Chapter 17 System Administration : PPTP and L2TP : L2TP configuration overview : Enabling L2TP and specifying an address range
  
Enabling L2TP and specifying an address range
The L2TP address range specifies the range of addresses reserved for remote clients. When a remote client connects to the FortiGate unit, the client is assigned an IP address from this range. Afterward, the FortiGate unit uses the assigned address to communicate with the remote client.
The address range that you reserve can be associated with private or routable IP addresses. If you specify a private address range that matches a network behind the FortiGate unit, the assigned address will make the remote client appear to be part of the internal network.
To enable L2TP and specify the L2TP address range, use the config vpn l2tp CLI command.
The following example shows how to enable L2TP and set the L2TP address range using a starting address of 192.168.10.80 and an ending address of 192.168.10.100 for an existing group of L2TP users named L2TP_users:
config vpn l2tp
set sip 192.168.10.80
set eip 192.168.10.100
set status enable
set usrgrp L2TP_users
end
See Also
Authenticating L2TP clients
Defining firewall source and destination addresses
L2TP configuration overview
PPTP and L2TP