server Unable to log into server hosted on same computer

[Sparkplug1034]

I have 64-bit Java installed, I have Hamachi running (I used to use it all the time for vanilla servers), and I opened the launch.bat batch file. The server runs perfectly fine from what I can tell; I even scrubbed through all of the forge modloader text files in search for errors and such. When I add a server with my computer IPv4, with or without the server port extension, it is not detected. I even tried to host a vanilla (snapshot) server using Hamachi, and I have encountered the same problem, which leads me to believe it's a computer issue and not the server itself.

I've tried experimenting with every variable I could think of in the server.properties file, but to no avail.

 

Any suggestions, anyone?

 

I'm attempting to run the Attack of the B-Team 1.0.12a version server.

Also, disabling my computer's firewall and not using Hamachi is not an option.

 

Environment: Windows 8 (64 bit), Java 64 bit, decent internet, LogMeIn Hamachi, sugar, spice, and a dose or two of ignorance...

 

(I don't quite expect anybody to be able to tell me exactly what that issue at hand is, but suggestions of things to try is greatly appreciated. I am trying to get this server running for a buddy and I)

[disconsented]

Connect via "localhost" /127.0.0.1

[DanielUSA]

modem also have firewalls that you need to turn off. there is an option in your modem settings that is called "DMZ". I always turn it off because it causes issues when Peer 2 Peer connecting.

[Loader]

Direct connecting to 127.0.0.1 won't use the modem, internet or even network.

 

Minecraft doesn't use any form of Peer to Peer networking, it's pure client-server architecture (even in singleplayer it's connecting to an internal server on 127.0.0.1).

 

Because it's client-server you need some form of port forwarding for port 25565 across the internet - the DMZ is one way of doing that (it just passes all the port requests to a single IP), Hamachi is another way to do that (it's basically a series of DMZs pointed to the hamachi ip addresses if you want to look at it like that).

 

You won't be able to connect or ping your own internet (WAN) IP address or hamachi IP from your own computer, use the local loopback (127.0.0.1) for that.  You may be able to ping your own local IP (192.168.?.? probably) depending on how your network is configured.

 

If the firewall is blocking connections on 25565 and changing that isn't an option, then playing multiplayer isn't an option.  Turning the firewall off temporarily is a way to check to see if it's causing any problems - if it works fine with the firewall off then you need to make some changes to settings in it, if it doesn't make a difference then you can try turning it back on at the end when it's working and seeing if it makes a change then.  You're right in that it's a nice thing to have and keeping it on is more secure than not, but it's not much of a risk to have it off for a short period of time (and in all honesty if someone has the skill to take advantage of the firewall being off then it likely won't make a difference if you're using the standard windows firewall and they want to attack you for some reason).  The windows firewall is capable of blocking local loopback requests, so you can't rule it out just because it's running on the same machine.

[Sparkplug1034]

Direct connecting to 127.0.0.1 won't use the modem, internet or even network.

 

Minecraft doesn't use any form of Peer to Peer networking, it's pure client-server architecture (even in singleplayer it's connecting to an internal server on 127.0.0.1).

 

Because it's client-server you need some form of port forwarding for port 25565 across the internet - the DMZ is one way of doing that (it just passes all the port requests to a single IP), Hamachi is another way to do that (it's basically a series of DMZs pointed to the hamachi ip addresses if you want to look at it like that).

 

You won't be able to connect or ping your own internet (WAN) IP address or hamachi IP from your own computer, use the local loopback (127.0.0.1) for that.  You may be able to ping your own local IP (192.168.?.? probably) depending on how your network is configured.

 

If the firewall is blocking connections on 25565 and changing that isn't an option, then playing multiplayer isn't an option.  Turning the firewall off temporarily is a way to check to see if it's causing any problems - if it works fine with the firewall off then you need to make some changes to settings in it, if it doesn't make a difference then you can try turning it back on at the end when it's working and seeing if it makes a change then.  You're right in that it's a nice thing to have and keeping it on is more secure than not, but it's not much of a risk to have it off for a short period of time (and in all honesty if someone has the skill to take advantage of the firewall being off then it likely won't make a difference if you're using the standard windows firewall and they want to attack you for some reason).  The windows firewall is capable of blocking local loopback requests, so you can't rule it out just because it's running on the same machine.

This is extremely helpful. Thanks!  

I'll see what I can do. I always was able to log onto a Hamachi server that I hosted on my own computer (vanilla), when I used my old Windows XP dinosaur. Today I learned

[Loader]

XP has a security feature that Hamachi works around without telling you - it needs to install a special passthrough driver to allow connections to flow freely into and out of your network (Vista and on don't do this that way, Win2000 and back wouldn't have needed it).  It's not quite an exception because what's essentially happening there is Hamachi is acting as a proxy - all connections are going 'out' to the Hamachi adapter (outside what your computer sees as its internal network, but technically still on your computer) then coming back 'in', so it seems to be an acceptable request.

 

I wondered about mentioning proxies being the only exception and I figured "Nah, it'll just complicate things needlessly", of course you'd have encountered that exact situation that's caused confusion, just my luck.

 

EDIT: A proxy is just a machine that you pass your own requests to - so if you have a proxy at proxy.com (not a real thing), and you want to go to Google, you connect to the proxy and make the request.  The proxy actually does the request to Google (so Google sees the request coming from Proxy.com, not from you).  Once the proxy gets a response from Google, it sends it back to you.

 

 

In your situation Hamachi was the 'proxy', your other network cards are 'you'.  Because the proxy can access your computer from the outside (it's on the internet as far as your computer is concerned whether that's true or not), using the Hamachi local IP works fine.  This is an XP workaround as adapters aren't allowed to communicate with one another except in a few specific ways by default.

Edited June 29, 2014 by Loader

[DanielUSA]

What do you mean by "local host"/127.0.0.1

 

What is local host? An IP address?

 

Could you type an example out? I always have problems using LAN and this sounds like it might fix my issue.

[Loader]

You know how you connect to an ip address and it might be something like 192.168.1.10 for another computer on LAN?  Well, you can connect to 127.0.0.1 instead and it'll connect directly to your own computer (a 'local loopback').

The other way is to use the word localhost instead of a hostname (like mc.xeongaming.co.uk to take an example from the first result in the server section right now).

 

Both of these do the same thing, connect back to your own computer - if it's running the server then it'll just connect to it, no using hamachi/network/router/internet or anything because it's all running on the same computer and it doesn't need to.  It's for situations like the above where a player wants to use a client on the same machine that's running the server.