Implementation Of Vlan-Vpn; Inner-To-Outer Tag Priority Replicating And Mapping - H3C S5600 Series Operation Manual

Operation Manual – VLAN-VPN
H3C S5600 Series Ethernet Switches
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Figure 1-2 Structure of packets with double-layer VLAN tags
Compared with MPLS-based Layer 2 VPN, VLAN-VPN has the following features:
It provides Layer 2 VPN tunnels that are simpler.
VLAN-VPN can be implemented through manual configuration. That is, signaling
protocol-related configuration is not needed.
The VLAN-VPN feature provides you with the following benefits:
Saves public network VLAN ID resource.
You can have VLAN IDs of your own, which is independent of public network
VLAN IDs.
Provides simple Layer 2 VPN solutions for small-sized MANs or intranets.

1.1.2 Implementation of VLAN-VPN

With the VLAN-VPN feature enabled, no matter whether or not a received packet
already carries a VLAN tag, the switch will tag the received packet with the default
VLAN tag of the receiving port and add the source MAC address to the MAC address
table of the default VLAN. When a packet reaches a VLAN-VPN-enabled port:
If the packet already carries a VLAN tag, the packet becomes a dual-tagged
packet.
Otherwise, the packet becomes a packet carrying the default VLAN tag of the port.

1.1.3 Inner-to-Outer Tag Priority Replicating and Mapping

As shown in
of this 3-bit field is in the range 0 to 7. By configuring inner-to-outer tag priority
replicating or mapping for a VLAN-VPN-enabled port, you can replicate the inner tag
priority to the outer tag or assign outer tags of different priorities to packets according to
their inner tag priorities.
Figure 1-3 The structure of the VLAN tag in an Ethernet frame
Destination MAC address
Source MAC address
Figure 1-3, the user priority field is the 802.1p priority of the tag. The value
Chapter 1 VLAN-VPN Configuration
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Outer VLAN Tag
Inner VLAN Tag
Data
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