Starting from firmware release 3.0 users can now make their Wireless LAN service dependent on the reachability of some critical server on the network.
To configure and enable this feature, enter the IP address or hostname of the server in the 'Monitored Host' section of the advanced configuration of a WLAN:
that device will be periodically pinged approximiately every mibute by the Access Point now. If there is no ping response to any of the ping requests, 3 more successive ping attempts are made (5 seconds apart) to ensure that the monitored host is really unreachable. If it is, then the WLAN is taken out of service.
The monitoring of the external host continues until it is reachable again, at which point the WLAN is brought back into service.
This feature can be used to monitor any server whose reachability is criticial to be able to provide service to wireless clients. This would typically be one of:
- a DHCP server
- a DNS server
- the default gateway on the network
- an external captive portal server used for guest access redirection
etc.
It is also useful when a mesh AP loses connection to the network.
Instead of still beaconing an SSID which is not providing connectivity to clients, the WLAN would be disabled, and clients would either see there is no service, or connect to another AP which might have reachability, or another WLAN which does not require this monitored resource to be up.
The net result is a much better user experience, users will no longer be stranded on an AP: the wifi signal looks good, but network connectivity is'nt there.