Re: agr modes

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Jul 20, 2013 at 11:21:26PM +0200, Pierre-Philipp Braun wrote:
> Hi there,
> 
> I would like some insights and explanations on the aggregate
> capabilities of the agr(4) device.  As I understand it, -link0
> (dash) mode does LACP and should be compatible with manageable
> network switches.  Does the link0 (no dash, load-balance with some
> warning about frame ordering in the manual) works with LACP too?  Is

probably not

> this mode also supposed to work with network hardware vendors?  In

no

> what cases should one use the one or the other?

load-balance is intended to be used for direct link between 2 hosts
supporting this mode. AFAIK a switch is not capable of doing load-balance.

> Any of those is not
> supposed to work with non manageable switches, right?

in the general case, yes. load-balance could work in some specific
cases with non manageable switches, but you'll get the extra
bandwith only for transmit, not receive.

> 
> I tested the default -link0 (dash) mode between two netbsd nodes,
> and it didn't really work out of the box, I had to manually recreate
> the interface on one of the nodes to establish the link and ping,
> even though the '0x3<COLLECTING,DISTRIBUTING>' came right up.  Also
> once the link seemed to be alright, when I physically disconnected
> *one* of the wires, I lost the connection.  So I wasn't very
> successful with this, could be my mistake though, I should try
> again.  I didn't try to validate the link0 (w/o the dash) the same
> way, but it seemed to me that I also had to reinitialize the agr0
> interface on one of the two nodes to make it work.

what network interface do you use ? I found that in most case
you have to change the hardware address of ethernet interfaces before
creating agr(4). All ethernet interface part of the same agr(4) have
to use the same ethernet address.

> 
> On the other hand, as for the link1 mode, I am happily using it on
> my home network on two netbsd hosts, both connected to a non
> manageable switches, and everybody -- even the nodes with no
> aggregates -- pings.

but then you don't get the extra bandwith.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--