Already running "bgp bestpath as-path multipath-relax" ---- ---- ---- ---- Chris Gotstein, Sr Network Engineer, UP Logon/Computer Connection UP http://uplogon.com | +1 906 774 4847 | [email protected]
On 4/15/2010 12:22 PM, Anton Kapela wrote: > > looking at: > >> It's inbound i'm mostly concerned with. I'm taking full routes from >> both providers. Paths to both a relatively equal, so the path with the >> lowest ID is winning, causing it to be overloaded. > > and: > >> I've looked into the communities option, but only Qwest supports them, my >> other provider doesn't support communities at this time. Though the Qwest >> link is the one i want to push more traffic to, so maybe i can just use >> their communities and see what happens. > > give me the impression you're concerned with 'attracting' even loads of > bits/sec inbound, and outbound on your links. Depending on the 'qualitative > difference' between the two networks (i.e. is your 2nd upstream simply > between you and $transit_free_networks? or are they a reseller of a reseller > of a tier1?), you may be able to get away with 'more' ECMP behavior for a > larger number of prefixes: "bgp bestpath as-path multipath-relax" > > this means that even with different as's in the path, your router will > generate ECMP routes for any BGP route with the same number of AS's in the > path. So, if qwest shows you an average as path length of 3.x to 90% of the > table, and $other isp shows you an average of 4.x, prepend inbound from quest > (make their paths look longer), and then gain the ECMP-ness that comes from > mostly-same AS-paths. > > as others noted, l3/l4 hashing will make some aspects of troubleshooting > "slightly annoying" -- and this command will also cause your router to chew a > small bit more dram for the CEF table due to new NH's for many thousands of > routes that previously had none. > > probably best to toss this on and clear ip bgp * soft sometime after most of > your users are fast asleep. > > -Tk _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
