ZyXEL Communications 200 Series 用户手册

ZyWALL USG 100/200 Series User’s Guide

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 295   L2TP VPN Overview

• Use the L2TP VPN screen (see 

) to configure the ZyWALL’s 

L2TP VPN settings. 

• Use the L2TP VPN screen (see 

) to display and manage the 

ZyWALL’s connected L2TP VPN sessions. 

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 and then an L2TP tunnel is built inside it. See 

 for information on IPSec VPN.

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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).