[j-nsp] 802.3ad Question

[alexi]

Thanks a lot Mark and Richard

 very clarifying !

BR
Alexi

On Fri, Jan 15, 2010 at 12:43 AM, Richard A Steenbergen <ras at e-gerbil.net>wrote:

> On Fri, Jan 15, 2010 at 09:18:01AM +0800, Mark Tinka wrote:
> > Not quite - what I did say was:
> >
> >       "We're aggregating 3x Gig-E links between both devices, and
> >        it's working fairly well. Traffic distribution from the
> >                M7i to the 6500 is 1:1:1, while traffic
> >        distribution from the 6500 to the M7i is 1:1:0.7 (but this
> >          direction is governed by other Layer 3 devices
> >          upstream of the 6500)."
>
> The 6500/7600 platform (or at least the current generation of cards)
> have only 8 hash buckets available, so if you use a non power-of-2
> number of links like 3 above, what you're actually getting is 3:3:2. The
> problem gets worse as the number of active links increases, so that if
> you have 8 links at 1:1:1:1:1:1:1:1 and you lose one it becomes
> 1:1:1:1:1:1:2, effectively behaving like you only had 4 links instead of
> 7 (well, at least if you care about delivering half the packets on that
> 7th link at any rate).
>
> I'm not aware of any major router vendor who still sells a product with
> anything even beginning to approach this level of BAD. Juniper, Foundry,
> Extreme, Force 10, etc, all have this pretty much nailed down.
>
> --
> Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
> GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
>