OpenWRT apps
User manuals and descriptions of some OpenWRT

Watchcat
Watchcat - Network watchdog utility
"Watchcat is a ping-watchdog utility that allows you to set up rules for when a ping to a particular host fails."
The following modes of operation are available
- Ping Reboot: reboot the OpenWrt device if a ping to a specific host fails
- Restart Interface: restart a network interface if a ping to a host over that interface fails
- Periodic Reboot: reboot at a set period of time, such as every 24h.
Introduction
Watchcat is a ping-watchdog utility that allows you to set up rules for when a ping to a particular host fails.
The following modes of operation are available:
Ping Reboot : reboot the OpenWrt device if a ping to a specific host fails.
Restart Interface : restart a network interface if a ping to a host over that interface fails.
Periodic Reboot : reboot at a set period of time, such as every 24h.
Parameters
mode - the mode this watchcat instance is in.
 
Ping_reboot
Periodic_reboot
Restart_interface
Run_script
Period - the way this parameter is used depends on the mode watchcat is in.
Periodic Reboot : the interval of time at which to perform the reboot, such as every 24h
Ping Reboot : the longest interval of time without a successful ping before the rule is activated
Restart Interface : the longest interval of time without a successful ping before the rule is activated
(restarts only the interface)
Host to check - In Ping Reboot and Restart Interface modes, IP address or the host name to ping
Check Interval - The time duration to ping the host
every 10 seconds would be: 
10 or 
10s
every 5 minutes would be: 
5m
every 1 hour would be: 
1h
every week would be: 
7d
Ping Packet Size - The size of packet to use for pings.
small - 1 byte
windows - 32 bytes
standard - 56 bytes
big - 248 bytes
huge - 1492 bytes
jumbo - 9000 bytes
Force Reboot Delay - In Ping Reboot and Periodic Reboot modes, the amount of time to try a graceful reboot before a sysreq reboot is activated as a fail safe.
Interface -  The interface to ping via, and also, in Restart Interface mode the one to restart. If unset, it will use the default route's interface