Re: How usable is agr(4)?

[Thor Lancelot Simon <tls%rek.tjls.com@localhost>]

On Tue, Jun 09, 2009 at 03:16:38PM +0200, Manuel Bouyer wrote:
> On Tue, Jun 09, 2009 at 01:43:00PM +0200, Hauke Fath wrote:
> > All,
> >
> > while upgrading a busy nfs fileserver, I have changed it to aggregate  
> > two wm(4) GBit interfaces with agr(4); on the other end is a HP procurve 
> > 2848 switch.
> 
> The balance is done based on a hash of the source and destination
> MAC addresses. So if your traffic is going though a router, you won't have
> load-balancing. If the clients are local (and there's enough of them)
> I would expect it to work.

MAC *and* IP addresses.  But the IP address portion of the hash is weird
and I am not sure it works well in the general case.

What version of NetBSD is this?  I have never seen agr successfully
advance LACP to the forwarding (COLLECTING/DISTRIBUTING) state with any
commercial switch under NetBSD 5 or newer.  But we recently added static
aggregation configuration which should probably work with switches that
are set to do Cisco "etherchannel".

The hash should really use the TCP/UDP port numbers if available but that
means an ugly and potentially costly peek inside the packet.

Thor