Chapter 4 Dvpn; Dvpn Overview; Introduction To Dvpn; Basic Dvpn Concepts - 3Com 3C13636 Configuration Manual

3Com Router 3000 Ethernet Family
Configuration Guide

4.1 DVPN Overview

4.1.1 Introduction to DVPN

Dynamic virtual private network (DVPN) technology is a kind of technology that
establishes virtual private networks (VPNs) by dynamically acquiring information about
the peers. Adopting a non-broadcast multiple access (NBMA) tunneling mechanism,
DVPN enables devices to encapsulate and transmit DVPN packets with virtual tunnel
interfaces as the end points of DPVN tunnels, and enables devices to learn private
network routes through tunnel interfaces dynamically.
DVPN 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. Therefore, a registered client can acquire information about other
registered clients through the redirect function of the server and then establish separate
sessions with those clients. By registering with the same server, multiple
DVPN-enabled access devices can form a DVPN domain, implementing the
interconnection of the VPNs behind the access devices.

4.1.2 Basic DVPN Concepts

I. DVPN domain
A set of private networks and their routers that are interconnected using DVPN.
II. DVPN access device
A router for building DVPNs across networks. Any router that supports DVPN can be a
DVPN access device.
III. DVPN server
The DVPN access device that acts as the server in a DVPN domain. The other DVPN
access devices must register with the DVPN server before they can access the DVPN
domain. A DVPN sever has these functions:
Store and maintain registration information about DVPN clients.
Authenticate clients that apply for accessing the DVPN domain.
Forward packets between clients with no sessions established, and send redirect
packets to source clients.
Encrypt packets using IPSec.

Chapter 4 DVPN

3Com Corporation
4-1
Chapter 4 DVPN