Not as lucky here with switching to modem then back to battle.net.

Question. Did you select a character? I tired a few variations with selecting a character and not selecting one but no luck. Heres hoping they look into this issue!

Thanks for the method though. Its cool to see us fans trying to find a work around. Maybe other folks will have better luck.

Doesnt work for me too.

I have to correct my statement.

Switching "modem-battlenet" works on the computer at work and at a friend but on my home computer the problem still occurs.

Damn.

Hi,I have the same problem, I have not tried using this "weird" method yet, but I am going to try when I be in my homes.

Your Internet connection is either very poor or is not processing UDP packets through port 6112. You will be able to chat but will not be able to play games.
Contact your Internet service provider or your system administrator for assistance with opening this port.
Ugly message =(

i did not select any char, just went into IPX or Modem mode then cancel out. have to do this every time though to get rid of the red warning sign and to be able to create/join games.

funny thing is i did not even portfoward any ports on the router, and suddenly this method worked. i did reinstall the game once.

I forwarded the ports and now I can't even connect to battle.net lol

I have done everything other people have done, I did the port forwarding, I did the inbound/outbound 6112, I rebooted, updated, wrote my congressman, called my mom, prayed to satan...nothing is working. It's ridiculous. And of course Blizzard doesn't have any customer support on this and GOG is saying B-net is a Blizzard issue. So I'm stuck in a digital bureaucratic nightmare and all I want to do is eat sour patch kids and relive my gaming days from middle school.

If ANYONE is having this issue and they find a fix, I IMPLORE you; take the time to post here and describe what you did, step by step (day by day) If you work for GOG and are reading this, I IMPLORE you to update this thread if you push an update. Don't leave us in the proverbial wind. I love you. Goodnight and good luck.

Port forwarding is only useful for people who have direct access to internet from their router, in other words, this (simplified) connection schema:
Internet -> your router -> your PC

If you have any other networking setup than the one described above, port forwarding WON'T HELP. Many ISPs provide internet based on this (again, simplified) schema instead:
Internet -> ISP's router -> your router -> your PC

By setting up port forwarding, you configure your router, but you don't configure your ISP's router. So the connection on 6112 port incoming from the Battle.net smashes into the brick wall called ISP's router, and will never reach your router.

I recommend downloading Hamachi and finding others to play with via the forum here.

What about the other ports and getting the error message -> going back -> going in again?
v see here

This right here is spot on. So for everyone saying they fixed it by clicking on random things in the menu didn't really fix it. That isn't the work the protocol works.

As Realpsojed port forwarding isn't a real solution either for most people. For example I have a dedicated internet line. Basically I'm what my own ISP since I'm using Ethernet over copper internet connection since where I live had no internet prior to me doing this. So I don't have a modem, just a nighthawk router with a custom ip and dns setup by the provider. Even so port forwarding would do me no good in this situation.

If you are in here and have disabled your windows firewall, or added custom rules on both firewalls, hardware/router and port forwarding etc.. done everything including take out the trash and wash dishes and you still can't connect than your options are to contact your isp and tell them GOG/Blizzard are using ancient technology and you need them to open the port. Or you can do like he said above and use Hamachi otherwise enjoy your 10 dollars in single player mode (or you could have a lan party)

There is a solution: get a vpn with port forwarding.

did you run diablo as admin?

No, all you have to do is get a vpn on the internet that provides port forwarding services and open the windows firewall ports 6112 to 6119 TCP and UDP.

Will the vpn also help if you can't host due to people getting high latency error?

Im not able to do port forwarding or mess with my router,any other way? I get the port error