[c-nsp] Difference between Cisco Q-in-Q and IEEE 802.1ad

[Arie Vayner (avayner)]

Martin,

>From a quick check I could see support for both 802.1ad (0x88a8) and other custom S-tags (0x9100) on ASR9K. I can also see references on 7600 with ES+ modules.

Some references:
https://supportforums.cisco.com/docs/DOC-15556
http://www.cisco.com/en/US/docs/routers/asr9000/software/asr9k_r4.2/lxvpn/command/reference/b_lxvpn_cr42asr9k_chapter_01.html#wp1086679105
http://www.cisco.com/en/US/products/ps9853/products_tech_note09186a0080c1d17b.shtml

HTH
Arie


-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of sthaug at nethelp.no
Sent: Wednesday, January 1, 2014 9:24 PM
To: m4rtntns at gmail.com
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Difference between Cisco Q-in-Q and IEEE 802.1ad

> I made a simple setup where Cisco Q-in-Q port("switchport mode
> dot1q-tunnel") was facing a laptop. Laptop was sending out frames with 
> 802.1q tag(VID was 10) and Cisco Q-in-Q port pushed another 802.1q field.
> Final frame can be seen here:
> http://www.cloudshark.org/captures/ae485b68e9ed
> 
> Based on this Cisco Q-in-Q frame, the only difference between IEEE 
> 802.1ad frame and Cisco Q-in-Q frame is that former has 0x88a8 as an 
> TPID value for S-tag? I made a small illustration for this:

Correct, it's 0x88a8 vs 0x8100 for the S-tag.

> In addition, are there Cisco switches out there which use 0x88a8 as a 
> TPID value of S-tag by default?

Don't know of any.

> Last but not least, which devices use 0x9100 as a TPID value for 
> S-tags? According to drawing in Wikipedia IEEE 802.1ad article, some 
> do:

Juniper E-series (ERX) routers use 0x9100 by default.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no _______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/