Solved Block lag

[PappleFruit]

Hello FTB Community!
So, my cousin are playing on an FTB Monster server (1.1.1 with GraviSuite mod) that I am hosting. We use LogMeIn Hamachi. I can play without any problems or lag and I have a decent FPS rate (almost always more than 80 FPS). However, my cousin has a massive block lag whenever he joins the game or enters a new dimension. It also happens when he walks a few blocks (10-20) horizontally. After around one minute, everything is okay again, however entities are always lagging.

These are our PC-specs (we both have almost the same):

-Intel Core i7 3770k @3.50GHz
-Palit GeForce GTX 670 (I have the normal one, my cousin has the Jetstream version)
- 16 GB RAM (Mine: 2x8 GB DDR3 Corsair Dominator; cousin's: 4x4 GB DDR3)
- Samsung 840 Pro 128 GB SSD (cousin: 830 Pro)

My internet connection:

50 MBit/s Download
2.5 MBit/s Upload

My cousin's internet connection:

100 MBit/s Download
5 MBit/s Upload

My router (and his):

AVM FRITZ!Box 6360

If you need more information, I will update this post.
I hope, you can help us.

 

[Connor Gavitt]

Just to be clear your server is hosted on your computer, and your cousin is on the same network or is he local, also why are you using hamachi instead of port forwarding?

 

[PappleFruit]

Just to be clear your server is hosted on your computer, and your cousin is on the same network or is he local, also why are you using hamachi instead of port forwarding?

Yes, the server is hosted on my computer and he is not on the same network, he lives further away. That's why we are using Hamachi. We have tried port forwarding but it didn't work in both networks and we don't know what we did wrong. (We opened the port in both the router and the firewall (TCP and UDP)) So then we decided to go with Hamachi instead to save time searching for the mistake.

 

[PappleFruit]

So apperently my internet provider only provides me with IPv6 adresses, which makes port forwarding for IPv4 adresses impossible. But when I try to join an IPv6 server, I get the following exception:

java.net.socketException: Protocol family unavailable

What can I do about that?

PS: My cousin has the same internet provider.

 

[PappleFruit]

So apperently my internet provider only provides me with IPv6 adresses, which makes port forwarding for IPv4 adresses impossible. But when I try to join an IPv6 server, I get the following exception:

java.net.socketException: Protocol family unavailable

What can I do about that?

PS: My cousin has the same internet provider.

Okay, so I figured that one out - I had to go to the Advanced Options in the FTB launcher and had to insert the following additional Java parameters:

-Djava.net.preferIPv4Stack=false -Djava.net.preferIPv6Addresses=true

Now, the next prolem I have is that I don't know how to forward the IPv6 ports properly. Can anyone help me with that? I used the ipconfig command and there was an IP that I can use to join my server but port forwarding doesn't seem to work with that IP - I used an IPv6 port checker and it told me, that the connection was refused...

 

[PappleFruit]

Okay, I figured it out myself, I already had the problem solved but the IPv6 port Scanner wasn't working properly. The thread may now be closed.