Vlan-Vpn Tpid - 3Com Switch 4500 Family Manual

<Sysname> system-view
System View: return to User View with Ctrl+Z.
[Sysname] interface Ethernet 1/0/1
[Sysname-Ethernet1/0/1] vlan-vpn priority 3 remark 5

vlan-vpn tpid

Syntax
vlan-vpn tpid value
undo vlan-vpn tpid
View
Ethernet port view
Parameters
value: User-defined TPID value (in hexadecimal format), in the range 0x0001 to 0xFFFF.
Description
Use the vlan-vpn tpid command to set the TPID value for a port. With the TPID value set on a port, the
port fills the value to the TPID field of the outer tag to be added for a packet and, upon receiving a packet,
compares the TPID value with the TPID field of the packet to determine whether the packet carries a
VLAN tag or not.
Use the undo vlan-vpn tpid command to restore the default TPID value.
The default TPID value is 0x8100.
For the position and function of the TPID field in a packet, refer to VLAN Operation.
The TPID field in an Ethernet frame has the same position with the protocol type field in a frame without
a VLAN tag. To prevent other devices in the network from recognizing the tag-encapsulated packets of
the current switch as protocol packets, you are not allowed to set the TPID value to any of the values in
the table below.
Table 1-3 Common Ethernet frame protocol type values
ARP
IP
MPLS
IPX
IS-IS
LACP
802.1x
Protocol type
0x0806
0x0800
0x8847/0x8848
0x8137
0x8000
0x8809
0x888E
1-5
Value