Do all switches have to support QinQ?

[jwbensley]

If I have three switches in a line like below, and port fa0/1 on Sw1 is for vlan 10, which is trunked to fa0/1 on Sw3,

Sw1  --- Sw2 --- Sw3

If I wanted more VLANs between these ports I could set up a QinQ tunnel but switch 2 doesn't support this, does this matter? Do all switches in a QinQ chain have to support QinQ or will they simply read the outter tag and pass the frames blindly?

Many thanks.

[Edison Ortiz · Accepted solution]

For Q-in-Q, only the switches directly connected to the CEs will need it.

The transit switches must have the customer Vlan in their databases and the Vlan(s) must be in forwarding state / not pruned.

[jwbensley]

Thank you for the prompt response