How NAT Differs from ICS
Applies To: Windows 7, Windows Server 2008 R2
Internet Connection Sharing (ICS) provides a network translation capability that is an alternative to that provided by network address translation (NAT) in RRAS. ICS is typically used by small networks that have two to ten computers. Because ICS and RRAS NAT share common drivers, they cannot coexist on the same network.
Both ICS and NAT provide translation, addressing, and name resolution services to SOHO hosts.
ICS is designed to provide a single step of configuration (a single check box) in order to provide a translated connection to the Internet for all of the computers on the SOHO network. However, when enabled, ICS does not allow configuration beyond the configuration of services and ports on the SOHO network. For example, ICS is designed for a single IP address obtained from an Internet service provider (ISP) and does not allow you to change the range of IP addresses allocated to SOHO hosts.
The RRAS NAT component is designed to provide maximum flexibility in configuring the RRAS server to provide a translated connection to Internet. The NAT routing protocol component requires more configuration steps; however, each step of the configuration can be customized. Most of the configuration can be accomplished using the RRAS Setup Wizard. The NAT routing protocol component allows for ranges of IP addresses from an ISP and the configuration of the range of IP addresses allocated to SOHO hosts.
The following table summarizes the features and capabilities of ICS and the NAT routing protocol component.
| ICS | RRAS NAT |
|---|---|
Single check box configuration |
Manual or wizard-driven configuration |
Single public IP address |
Multiple public IP addresses |
Fixed address range for SOHO hosts |
Configurable address range for SOHO hosts |
Single SOHO interface |
Multiple SOHO interfaces |
Note
ICS is a feature designed to connect SOHO networks to the Internet. RRAS NAT is designed to connect small to medium business networks to the Internet. Neither ICS nor RRAS NAT is designed to:
- Directly connect SOHO networks.
- Connect networks within an intranet.
- Directly connect branch office networks to a corporate network.
- Connect branch office networks to a corporate network over the Internet.