My brother cant join my server

[gng45mil 0]

I made a server and everything works and i didnt get a single error since i made it.

But my brother can only join half the time.

It says connectoin failed after it is at a black screen that only says loading right after he clicks on my server in the server list.

the rest of the time he logs in perfectly without an error.

i dont change any settings or things like that.

I used the conans server files and this video to help me (theres two parts)

http://www.youtube.com/watch?v=ONFYu_ngsz8&feature=youtu.be

if you could help me thanks : )

[gng45mil 0]

heres the next part of the video

http://www.youtube.com/watch?v=mKUD8I70bRY&list=FLsVK5AeidlY9LSVokKgq5Ow&index=5&feature=plpp_video