Operation Manual – QinQ-BPDU Tunneling
H3C S3610&S5510 Series Ethernet Switches
Chapter 1 QinQ Configuration
1-2
Advantages of QinQ:
z
Addresses the shortage of public VLAN ID resource.
z
Enables customers to plan their own VLAN IDs, without running into conflicts with
public network VLAN IDs.
z
Provides an easy-to-do Layer 2 VPN solution for small-sized MANs or intranets.
Note:
The QinQ feature requires configurations only on the service provider network, and not
on the customer network.
1.1.2 Implementations of QinQ
There are two types of QinQ implementations: basic QinQ and selective QinQ.
1) Basic
QinQ
Basic QinQ is a port-based feature, which is implemented through VLAN VPN.
With the VLAN VPN feature enabled on a port, when a frame arrives at the port, the
switch will tag it with the port’s default VLAN tag, regardless of whether the frame is
tagged or untagged. If the received frame is already tagged, this frame becomes a
double-tagged frame; if it is an untagged frame, it is tagged with the port’s default VLAN
tag.
2) Selective
QinQ
Selective QinQ is a more flexible, VLAN-based implementation of QinQ. In addition to
all the functions of basic QinQ, selective QinQ can tag the frame with different outer
VLAN tags based on different inner VLAN IDs.
1.1.3 Modification of TPID Value of QinQ Frames
A VLAN tag uses the tag protocol identifier (TPID) field to identify the protocol type of
the tag. The value of this field, as defined in IEEE 802.1Q, is 0x8100.
shows the 802.1Q-defined tag structure of an Ethernet frame.
Figure 1-2
VLAN Tag structure of an Ethernet frame
