John, In general the hash is done based on the source address (called S-Hash) There are enhancements to be able to base the hash on S and G (called S-G-Hash) or also taking the next hop into consideration...
Take a look here: http://www.cisco.com/en/US/docs/ios/12_4t/ip_mcast/configuration/guide/m ctlsplt.html Some platforms still have it on the roadmap, so could be not yet available... Arie -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of John Neiberger Sent: Thursday, October 21, 2010 21:08 To: [email protected] Subject: [c-nsp] How does multicast multipath next-hop-based hashingactually work? We've been having a bear of a time trying to get equitable distributions of traffic over sets of links where the traffic is nearly 100% multicast. We seem to end up with a couple of links that have a lot of S,Gs attached to them and other links that only have a few. Since the traffic rate per stream is about the same, this leads to a lot higher utilization on certain links, and in some cases (like at 5:00 AM this morning) one link getting overdriven to the point of dropping production video traffic. We've read the documentation on CCO about multicast multipath, but it doesn't go into enough detail about how the hash works under the hood. We need to understand this in order to engineer a workable (and understandable) solution for this issue. Do any of you know the details? 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/
