26.2.5 Configuring TPID for VLAN Tag

Points to note

The Switch can set the TPID of a VLAN tag to any value. The vlan-dot1q-ethertype command can be used to set the default value for the switch, and the switchport dot1q ethertype command can be used to set the value for each port. Ports for which no value is set are run using the default value for the switch.

The TPID setting for each port is set using the Ethernet interface configuration mode.

Command examples

1. (config)# vlan-dot1q-ethertype 9100

   Sets the default value for the Switch to 0x9100. All ports will run with a VLAN tag TPID of 9100.

2. (config)# interface gigabitethernet 1/0/1

   Switches to the Ethernet interface configuration mode for port 1/0/1.

3. (config-if)# switchport dot1q ethertype 8100

   Sets the TPID of port 1/0/1 to 0x8100. Port 1/0/1 recognizes 0x8100 as the VLAN tag. Other ports run using 0x9100, which is the default value for the switch.

Notes

Because TPIDs use the same position in a frame as an untagged frame EtherType, for 0x8000 and other IPv4 EtherTypes. It might not be possible to configure networks properly when values used as an EtherType are set. Therefore, set values that are not used as EtherType values.