System information

5. You can repeat step 2-4 and observe your laptop roam from AP to AP without changing IP,
and with limited packet loss. (Note: If you use this method for simulating a roam, when you
roam back to the original AP the client was associated with a re-authentication with the
RADIUS server will be required since power-cycling the AP will cause it to lose its security
key cache.)
4.6.2. Simulated Roam via Disabling Radios
The following procedure shows how to simulate a roam by disabling the radio the client is
currently associated with. By using this method, the link between the AP and the Unified Switch
will not go down and therefore the local route will not be removed and the above mentioned
routing loop issue will not happen.
7. Use your laptop to test wireless connection by associating to the “D-LINK-NET1” SSID
Network, and check if you’re getting the IP address correctly from the Unified Switch’s
DHCP server on the Tunnel subnet after properly authenticating via WPA2.
8. Once wireless connectivity is confirmed, you can check which AP your laptop connects to
[ WLAN/ Monitoring/ Client/ Associated Clients ].
9. Start to Ping one of the LAN interfaces (172.17.5.253 or .254) or its loopback interface
( 192.168.10.254 ).
10. Enable AP “debug” mode to allow direct Telnet access to the APs CLI
[ WLAN/Administration/AP Management/Advanced ].
11. Open a Telnet session to the IP address of the AP which your client has associated with and
login.
12. Disable the radios with this command: “set radio all status down”. You will observe the
client roam to the other AP with minimal ping loss.
4.6.3. Real Roam
A real-world roam involves physically moving from near one AP to the other such that your
client will automatically associate with the closer AP of stronger signal strength. This is best
shown when the APs are adequately separated to allow signal strength decrease as you move
away one AP and signal strength increase from the other AP as you move nearer. Wireless VoIP
phones are the best clients to use since they are tuned to roam if a stronger signal is detected from
another nearby AP. PC clients are not tuned for these rapid roams and therefore will often allow
the signal strength to decrease significantly before selecting a stronger signal AP to associate
with – this can cause traffic loss simply associated with a weak signal. To facilitate the clients
decision to roam an antennae can be connected to one of the APs after you have already
associated with the other.
4.7. WLAN Visualization
The WLAN Visualization component is an optional feature that graphically shows information
about the wireless network. WLAN Visualization uses a Java applet to display D- Link WLAN
Controller Switches, D- Link Access Points, other access points, and associated wireless clients.
The WLAN Visualization tool can help you visualize where the APs are in relationship to the
building.
You can upload one or more custom images to create a background for the graph. Then, you
place the WLAN components discovered by the switch on the graph to help provide a realistic