Billion BiPAC 8900X R3, User Manual, Page: 185 / 261

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L2TP
The Layer 2 Tunneling Protocol (L2TP) is a Layer2 tunneling protocol for implementing virtual
private networks.
L2TP does not provide confidentiality or strong authentication by itself.
IPsec is often used to secure
L2TP packets by providing confidentiality, authentication and integrity. The combination of these two
protocols is generally known as L2TP/IPsec
.
In L2TP section, both pure L2TP and L2TP/IPSec are supported. Users can choose your preferable
option for your own needs.
Note: 4 sessions for Client and only one for Server respectively.
L2TP Server
In L2TP session, users can set the bassic parameters(authentication, encyption, peer address, etc)
for L2TP Server, and accounts in the page of VPN Account. They both constitutes the complete
L2TP Server settings.
L2TP: Select Enable to activate L2TP Server. Disable to deactivate L2TP Server.
WAN Interface: Select the exact WAN interface configured as source for the tunnel. Select different
interfaces, you will decide whether to use L2TP over IPSec or the pure L2TP.
L2TP over IPSec, Select “Default or IPSec Tunnel” only when there is IPSec for L2TP rule in
place.
Pure L2TP, Select Default (there is no IPSec for L2TP in place) or other interface to activate
the pure L2TP.
Auth. Type: The authentication type, Pap or Chap, PaP, Chap. When using PAP, the password is
sent unencrypted, whilst CHAP encrypts the password before sending, and also allows for
challenges at different periods to ensure that an intruder has not replaced the client.
IP Addresses Assigned to Peer: 192.168.1.x: please input the IP assigned range from 1~ 254.
Tunnel Authentication: Select whether to enable L2TP tunnel authentication. Enable it if needed