[SOLVED] Port Forwarding - Modem / Router not playing nice, or am I missing something?

Adam B

Honorable
Feb 18, 2014
34
0
10,530
Hello!

I'm trying to use my computer to host a centralized version control server for a team coding project, and so far everything is seemingly set up correctly in terms of the server, and the client sides -- except that the TCP connection fails due to an issue with my port 1666, which the software (Perforce Helix Core) uses. Despite all the settings you will see below, port 1666 remains closed. The port is currently not listening according to netstat, and port checkers also show it as closed, and of course, Perforce client gives a "TCP connection failure: check port" when trying to connect from another computer.

I will say, I am not the best router/modem configuring, but I have definitely set up port forwarding in the past and not had this much trouble. Unfortunately, I am currently stuck with a questionable router/modem combo -- Router: tp-link Archer C59 v2.0 // Modem: ARRIS TG02DCG1682NDTW, and I feel like they are not playing well together, or I'm missing something stupidly obvious. I even had a buddy in IT look at it very briefly, and he couldn't figure it out.

In the tp-link settings, I have these entries in Port Triggering AND Virtual Servers respectively. I have experimented with changing the protocol to 'ALL', even though I know it's TCP.

IPv4 --> 192.168.0.182

View: https://imgur.com/LyK2wYZ

View: https://imgur.com/MpIyBow

Within the ARRIS modem firewall settings:
My IT friend pointed at that it seems that even though the ARRIS model is in "Bridge" mode, it is not really behaving like it is in that state. Here are the settings I have set in the modem:

View: https://imgur.com/McnkvoB

View: https://imgur.com/0W6C5kd

Above: I have the modem port forwarding to the router, which is what I gathered I was meant to do from online tutorials. I have already attempted to point it directly to the server (192.168.0.182), and that definitely didn't work.

Note that although the protocol types say "both", even though I've explained that it is definitely TCP, rest assured that I have tested it either way with no change in result.


Am I just working with garbage hardware, with no recourse other than to upgrade, or am I missing something?

Thank you immensely for taking the time to read this far, and hopefully provide some useful tips. If any more screenshots or settings need to be shared, or commands run, etc, please advise me in a post as I will be checking periodically, ready to provide.

Adam
 
Last edited:
Solution
Yeah, this is reminiscent of why I went to a straight modem with my xfinity setup. I believe you can put the arris into a 'modem only' modem which should allow your tplink dmz to work correctly.
So the problem is that you have a double nat going on because the arris unit is also a router. What I would do is put the tplink router in the dmz of the arris so you don't have to worry about any port stuff on the arris and can handle it all on the tplink. That should fix the problem.
 
I have enabled DMZ on the ARRIS modem and added the router (192.168.0.1) to no avail. I have even tried temporarily disabling the firewall altogether, and adding the host PC to my router DMZ as well, just to humor it.

It's frustrating, because isn't the modem's 'Bridged' mode supposed to allow data pass through without routing? Because I am looking at it right now in my Arris modem. NAT Mode = Bridged.

Any other suggestions? I also do not know if this information is pertinent or not, but my computer is connected by ethernet to the TP-link.

Thank you for the help thus far!