Problem with WOL and scanning in another VLAN

[info-path]

I have UpSnap installed in Docker as a HOST, scanning and WOL works correctly if I am in the same subnet, e.g. 192.168.1.0/24.

But WOL doesn't work if I specify a PC from a different subnet, e.g. 192.168.5.2, and neither does scanning the 192.168.5.0/24 subnet. The Firewal is disabled, pinging to 192.168.5.0/24 from terminal on Ubuntu with Docker and UpSnap works.

My docker-compose:

services:
  upsnap:
    container_name: upsnap
    image: ghcr.io/seriousm4x/upsnap:3
    network_mode: host
    restart: unless-stopped
    volumes:
      - ./data:/app/pb_data
    environment:
      - TZ=Europe/Berlin
      - UPSNAP_INTERVAL=@every 5s # Sets the interval in which the devices are pinged
      - UPSNAP_SCAN_RANGE=192.168.0.0/16 # Scan range is used for device discovery on local network

What am I doing wrong? Can I use WOL on another subnet?

[seriousm4x]

Sending magic packets to another subnet works if you set the netmask in your device settings correctly. If you are unsure just set it to 255.255.255.255. This will send the packet to all subnets. If it's still not waking up, the issue is probably somewhere else in your network.

For scanning, try to use nmap manually and see if it finds your devices: nmap -sn SCAN_RANGE --host-timeout 500ms.
Thats the command I use internally.

[info-path]

Hello seriousm4x, I still can't figure it out.

This doesn't work in UpSnap either:

IP: 192.168.50.2
MAC: 1C:69:7A:63:80:35
Netmask: 255.255.255.255

Any attempt at a Network scan in the 192.168.50.0/24 range is unsuccessful. No record will be displayed. But WOL and NMAP works if I try it directly from HOST (Ubuntu with Docker and UpSnap container. Container has as network_mode: host):

Docker host IP 192.168.1.30

nmap works:

path@docker:~$ nmap -sn 192.168.50.0/24 --host-timeout 500ms
Starting Nmap 7.80 ( https://nmap.org ) at 2024-01-15 07:57 CET
Nmap scan report for 192.168.50.1
Host is up (0.00078s latency).
Nmap scan report for 192.168.50.2
Host is up (0.00067s latency).
Nmap scan report for jellyfin (192.168.50.15)
Host is up (0.00047s latency).
Nmap scan report for jellyfin-x (192.168.50.16)
Host is up (0.00046s latency).
Nmap done: 256 IP addresses (4 hosts up) scanned in 2.21 seconds

wol works:

path@docker:~$ wakeonlan 1C:69:7A:63:80:35
Sending magic packet to 255.255.255.255:9 with 1C:69:7A:63:80:35

There doesn't seem to be a network problem. Any idea how to fix this? I hope there will be no problem in my UDM Pro router.

#EDIT:
On the other hand, even though this works:
wakeonlan 1C:69:7A:63:80:35

this entry doesn't work:
wakeonlan -i 192.168.50.2 1C:69:7A:63:80:35

#EDIT 2:
I tried to install another application from another author: GPTWOL (https://github.com/Misterbabou/gptwol). In this application After entering IP and MAC I woke up the PC successfully. I assume it uses WOL in a different way?

#EDIT 3:
Ha! I restarted the UpSnap container and the WOL for mask 255.255.255.255 started working! That's very interesting, before the mask change had no effect. Network scan still doesn't work for the other subnet, but WOL finally does! Sorry for so much spam.

#EDIT 4:
I don't know why, but I can't wake up the server again. A few minutes after shutting down the server, WOL does not work for UpSnap. GPT WOL works. It's pretty confusing.