Configuring Multiple Access Points

Once you get them wired up, configuring multiple Access Points isn't as hard as you might think. Just follow these three basic steps:

1) Set the AP SSID

If you don't want to control which AP your client connects to, set all your APs to the same SSID. But if you want to force your client to connect to specific APs, then set different SSIDs.

Since most wireless clients are very "sticky" and tend to stay associated to the first AP they encounter, even when APs with stronger signals are available, different SSIDs are recommended for small wireless networks with users who know how to switch between wireless networks.

2) Set adjacent AP's to non-overlapping channels

For 802.11b, the usual practice is to use only channels 1, 6, and 11, which are said to be the only non-overlapping frequencies. WLAN startup Cirond Technologies, however, asserts in a whitepaper that channels 1,4, 8, and 11 can be used without significant performance degradation. You can probably use either method and get satisfactory results.

3) Use Static IPs

Although most APs will automatically grab IP address info from your LAN's DHCP server, I recommend you manually assign the IP address info to all APs. Use IP addresses in your LAN's subnet that are above the range of addresses handed out by your DHCP server. That way you always know where to reach out and touch any APs that need attention. And if your expansion AP happens to have its own built-in DHCP server - shut it off! Only one DHCP server per LAN, please!

Example: Your LAN's main router has an IP address of 192.168.1.1 (subnet mask 255.255.255.0) with its DHCP server set to hand out 20 addresses starting at 192.168.1.100.

To make things easy, assign an address of 192.168.1.254 (subnet mask 255.255.255.0) to your first remote AP, and decrement the number by 1 for each additional AP.