[c-nsp] IEEE 802.1ad vs Cisco's Q-in-Q

[sthaug at nethelp.no]

> At this point we've went through this exercise. We have numerous Extreme
> networks switches. Extreme follows the standard, while Cisco is
> apparently choosing not to. Do a quick search while logged in at
> www.cisco.com for the following: 0x88a8 or 88a8 and you will get exactly
> zero results for either. I find this a bit disturbing when this is in
> fact THE standard for vman/qinq/svlan/whatever xyz vendor chooses to
> call it. Juniper among other companies have also standardized on 0x88a8.
> It would seem to me that if Cisco wants to be a true leader in metro
> Ethernet, they would support the standard that has been around for some
> time now. 

802.1ad came out in 2005. I'm not normally a great Cisco defender - but
popular switches like the 3560 and 3750 series came out earlier than this
and I can't blame Cisco for not supporting 802.1ad on those series of
switches. After the standard came out it would certainly be good to see
new models of switches suuporting it.

Also, I find it hard to see how you can say that Juniper has standardized
on 0x88a8 since the outer Ethertype you get by default is:

- 0x9100 on the E series (ERX)
- 0x8100 on the M series

However, it is correct that the Juniper routers/interfaces which let
you configure double tagging also has the *option* of using 0x88a8 for
the outer Ethertype.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no