Configuring the TPID in VLAN tags

TPID identifies a frame as an 802.1Q tagged frame. The TPID value varies by vendor. On the device, the TPID in the 802.1Q tag added on a QinQ-enabled port is 0x8100 by default, in compliance with IEEE 802.1Q. In a multi-vendor network, make sure the TPID setting is the same across all devices so 802.1Q tagged frames can be identified correctly.

TPID settings include CVLAN TPID and SVLAN TPID.

A QinQ-enabled port uses the CLAN TPID to match incoming tagged frames. An incoming frame is handled as untagged if its TPID is different from the CVLAN TPID.

SVLAN TPIDs are configurable on a per-port basis. A service provider-side port uses the SVLAN TPID to replace the TPID in outgoing frames' SVLAN tags and match incoming tagged frames. An incoming frame is handled as untagged if the TPID in its outer VLAN tag is different from the SVLAN TPID.

For example, a PE device is connected to a customer device that uses the TPID 0x8200 and to a provider device that uses the TPID 0x9100. For correct packet processing, you must set the CVLAN TPID and SVLAN TPID to 0x8200 and 0x9100 on the PE, respectively.

The TPID field is in the same position as the EtherType field in an untagged Ethernet frame. To ensure correct packet type identification, do not set the TPID value to any of the values listed in Table 16.