D-Link DFL-1600 User Manual page 259

22.2. PPTP/ L2TP 239
6. User Authentication Rule
Next step is to configure the user authentication rule to use for au-
thentication.
User Authentication User Authentication Rules Add
User Authentication Rule:
Enter the following:
Name: L2TPUARule
Agent: PPP
Authentication Source: Local
Interface: L2TPServer
Originator IP: 0.0.0.0/0 (all-nets)
Terminator IP: 10.0.0.1 (The IP the L2TP server is listening on)
Authentication Options/Local User DB: UserDB (The user database
created earlier)
PPP Agent Options: Select the authentication protocols to support.
(Default setting is to support all authentication protocols)
Then click OK
7. IP Rules
The final step is to set up a rule to allow traffic from L2TP clients
onto the LAN network.
Rules IP Rules Add IP Rule:
Enter the following:
Name: FromL2TPClients
Action: Allow
Service: Any
Source Interface: L2TPServer
Source Network: 192.168.1.10-192.168.1.20
Destination Interface: LAN
Destination Network: 192.168.1.0/24 (Network on LAN interface)
Then click OK
If the L2TP clients should be able to access external resources (such
as the Internet for example) a NAT rule has to be configured as well.
When the configuration is saved and activated, it should be possible
for L2TP/IPsec clients to connect to the L2TP/IPsec server on 10.0.0.1 on
the WAN interface.
D-Link Firewalls User's Guide