QinQ Configuration example

This configuration example uses four switches to establish a QinQ tunnel through the provider network.

The design parameters are as follows:

The provider edge bridge and the provider core bridge are configured in svlan mode.
Each customer is associated with a single S-VLAN connecting two separate sites: customer A's VLANs (C-VLANs 1-10) are associated with S-VLAN 100; and customer B's VLANs (C-VLANs 1-20) are associated with S-VLAN 200.

NOTE:

The VLANs of customers A and B can overlap: this will not result in intermixing of customer frames in the provider cloud because the S-VLANs associated with each customer are different.
Core devices are not mandatory to establish a QinQ tunnel. For example, two edge-bridges can be connected directly to create a provider bridge network.
The relationship between S-VLANs and C-VIDs is typically one to many. An alternative configuration might associate a single customer's C-VIDs with more than one S-VLAN. Such a configuration would most likely be used to tunnel distinct C-VIDs through various S-VLANs, but seldom be used to send the same C-VID through multiple S-VLANs.

At the end of the configuration, the following settings will apply:

All customer A site traffic received on port A1 will be associated with S-VLAN 100. This is independent of the C-VLAN tag information that the customer frames may carry.
All customer B Site 1 traffic will be associated with S-VLAN 200 and be switched out to the core (uplinks A3, A4) with the S-VLAN tag-id of 200.
The frame size will increase by 4 since ports A3 and A4 are tagged members of S-VLAN 100 and 200.

To configure the switch, follow these steps:

Procedure

Enable QinQ:
```
Edgel(config)# qinq svlan tag-type 88a8
```
Reboot the box with the configuration saved to transfer into svlan bridge mode.
NOTE:
A reboot is required for the QinQ enable command to take effect.
Configure S-VLANs and ports connected to the customer network.
```
Edge1(config)# svlan 100
Edge1(svlan-100)# untagged A1
Edge1(svlan-100)# exit
Edge1(config)# int A1 qinq port-type customer-network
Edge1(config)# svlan 200
Edge1(svlan-200)# untagged A2
Edge1(svlan-200)# exit
Edge1(config)# int A2 qinq port-type customer-network
```
NOTE:
Customer A is assigned S-VLAN 100 and customer B is assigned S-VLAN 200. However, the same customer can be associated with more than one SVLAN. Also, interfaces A1 and A2 are configured as customer network ports because they are linked to customer bridges.
Configure the provider ports leading to the core of the provider network.
```
Edge1(config)# svlan 100 tagged A3, A4
Edge1(config)# svlan 200 tagged A3, A4
Edge1(config)# interface A3,A4 qinq port-type provider-network
```
NOTE:
As recommended by IEEE 802.1ad specification, uplink ports should generally be configured as tagged ports for S-VLANs that are used to carry customer traffic. However, this is not a mandatory requirement on switches—S-VLANs that are used for internal provider network use (not carrying customer traffic but for management of the provider network devices) can have untagged port memberships.