Connection Issue

[UnholyDecimator]

Server has necessary ports forwarded both through firewall and router.
Server has public IP.

Up until this point, there have been no connection issues.

I could connect from my home, friend who lives far away could also connect no problems.

But here's he weird thing,

From my school:

Cannot connect to server.
Can connect to web admin.

Help, advice?

Edit: I'm guessing it may be a security feature of the school or something wonky with how the networks are interconnected....

[sphinxc0re]

Hello and welcome to the forum

Since you were able to connect to the server from your home PC without problems and your friend was also able to do so, the only thing that could create this issue is the school itself. Most schools nowadays have the typical Minecraft port blocked for some reason. I guess they just don't want you to play in school :-D

So until you wanted to hack into the server system of your school I don't see how to solve this issue.

[UnholyDecimator]

Hello and welcome to the forum

Since you were able to connect to the server from your home PC without problems and your friend was also able to do so, the only thing that could create this issue is the school itself. Most schools nowadays have the typical Minecraft port blocked for some reason. I guess they just don't want you to play in school :-D

So until you wanted to hack into the server system of your school I don't see how to solve this issue.

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There's more to it then that. When I ping my server using: https://dinnerbone.com/minecraft/tools/status/

The server returns an error on the console:
"Client "::ffff:54.158.179.74" uses an unsupported protocol (lengthed, initial  packet 47)"

Also, I am able to connect to other minecraft servers from the school!

Edit: I noticed a pattern. My server isn't technically an actual domain. It doesn't use something like "some.domain.net" it's just ###.###.###.###:####. Could it be that certain networks are set to deny anything that's not a formal domain?

[sphinxc0re]

As far as I know, the vanilla Minecraft server uses a query protocol which is not implemented into the server directly. You can install it as a plugin through: https://github.com/DrMasik/MCServer-Query.git

Wow, that's interesting. Maybe @worktycho knows?

[xoft]

When you try to connect from your school, does the server console show anything relevant?

Perhaps try forwarding an additional, different port than the default minecraft. Usually home NAT devices allow you to port-forward WAN port X to LAN port Y, where X is different to Y. Some ports will most likely be blocked by your ISP, but perhaps some will work. Try to set up an additional forwarding from port 80 (WAN), from port 443 and from port 1025, each to port 25565 (LAN). Let your remote friend verify that those ports work for them, then try again from school.

[UnholyDecimator]

When you try to connect from your school, does the server console show anything relevant?

Perhaps try forwarding an additional, different port than the default minecraft. Usually home NAT devices allow you to port-forward WAN port X to LAN port Y, where X is different to Y. Some ports will most likely be blocked by your ISP, but perhaps some will work. Try to set up an additional forwarding from port 80 (WAN), from port 443 and from port 1025, each to port 25565 (LAN). Let your remote friend verify that those ports work for them, then try again from school.

No the console never printed anything, revealing that it was never receiving the packet from my school. However, I managed to get myself a public domain, and then my school could now see the ip. This I find interesting, perhaps my school has a filter where it will only see servers hosted by a public domain.

I just checked it now from my school and it now connects correctly.