System information

4. Disconnect the AP which your laptop is associated with and see how soon you can roam to
the other AP. Normally 1 ping loss is observed when roaming. (Note: Please see section
3.6.1 below for an alternative mechanism for simulating a roam)
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: You will not be able to seamlessly roam between AP1 and AP2 using the other SSIDs
since these are not configured for L3 Tunneling and these APs are on different IP subnets which
will require the client to obtain a new IP address on a non tunneled SSID.
3.6.2. 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.
1. Use your laptop to test wireless connection by associating to the “L3-Tunnel” SSID Network,
and check if you’re getting the IP address correctly from the Unified Switch’s DHCP server
on the Tunnel subnet.
2. Once wireless connectivity is confirmed, you can check which AP your laptop connects to
[ WLAN/ Monitoring/ Client/ Associated Clients ].
3. Start to Ping one of the LAN interfaces (172.17.5.253 or .254) or its loopback interface
( 192.168.10.254 ).
4. Enable AP “debug” mode to allow direct Telnet access to the APs CLI
[ WLAN/Administration/AP Management/Advanced ].
5. Open a Telnet session to the IP address of the AP which your client has associated with and
login.
6. 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.
3.6.3. 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 client’s
decision to roam an antenna can be connected to one of the APs after you have already associated
with the other.
3.7. Logs & Traps
The administrator can enable or disable SNMP traps sent from the Unified Switch and the trap
destinations. The traps can be enabled or disabled by traversing to Administration Æ Advanced
Configuration Æ Global in the WLAN tab. In managed mode the AP doesn’t generate any
traps. The list below shows all the possible traps generated on the Unified Switch: