3Com 4500 PWR 26-Port Configuration Manual page 792

65
VLAN-VPN Configuration
Wh n configuring VLAN-VPN, e
VLAN-VPN Overview
VLAN-VPN Configuration
Displaying and Maintaining VLAN-VPN Configuration
VLAN-VPN Configuratio
VLAN-VPN Overview
Introd uction to VLAN-VPN
Virtual private network (VPN) is a new technology that emerges with the expansion of the Internet. It can
be used for establishing private networks over the public network. With VPN, you can
packets on the client or the access end of the service provider in specific ways, establish dedicated
tunnels for user traffic on public network devices, and thus improve data security.
VLAN-VPN feature is a simple yet flexible Layer 2 tunneling technology. It tags private network packets
with outer VLAN tags, thus enabling the packets to be transmitted through the service providers'
backbone networks with both inner and outer VLAN t
transmitted by their outer VLAN tags (that is, the VLAN tags of public networks), and t
tags are treated as part of the payload.
Figure 65-1 shows the structure of single-tagged and double-tagged Ethernet frames.
Figure 65-1 Single-tagged frame structure vs. double-tagged Ethernet frame structure
Compared with MPLS-based Layer 2 VPN, VLAN-VPN has the following features:
It provides Layer 2 VPN tunn
VLAN-VPN can be implemented through manual configuratio
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.
go to these sections for information you are interested in:
n Example
els that are simpler.
65-1
ags. In public networks, packets of this type are
n. That is, signaling protocol-related
specify to process
he inner VLAN