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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Load Balancing Multiple DS3s (outgoing) on a 7500
On Sat, Mar 13, 2004 at 04:19:40PM -0800, Will Yardley wrote: > > On Fri, Mar 12, 2004 at 11:37:25PM -0500, Joe Abley wrote: > > On 12 Mar 2004, at 23:24, joe mcguckin wrote: > > > > > I suspect that each FE goes to a different AS... > > > > In that case, sample/count outbound traffic volumes by > > (prefix/AS/AS_PATH/something), sort the resulting list, and develop an > > import policy based on the top N entries which shares the traffic by > > tweaking some other attribute to avoid the last-resort tie-break. > > The tool "ehnt" is pretty useful for generating a "top" style list of > ASes in order of the amount of traffic you're sending their way. > > By the way, w/r/t to the tiebreaker stuff, note that (on Cisco devices) > if you don't have "bgp bestpath compare-routerid" set, the route that > was received first will be preferred. This minimizes route-flap, but can > cause weird shifts in your traffic patterns when one bgp session or > another goes down (credit goes to Mark Nagel for figuring out this one > for me). > Also, check out: http://www.nanog.org/mtg-0206/feamster.html for some general guidelines, pitfalls, etc. (The paper linked from the presentation recently appeared in ACM Sigcomm CCR.) -Nick
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