JSI Tip 2259. ICS may not work reliably if the DNS or DHCP service is installed on the same computer.JSI Tip 2259. ICS may not work reliably if the DNS or DHCP service is installed on the same computer.

ICS (Internet Connection Sharing) is a Windows 2000 implementation of NAT (Network Address Translation). ICS sets up a mini DHCP scope and DNS Proxy service.

When these services start, they bind to the same TCP ports as DNS and DHCP, causing conflicts.

Instead of using ICS on a DNS or DHCP server, use RRAS to configure NAT.