On 09/10/14 13:26, Nathan Ward wrote:
People should really just use 0x88a8 - those who aren’t, can I ask why not? Is it because you’re trying to tunnel it over a switch that doesn’t support 802.1ad or something? I’m not saying it’s wrong, I’m interested in understanding the situations in which you might do this.

There's a bunch of stuff that still doesn't support 802.1ad, even if it does support stacked Q - most Linux distros for starters. If you're looking to do the kind of neat stuff that Linux & friends can do for you at layer 3, then you're pretty much stuck with TPID=8100 and pre-802.1ad semantics.

I can't see why you'd use or expect 802.1ad semantics (including DEI) without using the 802.1ad TPID of 88a8. To me, the whole point of offering an outer TPID of 8100 is for backward compatibility with pre-802.1ad compatible devices.

-- don