> -----Original Message-----
> From: Simon Horman [mailto:simon.hor...@netronome.com]
> Sent: Wednesday, 10 August, 2016 12:14
> >
> > My suggestion for the action set execution order would therefore be:
> > 3.a push_nsh
> > 3.b         push_eth
> > 3.c push_mpls
> > 4   push_pbb
> > 5   push_vlan
> >
> > I agree that this is somewhat arbitrary and can be debated, but one can
> achieve any wanted order using the Apply Actions instruction.
> 
> I think that sounds reasonable.
> 
> Actually, I think the important thing is to define the ordering clearly.
> I wonder if taking it to the ONF earlier than later would be wise. It will be
> painful if at some point they chose a different ordering to what is present 
> in the
> wild.

That makes sense.
Does anyone have a reach into the ONF to propose this as OF extensions?

> >
> > Conversely, when you compose the pop_nsh action you need to trigger a
> recirculation of the packet after pop_nsh to have the datapath reparse the
> inner packet and subject it to another megaflow lookup. You should do that by
> calling  ctx_trigger_freeze(ctx) after having composed the pop_mpls action.
> >
> > The same goes for the actions push_eth and pop_eth.
> 
> Yes, I believe that is true except for the last statement.
> 
> I think that push/pop_nsh will likely follow a similar pattern to 
> push/pop_mpls
> as both sets of actions may change the ethernet type of a packet.  But I think
> the case of push/pop_eth is a little different. The way this is modelled is 
> that
> those actions affect the presence of an ethernet header (which is in itself a 
> bit
> special) but not the type of the packet.

I agree with you if the push_eth action is executed on a non-ethernet packet. 

But we also should consider the case that push_eth is executed on an ethernet 
frame, effectively creating a raw MAC in MAC encapsulation. I suggested to use 
the ethertype 0x6658 (used e.g. as protocol type for Transparent Ethernet 
Bridging (Ethernet over GRE)) for this.

See also http://openvswitch.org/pipermail/dev/2016-July/075632.html

Similarly for pop_eth.
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