3Com Router 3000 Ethernet FamilyConfiguration Guide Table of Contents3Com Corporationii2.3.13 Disconnecting an L2TP Connection.................................................................... 2-222.3.14 Enabling/Disabling Flow Control Function of Tunnel .......................................... 2-232.4 Displaying and Debugging L2TP ..................................................................................... 2-232.5 L2TP Configuration Example........................................................................................... 2-242.5.1 NAS-Initialized VPN .............................................................................................. 2-242.5.2 Client-Initialized VPN ............................................................................................ 2-262.5.3 Interconnecting Single User with Headquarters via Router .................................. 2-272.5.4 L2TP Multi-Instance Networking Application ........................................................ 2-292.5.5 Using LAC as L2TP Client .................................................................................... 2-332.5.6 Complex Network Design...................................................................................... 2-352.6 L2TP Troubleshooting ..................................................................................................... 2-35Chapter 3 Configuration of GRE .................................................................................................. 3-13.1 Brief Introduction to GRE................................................................................................... 3-13.2 GRE Configuration............................................................................................................. 3-43.2.1 Creating Virtual Tunnel Interface ............................................................................ 3-43.2.2 Setting Encapsulation Mode ................................................................................... 3-53.2.3 Specifying Tunnel Source ....................................................................................... 3-53.2.4 Specifying Tunnel Destination................................................................................. 3-63.2.5 Assigning Network Address to Tunnel Interface ..................................................... 3-63.2.6 Configuring End-to-End Verification on Both Ends of Tunnel................................. 3-73.2.7 Setting Identification Key of Tunnel Interface ......................................................... 3-73.2.8 Configuring Routing via Tunnel............................................................................... 3-83.2.9 Configuring the keepalive function .......................................................................... 3-83.3 Displaying and Debugging GRE ........................................................................................ 3-93.4 Typical Configuration Examples of GRE ........................................................................... 3-93.5 GRE Troubleshooting ...................................................................................................... 3-11Chapter 4 DVPN ............................................................................................................................. 4-14.1 DVPN Overview ................................................................................................................. 4-14.1.1 Introduction to DVPN .............................................................................................. 4-14.1.2 Basic DVPN Concepts ............................................................................................ 4-14.1.3 Operation of DVPN ................................................................................................. 4-34.1.4 Basic Network Structure.......................................................................................... 4-54.1.5 Traditional VPN versus DVPN ................................................................................ 4-54.1.6 Extended DVPN Function ....................................................................................... 4-84.2 DVPN Configuration .......................................................................................................... 4-94.2.1 Configuring a DVPN Server (Basic Configuration) ............................................... 4-104.2.2 Configuring a Client (Basic Configuration)............................................................ 4-124.2.3 Configuring the Tunnel Interface........................................................................... 4-144.2.4 Configuring a DVPN Class.................................................................................... 4-174.2.5 Configuring a DVPN Policy ................................................................................... 4-204.2.6 Displaying and Debugging DVPN ......................................................................... 4-244.3 Configuration Example .................................................................................................... 4-24
