3Com Switch 8800 Family IPsec Module Configuration and Command reference Guide

DVPN

Introduction to DVPN

Overview Dynamic virtual private network (DVPN) technology is a kind of technology that

establishes virtual private networks (VPN) by dynamically acquiring the information

about the peers. DVPN adopts a NBMA-type Tunnel mechanism, which enables

devices to encapsulate and transmit packets with Tunnel interfaces as the end

points of DPVN Tunnels and enables devices to learn routes of private networks

through Tunnel interfaces dynamically. (NBMA: non-broadcast multiple access)

DVPN technology also adopts a client-server model to overcome the drawbacks

that the traditional VPN technology suffers from. By registering with a server,

clients store their information on the server. So a registered client can then acquire

information about other registered clients through the redirecting function the

server provides to establish separate sessions with corresponding clients. By

registering with the same server, multiple DVPN-enabled access devices can form a

DVPN domain to have VPNs connected to these access devices interconnected.

Basic DVPN Elements DVPN domain

A set of private networks and their security gateways and routers that are

interconnected using DVPN.

DVPN access device

Routers or security gateways in a network that are used to form DVPN domains.

Any router or security gateway that supports DVPN technology can be a DVPN

access device.

DVPN Server

DVPN access device that operates as the server in a DVPN domain. DVPN access

devices must register with the DVPN server before they can access a DVPN

domain. Functions of DVPN severs are as follows.

■ Storing and maintaining registering information about DVPN clients

■ Authenticating clients that apply for accessing the DVPN domain

■ Forwarding packets between clients with no sessions established in between,

and sending redirecting packets to source clients

■ Encrypting packets using IPsec

DVPN Client

DVPN access device that operates as client in a DVPN domain. A device must

successfully register with the DVPN server to access a DVPN domain. Functions of

DVPN client are as follows.