RE: Using BGP to multihome on links of different bandwidth
Henning Brauer wrote: > * Alex Thurlow <[EMAIL PROTECTED]> [2006-07-26 06:11]: .. >> Under just a normal BGP setup, our 100Mb line would be saturated as >> it attempted to send traffic there based on routing distance. >> Because of this, there are IPtables rules that count how many pps >> are going on the 100Mb line, and if there are over a certain amount, >> they mangle the packets and send them over the OC-12 instead. In >> this way, we are able to share these 2 lines of differing bandwidth. > > I would just play with local-preference based on source AS > for a few big > ASes to move them to the OC-12 line and do that until the usage is > somewhat balanced. Some ISPs also accept custom (no-export) communities to help adjust the inbound traffic. These communities can be used to not export your advertised space to one (or many) of the ISP's upstreams, this will cause the upstream to prefer your other link when sending traffic to you. -Steve S.
Re: Using BGP to multihome on links of different bandwidth
* Alex Thurlow <[EMAIL PROTECTED]> [2006-07-26 06:11]: > New to the list, and with a question I can't seem to find an answer to > anywhere else. A little preface - I have recently switched jobs, so I > am in a new network situation. There are some upcoming changes, and I > wish to switch from our current Linux router to OpenBSD-pf. > > We currently have 2 links that are shared via BGP. One is an OC-12, and > the other is 100Mb ethernet. The reason we have lines of unmatched > speed is that we could get the 100Mb cheap and are wanting to test the > usefulness of multihoming. > > Under just a normal BGP setup, our 100Mb line would be saturated as it > attempted to send traffic there based on routing distance. Because of > this, there are IPtables rules that count how many pps are going on the > 100Mb line, and if there are over a certain amount, they mangle the > packets and send them over the OC-12 instead. In this way, we are able > to share these 2 lines of differing bandwidth. I would just play with local-preference based on source AS for a few big ASes to move them to the OC-12 line and do that until the usage is somewhat balanced. -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de OpenBSD-based Webhosting, Mail Services, Managed Servers, ...
Re: Using BGP to multihome on links of different bandwidth
On 07/25/2006 08:46:49 PM, Alex Thurlow wrote: We currently have 2 links that are shared via BGP. One is an OC-12, and the other is 100Mb ethernet. Under just a normal BGP setup, our 100Mb line would be saturated as it attempted to send traffic there based on routing distance. My question is, is there a way to share these 2 lines and not saturate the smaller one? There's probably a way to use the "probability" parameter in conjunction with "route-to", especially if you're doing policy based routing. However, that's off the top of my head. I've not tried any such thing and am a BGP noob so can't say what the interactions are there. Seems to me you might need to abandon BGP. If so, one way to go is to partition the internet with 2 static routes, and poke at it with a stick until you get the bandwidth balance right. Also, it's not clear to me how you're going to keep the inbound traffic from saturating the link, unless you're nat-ting or something and do the "probability" with that. Regards, Karl <[EMAIL PROTECTED]> Free Software: "You don't pay back, you pay forward." -- Robert A. Heinlein
