Internet Connection Firewall (ICF)/Internet Connection Sharing (ICS)


Provides network address translation (NAT), addressing and name resolution services for all computers on your home network, so they can access the Internet through the shared network- or dial-up- connection.

This service is mainly intended for home networks, and it includes its own DNS- and DHCP-Server, and makes use of the NAT module. If on a corporate network with own DNS-, DHCP-, RASS-Server, then ICS might conflict with these. One should instead use Routing And Remote Access or ISA-Server for providing access to the Internet.

Note with Windows XP this service has been extended with a software firewall that can block incoming traffic. The firewall is activated by default when running WinXP Service Pack 2, and will provide enough protection for most users, but if also wanting full control of outgoing traffic, then a 3rd party firewall is required.

Related Setting up Internet Connection Sharing
Related Setting up WinXP Internet Connection Firewall (ICF)
Related How to repair the Windows Firewall service if it will not start

More Info MS KB234815
More Info MS KB250603
More Info MS KB310563
More Info MS KB310563
More Info MS KB827328

  • Disabled, if not sharing your internet connection AND not using the builtin firewall.
  • Automatic, if using the builtin firewall or connection sharing.
Default State:
  • WinXP: Automatic.
  • Win2k3: Disabled.
Process Name:
  • None