We have been experiencing high input packet drops on interfaces on 6148a's when we are less than ~200mb/s on the 8 ports combined in one case and <100Mb/s in another, not anywhere close to the 8-1 over subscription as advertised. It also got much worse when we went from catos to IOS last week, not sure why. Don't expect too much from a 6148a module.
Matt Buford wrote: >> Can anyone comment on this ? Does this mean we can get a max of 6 Gig >> throughput on a 6148A card and max 2 Gbit on a 6148 ? Or do these >> numbers only apply to etherchannels ? I don't seem to find the right >> performance figures for these cards. > > Issue 1: > > Each group of 8 ports only supports a gigabit. If you get 2 ports in the > same range of 8 both trying to download a gigabit, each one is only going to > receive 500 mbits. If you have a mix of high bandwidth servers and low > bandwidth servers, you should probably spread the high bandwidth servers out > so there is only one big bandwidth user per group of 8 ports. > > Issue 2: > > When using etherchannel, a copy of EVERY PACKET for the entire etherchannel > bundle gets sent to the ASIC. Since the ASIC only has a 1gbit capacity, > this means that the entire etherchannel bundle maxes out at 1gb. But wait! > It isn't just the etherchannel bundle that maxes out at 1gb. It is the > etherchannel bundle plus all other ports on the same ASIC. > > The result: > > So, lets imagine you make an etherchannel with port 3/1 and 4/1. Both cards > are 6148-GE-TX. Your etherchannel downloads at 1gbit. Now, someone else > (not in the Etherchannel) on port 3/2 starts downloading. The downloader > AND the etherchannel now have to share the 1gbit restriction, since the ASIC > handling 3/1-8 has to receive a copy of every etherchannel packet plus every > packet for port 3/2 - all through a 1gbit pipe. > > The moral of the story is don't etherchannel on WS-6148-GE-TX cards (unless > doing so only for redundancy and not for bandwidth). > > _______________________________________________ > 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/
