Operation Manual – QinQ
H3C S9500 Series Routing Switches
Chapter 1 QinQ Configuration
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Chapter 1 QinQ Configuration
When configuring QinQ, go to these sections for the information you are interested in:
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QinQ Overview
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Configuring VLAN VPN on a Port
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Configuring Traffic Classification-Based Nested VLAN
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Configuring the TPID to Be Used in the Outer Tag
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Configuring VLAN-VPN Tunneling
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Displaying and Maintaining QinQ Configuration
1.1 QinQ Overview
1.1.1 Introduction to QinQ
QinQ is a technique that enables packets to be transmitted across the operators’
backbone networks with VLAN tags of private networks nested in those of public
networks. In public networks, packets of this type are transmitted by their outer VLAN
tags (that is, the VLAN tags of public networks). And those of private networks, which
are nested in the VLAN tags of public networks, remain intact.
Figure 1-1
shows the structure of a single-tagged frame and a double-tagged frame.
Figure 1-1
Single-tagged frame structure vs. double-tagged Ethernet frame structure
Compared with MPLS-based L2VPN, QinQ has the following features:
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Layer 2 VPN tunnels that are simpler.
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QinQ can be implemented without the support of signaling protocols. You can
enable QinQ by static configuring.
As QinQ is implemented through trunk port defined in 802.1Q, all devices along tunnels
with QinQ employed must be 802.1Q-enabled. Therefore, QinQ is suitable for
