I have done a lot of work with small and mid-sized wired networks, but I have only worked with single access point wireless networks until recently. The first thing I noticed is that the documentation on configuring wireless networks for multiple access points is poor. So, with the idea of helping others, here is what I’ve figured out.
For the purposes of my examples, I’m assuming that the clients will be accessing the wireless access point (WAP) by using a shared-key (password) and that all users will be using the same key. The use of 802.1x for authentication is beyond the scope of what I’m dealing with.
Vendors use slightly different terminology for the same scenario. I've attempted to use generic terminology that is similart to most vendors.
You can often use just the WAP functionality of a wireless router. However, many of these do not have as many wireless configuration options. If you use a wireless router as a second WAP, be sure that you disable DHCP on the device. Only the internal IP address of the device will need to be configured.
Scenario 1 – Wired WAPs
All WAPs should be configured with the same SSID (network name) and key but be using different channels. Wireless clients are configured with a single SSID and key. It is the responsibility of the client to select the appropriate WAP based on signal strength. If the client moves while it is connected roaming should occur with very little interruption as the connection changes from one WAP to the next.
Scenario 2 – Wireless Repeater
Some devices support a protocol called Wireless Distribution Service to support this. However, this protocol has many interoperability problems between vendors. So, don’t count on it.
The WAPs should be both be configured with the same SSID and key. The WAP configured as a wireless repeater should not be connected via Ethernet to the main network. If you do connect the wireless repeater to the Ethernet network, you may cause all devices on the network to get duplicate IP address errors. The duplicate address errors in the Windows event log will indicate the MAC address of the WAP.
Scenario 3 – Wireless Bridge
A WAP in bridge mode is connected to each wired network. Each WAP is configured with the same SSID. You also typically have the option to allow wireless clients to connect to each WAP.