Using a Wireless Router as an Access Point
Members often ask about how to add wireless capabilities to their existing network, which already uses a wired router. See note after 2b, for attaching a Wifi Router as an AP/switch to an existing wifi network. Since it is often less expensive than an access point, a wireless router may make sense.
1. Using a PC wired into the current router, unplug it from the wired connection and plug into a LAN port on the secondary router. Access the secondary router using your browser via its default LAN IP address and default password. Since the PC was attached to the previous router you will have tell the PC to obtain a LAN IP from the new device. Use 'winipcfg' in win9x or 'ipconfig release/renew' with W2K/XP on the PC.
2. On the secondary router (hereafter called the AP)
a. change the default password to a minimum combination of 8 letters/numbers/symbols.
b. Change the ESSID to a unique name and make all the necessary wireless configurations.
Note: If attaching a WiFi router as an AP/switch to an existing wifi network, one should keep the ESSIDs the same for seamless roaming, or separate if one wants to manually decide which AP to connect to. If you decide to use the existing ESSID as your existing wireless network, your security settings should be the same. Also, ensure channel separation (1-6-11 common for three devices). Two wireless AP on the same channel does not work very well.
3. In the AP, go to the LAN setup page:
a. Turn DHCP serving OFF on the AP (i.e secondary router being configured as AP). This is necessary so that your DHCP clients obtain correct settings (with correct gateway) from the primary router instead of the incomplete/erroneous one from the AP.
b. Change the LAN IP of the AP from its default so that it lies within the subnet of the primary router but preferably outside the dynamic LAN IP range of the primary router. (examples below) Note: This is not a requirement, but keeping everything in the same IP range can make administration and file sharing easier.
c. Disable or turn RIP off, if there is that option.
d. Disable or turn off Universal Plug and Play (UPnP) support (if any).
4. Plug the PC back into the wired connection and repeat the process of getting new LAN IP. A reboot of the PC may be needed.
5. Plug the AP into the primary router, LAN port TO LAN port directly or via switch/patch panel etc. Leave the WAN port of AP disconnected.
6. It may be necessary to reboot one or both routers but one should be able to assign LAN IPs wirelessly and connect at this point, ensuring WiFi card setup properly.
LAN IP 192.168.1.1
old Dynamic DHCP Pool 192.168.1.2 - 192.168.1.xx
subnet mask 255.255.255.0
Will need to change Dynamic DHCP pool
new DCHP Pool 192.168.1.33 - 192.168.1.xx (for example)
Subnet mask 255.255.255.0
Secondary Router (our Access Point)
old LAN IP 192.168.0.1 -or any other default
Will need to change LAN IP to be within subnet of primary.
new LAN IP 192.168.1.2
Subnet mask 255.255.255.0 Using a Wireless Router as an Access Point Wireless Networking Forum FAQ | DSLReports.com, ISP Information
Or you could just purchase a dedicated access point which in my opinion is much easier to set up.