Configuring Local Area Connections

A local area connection is created automatically if a computer has a network adapter and is connected to a network. If a computer has multiple network adapters and is connected to a network, you'll have one local area connection for each adapter. If no network connection is available, you should connect the computer to the network or create a different type of connection, as explained in the "Managing Local Area Connections" section of this tutorial.

Computers use IP addresses to communicate over TCP/IP. Windows Vista provides the following ways to configure IP addressing:

• Manually IP addresses that are assigned manually are called static IP addresses.
  Static IP addresses are fixed and don't change unless you change them. You'll usually assign static IP addresses to Windows servers, and when you do this, you'll need to configure additional information to help the server navigate the network.
• Dynamically A DHCP server (if one is installed on the network) assigns dynamic IP addresses at startup, and the addresses might change over time. Dynamic IP addressing is the default configuration.
• Alternatively (IPv4 only) When a computer is configured to use DHCPv4 and no DHCPv4 server is available, Windows Vista assigns an alternate private IP address automatically. By default, the alternate IPv4 address is in the range from 169.254.0.1 to 169.254.255.254 with a subnet mask of 255.255.0.0. You can also specify a user-configured alternate IPv4 address, which is particularly useful for laptop users.

Configuring Static IP Addresses

When you assign a static IP address, you need to tell the computer the IP address you want to use, the subnet mask for this IP address, and, if necessary, the default gateway to use for internetwork communications. An IP address is a numeric identifier for a computer. IP addressing schemes vary according to how your network is configured, but they're normally assigned based on a particular network segment.

IPv6 addresses and IPv4 addresses are very different, as discussed in the "Working with TCP/IP and the Dual IP Stack" section of this tutorial. With IPv6, the first 64 bits represent the network ID and the remaining 64 bits represent the network interface. With IPv4, a variable number of the initial bits represent the network ID and the rest of the bits represent the host ID. For example, if you're working with IPv4 and a computer on the network segment 10.0.10.0 with a subnet mask of 255.255.255.0, the first three bits represent the network ID, and the address range you have available for computer hosts is from 10.0.10.1 to 10.0.10.254. In this range, the address 10.0.10.255 is reserved for network broadcasts.

If you're on a private network that is indirectly connected to the Internet, you should use private IPv4 addresses. Private network IPv4 addresses are summarized in Table below.

Private IPv4 Network Addressing

All other IPv4 network addresses are public and must be leased or purchased. If the network is connected directly to the Internet and you've obtained a range of IPv4 addresses from your Internet service provider, you can use the IPv4 addresses you've been assigned.