Problems Regarding Hamachi

inb4 infraction - May be in wrong place, but I figured Tech would be more proper since it also involved networking in a sense.

So my friend and I have had our own server to play LAN Games, MineCraft, Terarria, etc.

Up until today we had no issues, I would have him host and everything was fine. Though today, I was unable to connect to him at all. Not MineCraft, Terraria, and other games. But he could always connect to me, I just lagged a lot.

He tells me that he/his parents have not changed anything Net wise, nor him his side.

Any ideas?

 

Bumped.