Layer 2 Protocol Tunneling Configuration

Layer 2 protocol tunneling ensures transparent transmission of private Layer 2 PDUs over a public network. To prevent a backbone network edge device from sending the received Layer 2 protocol data units (PDUs) to its CPU for processing and ensure that the Layer 2 PDUs are tunneled across the backbone network, configure the edge device to replace the multicast destination MAC address in Layer 2 PDUs with a specified multicast MAC address.

Overview of Layer 2 Protocol Tunneling: Layer 2 protocol tunneling allows Layer 2 devices to use Layer 2 tunneling technology to transparently transmit Layer 2 protocol data units (PDUs) across a backbone network. Layer 2 protocol tunneling supports standard protocols, such as Spanning Tree Protocol (STP) and Link Aggregation Control Protocol (LACP), as well as user-defined protocols.

Configuration Precautions for Layer 2 Protocol Tunneling

Default Actions on Protocol Packets

Configuring Layer 2 Protocol Tunneling (By Replacing Multicast Destination MAC Address): Some Layer 2 protocols running between user networks, such as Multiple Spanning Tree Protocol (MSTP) and Link Aggregation Control Protocol (LACP), must traverse a backbone network to perform Layer 2 protocol calculation. Therefore, Layer 2 protocol tunneling must be configured.

Layer 2 Protocol Tunneling Configuration (Not By Replacing Multicast Destination MAC Address): L2PDU tunneling allows VPN L2PDUs to be transparently transmitted over a public network. This function is supported only on VPLS or VPWS networks. If L2PDUs traverse the backbone network, they may be processed by edge devices on the backbone network.

Configuration Examples for Layer 2 Protocol Tunneling: This section provides examples for configuring interface-based, VLAN-based, QinQ-based, and hybrid VLAN-based Layer 2 protocol tunneling.