine return path. As Path prepend and alter this behavior though. You'll really need to run your routers for a time and tweak on them to get the desired results based on traffic flow.

Hope this helps you,

Don