Question on double tagging

[nambi_gct]

Hi, Can anyone help me understand the difference between QinQ and doubletagging.Any pointer will be helpful.

[swaroop.potdar]

Both would mean the same thing in terms of Metro-E switching.

HTH-Cheers,

Swaroop

[cisco_lad2004]

As Swaroop says, it the same!

I will just add that, Q-In-Q, VLAN stacking, or VLAN double tagging is the same.

In MPLS, double tagging can also refer to an MPLS VPN packets. where one TAG is for Next HP PE and the other is fir the actual VPN.

HTH

Sam

[william.caban]

BTW, you can add S-VLAN to the list since other vendors like Juniper, Telco System and others, call it Stacked-Vlan or S-VLAN. For Cisco, you may find the documentation with QinQ, VLAN stacking and of course "dot1q-tunnel".

-W

[awojciech]

Hi,

QinQ is kind of doubletagging where TPID value in outer vlan tag can be set to 0x8100 0x9100. but standard 802.1ad describes doubletagging with inner C-Vlan (customer vlan) and outer S-Vlan (service vlan). where TPID value in S-VLAN can be set to 0x88a8. As you can see there are subtle differences and in case of specific implementation check support for different types of outer tag in detail

Regards

Adam,