[c-nsp] L3 Switch as a BGP Gateway

[Jay Hennigan]

On 6/27/11 1:30 PM, Murphy, Jay, DOH wrote:
> How about when you stack them as a logical switch. Couldn't one leverage the memory and processing of the stacking?

If you're taking just a default eBGP route from each external neighbor
and using multi-homing as a primary/failover, you can get away with it.
 "Multi-homed BGP gateway" in your original post implies taking at least
a partial table from a diversity of transit providers and/or peers, and
these switches just aren't capable of dealing with anywhere near that
many routes.


> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Jay Hennigan
> Sent: Monday, June 27, 2011 1:11 PM
> To: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] L3 Switch as a BGP Gateway
> 
> On 6/27/11 11:59 AM, Jason Greenberg wrote:
>> Can someone advise me as to why a 3750 L3 Switch (Metro Model) wouldn't outperform a 7300 series router as a multi-homed BGP gateway?  ISRs and Enterprise class routers are still quite a bit more expensive than the L3 Switches, but I'm starting to not understand why.   I understand that L3 switches are less feature rich on the routing end, but suppose that our ASAs are doing most of the complicated filtering.    I know it doesn't sound "right" to have a 3750G used in this manner, but I am having a hard time finding any real reason why not to do it.
> 
> The memory and number of routes are far too small to use these as a
> border router.  Generally adequate for iBGP to inject customer routes
> into your network but way too little for an Internet-facing border.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
Impulse Internet Service  -  http://www.impulse.net/
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