TABLE OF CONTENTS In the last section, we discussed the procedures required to enable and configure the ISA firewall s VPN server component to allow remote access VPN client PPTP connections. In the following section, we ll build on the configuration we created in the last section and configure the ISA firewall to support a L2TP/IPSec remote access VPN client connection.
We ll perform the following procedures to allow L2TP/IPSec remote access VPN client connections to the ISA firewall:
Issue certificates to the ISA 2006 firewall and VPN clients
Test a L2TP/IPSec VPN connection
Monitor VPN Client Connections
You can significantly improve the level of security on your VPN connections by using the L2TP/ IPSec VPN protocol. The IPSec encryption protocol provides a number of security advantages over the Microsoft Point-to-Point Encryption (MPPE) protocol used to secure PPTP connections. While the ISA firewall supports using a pre-shared key to support the IPSec encryption process, this should be considered a low-security option and should be avoided if possible.
| ISA Firewall Warning | L2TP/IPSec provides data confidentiality, per packet connectionless integrity (proof of the fact that data has not been altered in transit), per packet data origin authentication (proof that the data was sent by the right peer) and replay-attack protection. Connectionless integrity and data origin authentication are commonly known as integrity . L2TP/IPSec provides two levels of authentication: machine (through IKE) and user (PPP authentication). L2TP/IPSec is defined in RFC3193 which specifies an Internet... |
