Subject: Re: connection bonding?
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Dheeraj S <dheeraj@ece.gatech.edu>
List: tech-net
Date: 12/08/2005 12:46:21
On Wed, Dec 07, 2005 at 05:29:41PM -0500, der Mouse wrote:

> >> through to LACP-based load-balancing like agr(4),
> > Please, does LACP (with agr or not) do also redundancy, or only
> > increase throughput?
> 
> Honestly, I have no idea what LACP is for.  Presumably the standard
> would say, but the IEEE demands payment to be allowed to look at their
> standards (which actually makes me question whether we should want to
> follow them, but that's an issue for a different day).
> 
> > That is, if two links are aggregated, and one fails, do all the
> > frames go through the other, or is one half of them lost?
> 
> Everything I've seen indicates that the remaining link(s) pick(s) up
> the load.  Whether this depends on LACP or not I couldn't say.
> 
> One of the most bothersome things about agr(4), to me, is that which
> link a packet goes out seems to depend on nothing but a hash of
> assorted data related to the packet.  This means that if links of
> different speeds are aggregated, the slower one(s) will get overloaded.
> I'd expect it to simply pick the interface with the shortest output
> queue....
> 
The spec explicitly says that it does not support "Operation across multiple
data rates". (pp. 283)

dheeraj