# Layer2 Protocol Tunneling

## Navigation

Right-click the device and then select Configure > Layer2 Protocol Tunneling.

From the Layer2 Protocol Tunneling dialog box, you can configure the Class of Service setting for this device. Note that this dialog box is available only on:

> devices running Cisco IOS release 12.2(18)EW or later

> interfaces that support tunneling

Tunneling allows separate local networks, connected through an ISP, to be recognized as one VLAN. This is possible because packets are transported by the ISP from one network to another, giving the impression that the two networks are really one network. Tunneling is supported by the following Layer2 protocols: Cisco Discovery Protocol (CDP), VLAN Trunk Protocol (VTP), and Spanning Tree Protocol (STP).

The following data is displayed:

### Class of Service (cltcTunnelCos)

Specifies the user priority of tunneled PDUs and applies to all incoming tunneled interfaces.