Why can't I port forward?

[Ashiella]

A long time ago I used spectrum and their modem/router combo with 200/10mbps and port forwarded fine.
Then, I moved to a bigger city, got google fiber. I tried working with 2 different support teams at google to figure out why its not working, no one could figure it out. The google wifi router team kept saying its the ISP (google fiber) and the ISP kept saying it was the router. Moved again a year later, got spectrum so I could port forward, only other option is ATT... Some googling revealed that the modem/router combo unit aint the play for port forwarding, and also no $5/m charge so hey, i'll just get the free modem. Turns out I still cant port forward, for unknown reasons. Firewall is still set correctly, router settings correct, DHCP ip reservation set (not necessary but helped some people). Ports closed. I started looking up online why it may not be working, and besides saying its the spectrum router/modem combo unit, everything I saw suggested that it was likely the modems fault, being locked down and all (no accessible gui). I wasn't even able to use my Asus RT N66R router with the default spectrum modem, it always said ISP DHCP not setup correctly. I bought a new modem (netgear cm600), and the asus router finally worked, port forwarded with it, setup static ip, ports still closed. I tried doing text tech support with spectrum and they told me to call a number for "advanced tech support" I did, and then was met with 28 minutes of: It's the router, its nothing on spectrums end.
But with everything correctly configured on my end, changing ISP's, Routers, Modems, Pc's, and it STILL doesn't work, can anyone help?

[Biohazard777]

Just now, Ashiella said:

But with everything correctly configured on my end, changing ISP's, Routers, Modems, Pc's, and it STILL doesn't work, can anyone help?

Post screenshots of both the modem and router settings you've got now.

I personally find these kinds of situations far easier to solve when I have remote access. That being said never give access to people you don't know well... so if you've got a friend that could help you out that would be the logical next step if LTT forum and screenshots don't suffice.

[Windows7ge]

What have you done to test if a port is open?

 

If you have access to the spectrum router's WebUI and have configured everything correctly then you should be good to go. Common issues with port forwarding are Double NAT and people trapped behind NAT64-CGNAT but a Coax connected router network from Spectrum usually doesn't put people behind that. I have heard bad things about fiber networks though in that regard. Where you live may impact how this affects you. I'd verify that your public facing IP is in the Public Domain and not a NAT reserved IP.

 

You should also note that a online port checker will only tell you it's open if there's a server set on the port to reply. If the server isn't running and configured the port will still report as closed sending you down a rabbit hole.

 

In the worst of case you could configure a VPS and punch through that way. Just setup the VPS with VPN hosting software, connect and away you go.

[Ashiella]

13 hours ago, Biohazard777 said:

Post screenshots of both the modem and router settings you've got now.

I personally find these kinds of situations far easier to solve when I have remote access. That being said never give access to people you don't know well... so if you've got a friend that could help you out that would be the logical next step if LTT forum and screenshots don't suffice.

if you feel like remoting in, hmu in dm's.
 

 

 

[Ashiella]

13 hours ago, Windows7ge said:

What have you done to test if a port is open?

 

If you have access to the spectrum router's WebUI and have configured everything correctly then you should be good to go. Common issues with port forwarding are Double NAT and people trapped behind NAT64-CGNAT but a Coax connected router network from Spectrum usually doesn't put people behind that. I have heard bad things about fiber networks though in that regard. Where you live may impact how this affects you. I'd verify that your public facing IP is in the Public Domain and not a NAT reserved IP.

 

You should also note that a online port checker will only tell you it's open if there's a server set on the port to reply. If the server isn't running and configured the port will still report as closed sending you down a rabbit hole.

 

In the worst of case you could configure a VPS and punch through that way. Just setup the VPS with VPN hosting software, connect and away you go.

Mainly just portcheckers online, but also pings from friends via cmd.
idk how to see if its a public domain or nat reserved ip.
It does this whenever I host a server

and wdym about vps and vpn, I do have a friend willing to let me vpn into his network because port forwarding works for him, would this work?

[Lurick]

Spectrum doesn't do CG-NAT so you're good there.

You need to start the minecraft server on the local IP, it will then be port forwarded from your public IP to the internal IP. Right not it's trying to bind to your public IP address which you don't want.

[Ashiella]

2 hours ago, Lurick said:

Spectrum doesn't do CG-NAT so you're good there.

You need to start the minecraft server on the local IP, it will then be port forwarded from your public IP to the internal IP. Right not it's trying to bind to your public IP address which you don't want.

True, google did and they refused to acknowledge its existence.
I fixed that, mc server starts now. lol forgot I had to use the other ip. ports still closed.
side note, seems like my public ip keeps changing.. not sure how to change that either.

[Lurick]

Do you have a VPN currently enabled or a tunnel running? It looks like a PPP connection is up in the second right picture, that will cause your public IP to change

[Ashiella]

39 minutes ago, Lurick said:

Do you have a VPN currently enabled or a tunnel running? It looks like a PPP connection is up in the second right picture, that will cause your public IP to change

i did, and i turned it off (forgot i had it on from last night lol), i tested it again afterwards, and now it just works all of a sudden. i really didnt expect it to, but it works now, so, uh yeah.. thanks everyone for helping

[Windows7ge]

19 hours ago, Ashiella said:

and wdym about vps and vpn, I do have a friend willing to let me vpn into his network because port forwarding works for him, would this work?

I see you found the solution to your problem. That's good to hear.

 

In the scenario that CGNAT was the issue yes that could have worked but as Lurick had mentioned, I can also vouch that Spectrum doesn't normally use CG-NAT. At least in my experience.

 

If the system hosting the server is on a running VPN already then that explains a lot. You'll want that disabled or find another box to host the server independent from systems you want to run VPN's on.