Port Forwarding on a Router Behind a Router/Modem without Port Forwarding

zebrajr

Honorable
Apr 26, 2014
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0
10,520
Hello,

So, where to start?
Guetting that out of the way first, I*m not new to Port Forwarding, NoIP/DynDNS / Opening Ports / DZM / etc, since I've done it on my previous home (Portugal).

Ok, now onto the issue:
I currrently live in Germany, my ISP is KabelBW (UnityMedia) and I'm using the modem that came with my package (120 Mb DSL).

Since I've recently acquired a RaspberryPi B, and a Raspberry Pi Zero is on it's way, I've thought about getting my NoIP back to work so I can VPN to my homenetwork on the run.
Since my Modem/Router provided by my ISP doesn't support Port Forwarding (or DMZ, or Static IP, or any useful configuration for that matter) I've brought a cheap TP-Link which has all this features and the, nowdays standard, Bandwidth QoS, etc, etc.

Port Forwarding in the TP-Link is done, same with static IPs, Bandwidth QoS, Ports are opened, serving the NoIP (working), etc, etc, etc.

So the issue is, my NoIP is updated though my TP-Link but any inbound connection is refused (even Ping).

I've tested with this guide to cascade a router but that didn't help.

So I was wondering if someone has any possible solution or workaround for me to be able to get an external connection going though the KabelBW modem/router into the TP-Link, since the TP-Link has every configuration needed to deal with everything else.

Here are some screenshots of the only configurations available on the KabelBW Modem / Router.

Notes:
Wireless is off since I'm being served by the TP-Link
Starting IP Address for the DHCP is starting at 192.168.0.3 because the TP-Link as the IP of 192.168.0.2 (KabelBW, 192.168.0.1)
Modem/Router from ISP can't even be set in Bridge Mode for that matter.

Thank you all in advance for helping,
Sincerely,
Carlos

tl;dr: Router behind a Modem/Router with almost 0 Configurations, looking for help to Port Forward / External Access to the Network or if the only solution is finding a better Modem/Router compatible with the ISP
 
Solution
The easiest option would be to call your ISP and request them to change the router they've provided you into bridge mode. Otherwise you could port forward using the dynamic port range, since those are always open.

For example in your TP-Link you would have to configure that the internal port for SSH is 22, but the external one 27300 (or any other high range really), and finally make sure that whichever software is going to connect from the outside to your pc via SSH is going to point to port 27300 instead of 22. There is also the chance of having conflicting ports, so this task might get very messy. Hopefully you'll be able to get your ISP to change the router into bridge mode.
The easiest option would be to call your ISP and request them to change the router they've provided you into bridge mode. Otherwise you could port forward using the dynamic port range, since those are always open.

For example in your TP-Link you would have to configure that the internal port for SSH is 22, but the external one 27300 (or any other high range really), and finally make sure that whichever software is going to connect from the outside to your pc via SSH is going to point to port 27300 instead of 22. There is also the chance of having conflicting ports, so this task might get very messy. Hopefully you'll be able to get your ISP to change the router into bridge mode.
 
Solution