I’ve been having some issues with setting up a firewall for my Minecraft server network.
I currently rent a dedicated server, on-which I host 6 Minecraft servers and 1 Bungeecord proxy.
After being UUID spoofed, trying to lock it down to prevent any future attacks.

The ports my servers are running on are 25565-25571. With 25565 being the proxy, the only internet facing/online-mode in-which authenticates users accounts. The others are only open to internal ip, as to force traffic through the proxy.

After speaking with my hosting provider, they said to not touch iptables, but to use UFW instead. So I have gone ahead and created the following rules:
Ports 25566-25571 allow only incoming traffic from 127.0.0.1
Port 25565 (bungee proxy) to allow incoming traffic from anywhere.
With outgoing traffic being enabled to anywhere.

From there, all the servers in my bungeecord config look like this:
‘server1’:
address: 127.0.0.1:25566
motd:
restricted: false
However, when trying to connect, it spits out the generic error saying you’ve misconfigured your firewall.

I am completely new to IPTables/UFW and pretty much Linux as a whole. So any help is much appreciated!

Some things to note –
This host I’m through has their own ‘skin’ of pterodactyl, which resets the servers IP in server.properties to 0.0.0.0 each time I start the server. Overwriting any IP I try to set it to.

If I Grep the IPTable rule for each port, there’ll be additional rules, such as:
ACCEPT tcp — 0.0.0.0/0 172.19.0.6 tcp dpt:25570
ACCEPT udp — 0.0.0.0/0 172.19.0.6 tcp dpt:25570