Internet connection sharing
(also ICS)
Internet connection sharing definition
Internet connection sharing (ICS) is a technique that allows computers to share their internet connection with others. The computer that shares the connection is known as the “host,” acting as a gateway for “client” computers that are connected to it through a local area network (LAN).
Internet connection sharing was originally a feature of Windows 98 SE, where it was appropriately named “Internet Connection Sharing.” It has been present in every subsequent version of the Windows operating system. However, other operating systems (including macOS and Linux) have since implemented their own ICS analogues.
See also: local area connection, wireless local area network, hotspot, DHCP
How internet connection sharing works
To begin with, the ICS feature must be enabled manually in the host computer’s network settings. The host must also be directly connected to the internet (usually through a broadband connection such as DSL or cable) and a local area network containing the client devices.
The host computer performs Network Address Translation (NAT), a process that allows multiple devices on the local network to share a single public IP address. The host assigns private IP addresses to the client devices and keeps track of the translation between private and public IP addresses.
Once the setup has been completed, the host computer serves as an internet gateway. When a client device requests information from the internet, the host forwards the request and shares the response.