Well bgp is not exactly a routing protocol per se to load balance or route 
packets.

BGP is more of like a route publisher.

You use BGP to GET the routes..
You use IGP (ospf, eigrp, etc) to ROUTE the routes..

Yes you can use bgp to achieve symmetric flow distribution of traffic along
your two providers, if you are up for the eliteness ;-)

-hc

-- 
Sincerely,
  Haesu C.
  TowardEX Technologies, Inc.
  WWW: http://www.towardex.com
  E-mail: haesu@...
  Cell: (978) 394-2867

on Tue, Jul 15, 2003 at 03:30:17PM -0700, Christopher J. Wolff wrote:
> Mike,
> 
> You are correct, load balancing bgp is wacky.  Why can't BGP be more
> like EIGRP or OSPF? :)
> 
> Christopher J. Wolff, VP CIO
> Broadband Laboratories, Inc.
> http://www.bblabs.com 
> 
> -----Original Message-----
> From: Michael Weinstock [mailto:MWeinstock@...> Sent: Tuesday, July 15, 2003 3:20 PM
> To: isp-bgp@isp-bgp.com
> Subject: [isp-bgp] RE: Sample BGP Config
> 
> Howdie,
> 
> >From what you are saying you are describing the default behaviour of
> BGP.  Your two BGP routers will "know" what the shortest AS path is to a
> certain AS through their iBGP session.
> 
> i.e. if router A has a shorter path through provider A to an AS then
> router B will know that and forward traffic for that AS through router
> A.
> 
> Load balancing and BGP is the route to madness... :) ... unless you have
> a reason to ( like you circuits getting maxed to one of the providers )
> my advice is not to seek to influence the traffic for the sake of it.  
> 
> I recommend Sam Halabi's Internet Routing Architecture's from Cisco
> Press for a read on the how/why/where of BGP.
> 
> regards,
> mike
> 
>  
> 
> -----Original Message-----
> From: Christopher J. Wolff [mailto:chris@...> Sent: Wednesday, 16 July 2003 9:59 a.m.
> To: isp-bgp@isp-bgp.com
> Subject: [isp-bgp] RE: Sample BGP Config
> 
> 
> Michael,
> 
> Thanks for the response.  The example I read was "Load Sharing when
> Multihomed to Two ISPs via Multiple Local Routers"
> 
> The outbound traffic policy in this example limits traffic to one of the
> two providers unless there is a failure.
> 
> The outbound traffic policy is as follows: 
> Traffic destined to AS 300 goes via the R1 - ISP(A) link. 
> Traffic destined to AS 400 goes via the R2 - ISP(B) link. 
> All other traffic should prefer default route 0.0.0.0 via the R1 -
> ISP(A) link. 
> If the R1 - ISP(A) link fails, all traffic should go via the R2 - ISP(B)
> link. 
> 
> I'd like to have outbound traffic take the shortest path if both ISP's
> are up and fail over to the other ISP if one ISP link fails.
> 
> 
> Christopher J. Wolff, VP CIO
> Broadband Laboratories, Inc.
> http://www.bblabs.com 
> 
> -----Original Message-----
> From: Michael Weinstock [mailto:MWeinstock@...> Sent: Tuesday, July 15, 2003 2:50 PM
> To: isp-bgp@isp-bgp.com
> Subject: [isp-bgp] RE: Sample BGP Config
> 
> Hello,
> 
> You didnt like it? Perhaps specify what you didnt like... As the answer
> will be based on Cisco's docs.
> 
> -----Original Message-----
> From: Christopher J. Wolff [mailto:chris@...> Sent: Wednesday, 16 July 2003 9:47 a.m.
> To: isp-bgp@isp-bgp.com
> Subject: [isp-bgp] Sample BGP Config
> 
> 
> Hello,
> 
> I'm looking for a couple of sample cisco configs that illustrate two
> multihomed routers connected by an IGP session.  For example;
> 
> Router 1----------Isp 1
> |
> |
> IGP
> |
> |
> Router 2----------Isp 2
> 
> I read the Cisco scenarios for multihomed networks documents but I
> didn't like what I read.  Thank you in advance.
> 
> C.J. Wolff, VP CIO
> Broadband Laboratories, Inc.
> http://www.bblabs.com 
> 
> 
> 
> 
> _______________ 

>  ______________



> 
> 
> _______________ 

>  ______________



> 
> 
> 
> _______________ 

>  ______________



> 
> 
> _______________ 

>  ______________



> 
> 
> 

Replies

[isp-bgp] RE: Sample BGP Config, Ken-ichi Kobayashi

Replies

[isp-bgp] RE: Sample BGP Config, Michael Weinstock

[isp-bgp] RE: Sample BGP Config, Christopher J. Wolff