# Wolz

- Broadcast Wake on Lan (WoL) magic packet to network devices in the local network.
- WoL only works if the target network interface supports it and is not in low power mode.
- Check [arch wiki](https://wiki.archlinux.org/title/Wake-on-LAN) on this subject to setup your device to Wakup on LAN.

## Usage

Run `wolz` to view the help text.

## Troubleshooting

This tool broadcasts the magic packet to the broadcast address (and port 9) of all networks the physical interfaces connect to.

Install `tcpdump` to inspect the network traffic on the receiving node. And execute the tool from the source node.

```bash
$> # Update `enp42s0` to your interface name.
$> sudo tcpdump -i enp42s0 udp and port 9 -n -XX
$>
$> # Sample output for mac aa:bb:cc:dd:ee:ff
18:56:47.573848 IP 192.168.0.10.34801 > 192.168.0.255.9: UDP, length 102
0x0000:  ffff ffff ffff dca6 324f e820 0800 4500  ........2O....E.
0x0010:  0082 adf8 4000 4011 0a19 c0a8 000a c0a8  ....@.@.........
0x0020:  00ff 87f1 0009 006e 8b27 ffff ffff ffff  .......n.'......
0x0030:  aabb ccdd eeff aabb ccdd eeff aabb ccdd  ................
0x0040:  eeff aabb ccdd eeff aabb ccdd eeff aabb  ................
0x0050:  ccdd eeff aabb ccdd eeff aabb ccdd eeff  ................
0x0060:  aabb ccdd eeff aabb ccdd eeff aabb ccdd  ................
0x0070:  eeff aabb ccdd eeff aabb ccdd eeff aabb  ................
0x0080:  ccdd eeff aabb ccdd eeff aabb ccdd eeff  ................
```

To debug TCP packets intended to wolz-daemon, run

```
$> sudo tcpdump -i lo tcp and port 21367 -n -XX
```