[lkml]   [2001]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Poor Performance for ethernet bonding
Thomas Davis wrote:
> Ben Greear wrote:
> >
> > Couldn't the bonding code be made to distribute pkts to one interface or
> > another based on a hash of the sending IP port or something? Seems like that
> > would fix the reordering problem for IP packets.... It wouldn't help for
> > a single stream, but I'm guessing the real world problem involves many streams,
> > which on average should hash such that the load is balanced...
> >
> Cisco etherchannel does this, by XOR'ing the dest address with the
> source address, AND'ing with # of interfaces (limiting you to a power of
> 2), and then using the number to determine what channel to use.
> Now, you end up in a 4 way Etherchannel, all the traffic going down one
> channel, and the none going down the other three. Does that sound like
> a balanced solution?

If Cisco can't do a balanced hash, that doesn't mean the idea is bad,
it just means they implemented it poorly. I would think that
something as simple as: src_ip_port % num_devices would give a
fairly even spread. I'm sure you could get fancier and take other
fields (dst_ip_port) into account in your hash.

Ben Greear <> <>
President of Candela Technologies Inc
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 12:58    [W:0.052 / U:0.456 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site