C
ONFIGURING
IEEE 802.1Q T
UNNELING
32-29switchport dot1q-ethertype
This command sets the Tag Protocol Identifier (TPID) value of a tunnel
port. Use the no form to restore the default setting.
Syntax
switchport dot1q-ethertype tpid
no switchport dot1q-ethertype
tpid – Sets the ethertype value for 802.1Q encapsulation. This
identifier is used to select a nonstandard 2-byte ethertype to
identify 802.1Q tagged frames. The standard ethertype value is
0x8100. (Range: 0-ffff hexadecimal)
Default Setting
No dot1q-ethertype is set.
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
•Use the switchport dot1q-ethertype command to set a custom
802.1Q ethertype value on the selected interface. This feature allows
the switch to interoperate with third-party switches that do not use the
standard 0x8100 ethertype to identify 802.1Q-tagged frames. For
example, if 0x1234 is set as the custom 802.1Q ethertype on a tunnel
port, incoming frames containing that ethertype are assigned to the
VLAN contained in the tag following the ethertype field, as they
would be with a standard 802.1Q trunk. Frames arriving on the port
containing any other ethertype are looked upon as untagged frames,
and assigned to the native VLAN of that port. The ethertype and
priority bits of the tunnel port are also used to process the packet.
All members of a VLAN should be set to the same ethertype.