Managing your IP addresses

The first decision you need to make when dealing with IP addresses in your wireless network is whether you want to let your router take care of everything or manually assign the addresses yourself.

Most people just let the router handle the task - using a system called Dynamic Host Configuration Protocol, or DHCP, which is built in to all of the major operating systems and supported by just about every stand-alone Wi-Fi device we know of. The default state of just about any router we've laid our hands on in the past five years has had DHCP turned on, with the router automatically handling IP addresses.

This is a good setting for many folks - it's pretty much foolproof and it works right out of the box more than nine times out of ten. But in some cases, you might want to mess with the status quo. Some instances include:

• You may have a device connected to your wireless network that needs a fixed IP address on the network to work properly.
• You may be doing a lot of file sharing or other computer-to-computer networking within your LAN and want to make permanent bookmarks or shortcuts to your shares on your desktop (or somewhere on your computer). This is a lot easier to do when you know that those shares aren't going to change IP addresses all the time.
  Tip If you're using just Windows or OS X, you can pretty much rely upon the file share names used by those operating systems (like the NetBIOS names used in Windows), which remain constant even when IP addresses change. But if you're mixing and matching other devices (like Linux-based NAS storage devices), it sometimes pays dividends to have fixed IP addresses that you can use.
• You may have multiple segments on your network that need to be configured manually. Perhaps you have more than one AP and you want to configure your network to allow network resource access from all wireless clients - or, conversely, you want to set up your network so that clients attached to some APs have no access to your networked resources.

The following scenarios provide some advice on how you may want to "mess with" your own IP addressing schemes on your routers and APs.