Network protocols function at the OSI model Layer 3 (the Network layer) and Layer 4 (the Transport layer). Network protocols are responsible for transporting data across an internetwork. They are responsible for reliable communication as well. The only network protocol installed by default in Windows 7 is TCP/IP, both version 4 and version 6 (called IPv4 and IPv6).

Transmission Control Protocol/Internet Protocol (TCP/IP) is the most commonly used network protocol. It is a suite of protocols that have evolved into the industry standard for network, intranet, and Internet connectivity. The main protocols providing basic TCP/IP services include Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP), and Internet Group Management Protocol (IGMP).

To configure a TCP/IP client, you must specify an IP address (also known as the logical address), subnet mask, and default gateway (if you're going to communicate outside your local network). Depending on your network, you might want to configure a DNS server, domain name, or maybe even a WINS server.

This section describes the following configuration concepts of IPv4:

• IP Addresses
• Subnet Masks
• Default Gateways
• DNS
• WINS
• Methods for Configuring IP
• Essential IPv4 Utilities
• Troubleshooting IPv4