ISA Server 2006, ISA Server 2004, Microsoft Forefront Threat Management Gateway Medium Business Edition, or Windows Essential Business Server 2008 helps provide secure
site-to-site virtual private network (VPN) functionality by using the following
three methods:
- Internet Protocol security (IPSec) tunnel mode
- Layer Two Tunneling Protocol (L2TP) over IPSec
- Point-to-Point Tunneling Protocol (PPTP)
Two common site-to-site VPN scenarios are:
- The site that you are connecting to is using a third-party
product as its VPN server. In this scenario, use the IPSec tunnel mode
method.
- The site that you are connecting to is using ISA Server
2006, ISA Server 2004, Microsoft ISA Server 2000, Microsoft Windows Server
2003, Microsoft Windows 2000 Server, Microsoft Forefront Threat Management Gateway Medium Business Edition, or Windows Essential Business Server 2008 as its VPN server. In this scenario, use
the L2TP over IPSec method or use the PPTP method. Of these two methods, we
consider the L2TP over IPSec method to be more secure.
To view detailed solutions for each of these scenarios, see the
"Site-to-Site VPN in ISA Server 2004" document. To download this document,
visit the following Microsoft Web site: