Version 1 (modified by benoitg, 15 years ago)

Add explanation on how to deal with premature client timeout

* Author(s): Benoit Grégoire, you? * last modified: 2006-12-09

This page attempts to document things you should be aware of when building solutions around the WiFiDog gateway.

Client timeout (if yours clients keep timing-out, read this!)

Unlike other solutions, wifidog does not require keeping a specific webpage, script or application to keep the connection open. The gateway will only time out a connection if it doesn't receive any traffic from the client in (CheckInterval? * ClientTimeout) seconds.

To make sure the client doesn't time-out merely because it's idle, the gateway will try to ping every client once every CheckInterval? to generate traffic (it will discard the response). Unfortunately, so called "personal" firewall, have the annoying habit of not only not answering pings, but also completely dropping the packet. This is the reason they are timing out prematurely.

Since teaching everyone the finer points of TCP/IP isn't an option, a workaround is to set an extremely short lease time on the DHCP server serving the gateway's subnet. It has to be shorter than (CheckInterval? * ClientTimeout), which means less than 5 minutes in the default wifidog configuration.