S&C Instruction Sheet 461-509
65
Confi guring the Communication Gateway
L2TP Ethernet Configuration
IPSec is often used to secure L2TP packets by providing confi dentiality, authentication,
and integrity. The combination of these two protocols is generally known as L2TP/IPSec.
This type of security tunnel allows the administrator to create a secure tunnel that
encapsulates Ethernet packets from the local Ethernet interface on the communication
gateway to the remote server. The L2TP/Ethernet packets are encapsulated within an
IPSec Security Association to provide authentication, encryption, and integrity protection
for remote communications to the communication gateway. The two endpoints of an
L2TP tunnel are called the LAC (L2TP access concentrator) and the LNS (L2TP network
server). After the
L2TP-Ethernet/IPSec
option is selected from the drop-down menu,
a confi guration dialogue box will open. See Figure 58.
Figure 58. The L2TP Ethernet Configuration dialogue box.
