On Mon, 2006-31-07 at 08:30 -0400, John W. Linville wrote:

On Mon, Jul 31, 2006 at 10:15:40AM +0200, Christophe Devriese wrote:

quoted

If you bond 2 vlan subinterfaces, the patch is not necessary at all. In that 
case also the source device will be changed from eth0.<vlan> to bond<x>. So 
that's correct behavior no ?

In the second case, you create vlan subifs on a bonding device, vlan 
subinterfaces will be created on the slave interfaces. In that case the vlan 

(This is not directed at Christophe, or anyone in particular...)

<rant>

Am I the only one that thinks that our handling of LAN L2 stuff
is at best a little "too" flexible (and at worst a collection of
nasty hacks)?

I mean, do we really need both the ability to bond multiple vlan
interfaces AND the ability to have vlan interfaces on top of a bond?
How many people really appreciate the subtle(?) differences?

Then throw bridging into the mix!  If I'm using VLANs and bonds in
a bridged environment, do I bridge the bonds, or bond the bridges?
Do the VLANs come before the bonds?  after the bridges?  or somewhere
in-between?  Do all these combinations even work together?  Who has
the definitive answer (besides the code itself)?

I have no doubt that there are plenty of opportunities for cleverness
here (and no doubt dragons too).  I just doubt that most of them
are worth the complexities introduced by our current collection of
"transparently" stackable pseudo-drivers and strategically placed hacks
(e.g. skb_bond).  All that, and it still isn't clear to me how we
can cleanly accomodate 802.1s (which adds VLAN awareness to bridging).

Do we hold the view that our L2 code is on par with the rest of
our code?  Is there an appetite for a clean-up?  Or is it just me?

</rant>

If you made it this far, thanks for listening...I feel better now. :-)

Yes, I made it this far and you do make good arguement (or i may be
over-dosed ;->).
I have seen the following setups that are useful:

1) Vlans with bridges; in which one or more vlans exist per ethernet
port. Broadcast packets within such vlans are restricted to just those
vlans by the bridge.
2) complicate the above a little by having multiple spanning trees. 
3) Add to the above link layer HA (802.1ad or otherwise as presented
today by Bonding).

To answer your question; i think yes we need all 3.
Unfortunately the 3 above are all done by different people with
different intentions altogether. I think BGrears end goal was VLANs for
an end host. I think Lennert wrote the original Bridge code and for a
while had some VLAN code that worked well with bridging (that code died
as far as i know). Then bonding - theres some pre-historic relation to
it since D Becker days and then the good folks from Intel adding about
1M features to it. Yes, the fact all 3 need to work together is a
mess ;-> (but there are good pragmatic reasons for them to work
together)...
Hope that helps ;->

cheers,
jamal