ZyXEL Communications ZyWALL 1000 User Manual

ZyWALL USG 1000 User’s Guide

This chapter explains how to set up and maintain L2TP VPNs in the ZyWALL. See 

 for related information on these screens.

L2TP VPN lets remote users use the L2TP and IPSec client software included with their 
computers’ operating systems to securely connect to the network behind the ZyWALL. The 
remote users do not need their own IPSec gateways or VPN client software. 

Figure 237   L2TP VPN Overview

The Layer 2 Tunneling Protocol (L2TP) works at layer 2 (the data link layer) to tunnel 
network traffic between two peers over another network (like the Internet). In L2TP VPN, an 
IPSec VPN tunnel is established first (see 

 for information on IPSec) 

and then an L2TP tunnel is built inside it. 

"

At the time of writing the L2TP remote user must have a public IP address in 
order for L2TP VPN to work (the remote user cannot be behind a NAT router 
or a firewall). 

You must configure an IPSec VPN connection for L2TP VPN to use (see 

 for details). The IPSec VPN connection must:

• Be enabled.