# OpenWRT apps

User manuals and descriptions of some OpenWRT

# Watchcat

### **[Watchcat ](https://openwrt.org/docs/guide-user/advanced/watchcat)- Network watchdog utility**

<p class="callout info">"Watchcat is a ping-watchdog utility that allows you to set up rules for when a ping to a particular host fails."</p>

> 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

1. <span style="text-decoration:underline;">**mode**</span> - the mode this watchcat instance is in.  
    [![obraz.png](https://docs.atreyo.in/uploads/images/gallery/2025-12/scaled-1680-/PUZobraz.png)](https://docs.atreyo.in/uploads/images/gallery/2025-12/PUZobraz.png)
    
    
    - Ping\_reboot
    - Periodic\_reboot
    - Restart\_interface
    - Run\_script
2. <span style="text-decoration:underline;">**Period**</span> - the way this parameter is used depends on the mode watchcat is in.  
    [![obraz.png](https://docs.atreyo.in/uploads/images/gallery/2025-12/scaled-1680-/oxpobraz.png)](https://docs.atreyo.in/uploads/images/gallery/2025-12/oxpobraz.png)
    
    
    - **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)
3. **Host to check** - In Ping Reboot and Restart Interface modes, IP address or the host name to ping
4. **Check Interval** - The time duration to ping the host  
    [![obraz.png](https://docs.atreyo.in/uploads/images/gallery/2025-12/scaled-1680-/04Jobraz.png)](https://docs.atreyo.in/uploads/images/gallery/2025-12/04Jobraz.png)
    
      
    
    - <div class="li">every 10 seconds would be: `10` or `10s`</div>
    - <div class="li">every 5 minutes would be: `5m`</div>
    - <div class="li">every 1 hour would be: `1h`</div>
    - <div class="li">every week would be: `7d`  
        </div>
5. **Ping Packet Size** - The size of packet to use for pings.  
    [![obraz.png](https://docs.atreyo.in/uploads/images/gallery/2025-12/scaled-1680-/xLuobraz.png)](https://docs.atreyo.in/uploads/images/gallery/2025-12/xLuobraz.png)
    
      
    
    - <div class="li">`small` - 1 byte</div>
    - <div class="li">`windows` - 32 bytes</div>
    - <div class="li">`standard` - 56 bytes</div>
    - <div class="li">`big` - 248 bytes</div>
    - <div class="li">`huge` - 1492 bytes</div>
    - <div class="li">`jumbo` - 9000 bytes  
        </div>
6. **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.
7. **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  
    [![obraz.png](https://docs.atreyo.in/uploads/images/gallery/2025-12/scaled-1680-/blLobraz.png)](https://docs.atreyo.in/uploads/images/gallery/2025-12/blLobraz.png)