[SOLVED] Unable to connect two computers on different networks, works on same

[miatlas91]

Hi all,

So I'm trying to netplay with a friend in a different city using an emulator. The two emulators we've tried using to connect to one another are Kega Fusion and Zsnes. So far, we've been unsuccessful.

I'm aware of port forwarding and setting up a Static IP. For the sake of practicality in testing, I'm attempting to connect my Acer notebook to my Dell XPS, both of which are on the same network - my wireless connection which I use to connect to the internet. I've designated the Dell as the host and the Acer as the client.

Here's the thing: the applications connect successfully in both emulators when I try to connect the Acer to the DELL, as long as both are in the same network. However, if I disconnect the Acer from the wireless service of my modem/router, and instead connect the Acer to my phone's mobile data and mobile hotspot, it fails to connect. I've ensured firewalls are disabled for the emulators on both devices, and since they connect when they're on the same network, I assume firewall issues can be ruled out.

This leaves port-forwarding and using a static IP. I've been able to setup a static IP: in IpV4 properties under the control panel, I've used the "Use the following:" option (not "Obtain automatically) and set the IP as the same one as my private IP except added 10 to the last two digits (0.12 originally, 0.22 as static), as well us setup the DNS numbers, subnet mask etc. I assume the setup is correct because I'm able to connect to the internet with the static IP.

In Kega Fusion, if I supply the Acer the 0.22 IP and use that to connect to the Dell, it again connects successfully but only if the Acer is again on the same network as the Dell. If I test it with the mobile hotspot, it doesn't connect.

I have attempted to port forward and ensured the correct ports are selected, with UDP/TCP selected, and the Static IP entered as the IP to forward. However, I'm still not able to connect. I have a public IP as well which I'm not sure if it will come into play somehow.

Based on the above, would it be possible to provide some solutions? Its strange for it to work normally on the same network, but not work when its on the phone's internet network (i.e. two different networks). Please note that even with the above things done, I've tested again with my friend and it still doesn't work, so I'm fairly certain there's no difference between using a phone's internet network and a standard ISP-provided service.

My modem/router is a SmartRG 804n and OS is Windows 7. Thanks in advance for any guidance, and apologies if I come off as misinformed. Just trying solutions based on what I've researched.

 

[bill001g]

Port forwarding rules are confusing in many routers. Try the DMZ option since you only have to get the IP address correct. You do not want this a long term solution but then you know it is just figuring out the port forward rules

Be very sure you have a public IP it has been extremely common for people to ask similar questions to yours here. You need to be sure the IP you see in the WAN settings on your router matches sites like whatsmyip.

Lastly it may depends on the application. Does the session always go say A---> B . This assumes A is on the outside and B is your machine on the LAN. If the application would attempt to open a session back the other direction then you would need port forwarding working in both directions. This will likely never work on phone network because they do not have public IP. It should work to another persons house but it would depend on both port forwarding being setup. This all depends on the application, I do know those 2 programs, the more common game servers do not open a reverse session.

 

[miatlas91]

Thanks for the reply bill001g.

I will try the DMZ option, and ask my friend to do the same just in case. I assume a static IP will be appropriate here. If it works, I'll keep in mind that it's not a long term solution, and that port-forwarding is still where the issue lies. In the router's residential gateway config, setup page, the WAN IP address indeed shows the same public address as the one I see from whatismyip. So surely no issues on that end.

I can't tell if either application is opening a reverse session, but I don't think such behavior is actually happening. In both Zsnes and Kega Fusion, the only available options are hosting and joining. So one is host, and the other is client. There wasn't any mention of reverse sessions with respect to netplay for either applications' netplay guides I've come across thus far. Regardless, I'll have my friend check his port-forward setup as well before testing again.

And I'll surely stop doing any further testing with using the phone internet.

There's already some useful info here to help narrow things down. If we manage to get this working, I'll post what we did.

Thanks again!

 

[miatlas91]

Thought I'd post an update.

The problem has been resolved. DMZ host option worked, but port forwarding still did not. Turns out I needed to NOT use my public IP in the External IP address box in the router's port forwarding page. It should simply be left as 0.0.0.0 (which is the default any way). Additionally, though obvious in hindsight, the client should have been using the host's public IP in the application's join option to connect, not the host's private IP (which would instead be used if both client and host were in the same network). All works well without the need to enable DMZ host option.

Also, using my phone's mobile hotspot tethering for the client to connect to the host worked as well, so it appears there is some leeway there for testing public connectivity between devices.

I also found this place to be useful: http://www.pcwintech.com/common-problems-fixes-port-forwarding#:~:text=DMZ is a open all,make sure DMZ is disabled.

The port tester tool there was useful in determining whether the port was open or not.

Hope this info will be of use to others.