# 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

## Usage

Run `wolz` to view the help text.

## Troubleshooting

This tool broadcasts the magic packet to the limited broadcast address 255.255.255.255 and port 9.

Install `tcpdump` to inspect the network traffic published to the limited broadcast address (255.255.255.255) and port 9

```bash
$> # Update `enp42s0` to your interface name.
$> # To find out the interface to which the kernel 
$> # routes the packets to, do
$> # ip route get 255.255.255.255
$> sudo tcpdump -i enp42s0 udp and host 255.255.255.255 and port 9 -n -XX
$>
$> # Sample output for mac 04:7c:16:6e:c0:2f 
0x0000:  4500 0082 6153 4000 4011 ceb6 0a60 0002  E...aS@.@....`..
0x0010:  ffff ffff 8bd0 0009 006e b739 ffff ffff  .........n.9....
0x0020:  ffff 047c 166e c02f 047c 166e c02f 047c  ...|.n./.|.n./.|
0x0030:  166e c02f 047c 166e c02f 047c 166e c02f  .n./.|.n./.|.n./
0x0040:  047c 166e c02f 047c 166e c02f 047c 166e  .|.n./.|.n./.|.n
0x0050:  c02f 047c 166e c02f 047c 166e c02f 047c  ./.|.n./.|.n./.|
0x0060:  166e c02f 047c 166e c02f 047c 166e c02f  .n./.|.n./.|.n./
0x0070:  047c 166e c02f 047c 166e c02f 047c 166e  .|.n./.|.n./.|.n
0x0080:  c02f                                     ./
```

If you have VPN enabled, depending on the configuration the kernel might route it to the tunnel interface, and the tool will not work.

To debug TCP packets intended to wolz-daemon, run

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