IPv4 Routing

Applies To: Windows 7, Windows Server 2008 R2

Routing is the forwarding of traffic destined to a location on a network from a source host to a destination host by using routers.

Today, the majority of network traffic worldwide is over Internet Protocol version 4 (IPv4) networks, and most user-initiated traffic across IPv4 networks is unicast traffic. IP routing occurs on all IP networks connected by routers, including:

  • The Internet.

  • An IP intranet not connected to the Internet.

  • Intranets that connect to the Internet or to each other through the Internet.

Any Windows network supports IP routing. These include networks that use only hardware routers, networks that use software-based routers such as RRAS included in Windows Server, or networks that use a combination of hardware and software routers.

Unicast routing handles network traffic that has a single host as the destination. Multicast routing handles network traffic that is addressed to a group of hosts, possibly spread across many different networks or subnets.


Windows Vista, Windows 7, Windows Server 2008, and Windows Server 2008 R2 also fully support Internet Protocol version 6 (IPv6). For more information about IPv6 and routing IPv6 network traffic, see IPv6 Addressing and IPv6 Routing.

Additional references

For more information about routing IPv4 network traffic, see the following topics: