198
Step
Command
Remarks
3.
Configure the port link type.
port link-type
{
hybrid
|
trunk
}
By default, the link type of
ports is access.
4.
Configure the port to allow
packets from its PVID and the
transparent VLANs to pass
through.
•
For hybrid ports:
port hybrid
vlan
vlan-id-list
{
tagged
|
untagged
}
•
For trunk ports:
port trunk permit vlan
{
vlan-id-list
|
all
}
By default, trunk ports allow
only packets from VLAN 1 to
pass through. Hybrid ports
allow only packets from
VLAN 1 to pass through
untagged.
5.
Enable QinQ on the port.
qinq enable
By default, QinQ is disabled.
6.
Specify transparent VLANs.
qinq transparent-vlan
vlan-list
By default, transparent
transmission is not configured
for any VLANs on a port.
Configuring the TPID in VLAN tags
TPID identifies a frame as an 802.1Q tagged frame. 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. However, the TPID value
varies with vendors. In a multi-vendor network, you must 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 an untagged frame if its TPID is different from the CVLAN TPID.
A service provider-side port uses the SVLAN TPID to replace the TPID in outgoing frames' SVLAN tags, in
addition to matching incoming tagged frames. SVLAN TPIDs are configurable on a per-port basis.
For example, the PE device is connected to a customer device that uses the TPID 0x8200 and to a
provider device that uses the TPID 0x9100. To be compatible with these devices, you must configure
0x8200 and 0x9100 as the CVLAN TPID and SVLAN TPID, respectively, so the devices can correctly
identify tagged frames.
The TPID in a tagged Ethernet frame 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
.
Table 12
Reserved EtherType values
Protocol type Value
ARP 0x0806
PUP 0x0200
RARP 0x8035
IP 0x0800
IPv6 0x86DD
PPPoE 0x8863/0x8864
MPLS 0x8847/0x8848