Yes, ECMP is enabled. It's just not behaving the way we initially expected.
On Sun, Oct 3, 2010 at 1:39 AM, Reinhold Fischer <[email protected]> wrote: > Is "ip multicast multipath" enabled? Take care of the usage guidlines > and limitations before enabling it ... > > hth > Reinhold > > On Sun, Oct 3, 2010 at 7:10 AM, John Neiberger <[email protected]> wrote: >> This is entirely multicast. We used the s-g-hash to lock each S,G to a >> link, but we didn't think it through. We really should have started >> out using the next-hop-based hash so that the same S,G can be served >> by any link in the group. With s-g-hash, it always gets locked to the >> same bundle. >> >> However, I just thought of another potential culprit. I'm going to >> have to think it through, though. >> >> On Sat, Oct 2, 2010 at 10:17 PM, Keegan Holley >> <[email protected]> wrote: >>> I've seen similar effects. I'm not sure there's a method to evenly >>> distribute traffic for an indefinite period. I'm also not sure what you're >>> routing, but the problems I've seen are usually caused by the fact that each >>> flow/hash result differs in size and duration. Adding extra variables to >>> the equation always helps, but it's almost impossible to keep an even >>> spread. I suppose your current goal is to simply stop the outages though. >>> >>> >>> On Sat, Oct 2, 2010 at 7:17 PM, John Neiberger <[email protected]> wrote: >>>> >>>> I hate to answer my own question, but I think I figured it out. We're >>>> using s-g-hash basic, which is prone to polarization. I think that's >>>> what we're seeing. Our traffic has become polarized and has developed >>>> an affinity for a subset of links in our "bundles". I'm recommending >>>> that we switch to s-g-hash next-hop-based to see if that resolves the >>>> problem. >>>> >>>> On Sat, Oct 2, 2010 at 2:18 PM, John Neiberger <[email protected]> >>>> wrote: >>>> > We converted several connections last week from Etherchannels to >>>> > routed links with ECMP. We verified that traffic was load-sharing over >>>> > those links after making the change. Now, a week later, we are seeing >>>> > instances where traffic is preferring one or two links out of each >>>> > "bundle". In some cases all the traffic is flowing over a single link >>>> > in a four-link setup. This is overloading those connections and we >>>> > can't figure out why. We are using s-g-hash basic. Should we switch to >>>> > s-g-hash next-hop-based? >>>> > >>>> > This is causing production issues right now, so I've opened up a TAC >>>> > case, but I thought I'd ask here, as well, just in case someone had >>>> > seen this before. >>>> > >>>> > Thanks, >>>> > John >>>> > >>>> _______________________________________________ >>>> cisco-nsp mailing list [email protected] >>>> https://puck.nether.net/mailman/listinfo/cisco-nsp >>>> archive at http://puck.nether.net/pipermail/cisco-nsp/ >>>> >>>> >>> >>> >> >> _______________________________________________ >> cisco-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/cisco-nsp >> archive at http://puck.nether.net/pipermail/cisco-nsp/ >> > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
