QinQ Default Tuneling STAG Ethertype WS-C3560CX & C9300

[rjde]

Hi community,

when configuring QinQ Tunneling on WS-C3560CX IOS 15.2(7)  & C9300-48P-A IOS 17.6.5, please what is the default STAG ethertype: 0x8100 or 0x88A8 that the devices will use? 

if the STAG QinQ Tuneling ethertype standard is 0x8100, please how can I change that to 0x88A8? The command "vlan dot1q ethertype 0x88A8" does not exist on both. 

Since now, tks!

[Giuseppe Larosa]

Hello @rjde ,

according to recent IOS XE config guide the cat 9300 should follow the IEEE standard

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/17-13/configuration_guide/lyr2/b_1713_lyr2_9300_cg/configuring_ieee_802_1q_tunneling.html

so it should use the special ethertype 0x88A8 for the external metro tag or service provider tag.

The older Catalyst 3560 may use a different value and this can cause interoperability issues.

But it is likely using the standard value

I have checked some other vendor forums

https://community.juniper.net/discussion/q-in-q-0x8100-or-0x9100

if the 0x88A8 was already used in 2011 I guess also the Catalyar 3560 should be using it.

Hope to help

Giuseppe

[rjde]

Hi @Giuseppe Larosa tks for the contribution and on 9300 Config. Guide I don`t see that info there, I am looking for a clear statement regarding ethertype on both devices as default settings and if/how is possible to change that.

From my tests, it is not possible to change and no clear statement (Cisco documentation) regarding that. 

I am planing to raise a TAC Ticket and try to get it from them. Please if you have found something as clear statement from Cisco documentation, I will be happy to have!

Once again, tks!