SSH over internet. Connection time out

Question

This question seems to come up a lot, but none of the answers seem to work for me. I'm trying to connect to my RPi over the internet, but when I try to connect over the internet (with putty) using a dynamic dns it get a Network error: Connection timed out.

I've done the following steps:

1. I assigned a static IP to my RPi. I tested this with a reboot of both my router and my pi and checked with ifconfig each time. I can SSH through my LAN just fine so the issue is definitely not here.

2. I created a hostname on no-ip and setup a script to update the hostname when it changes. The hostname's IP corresponds with my router's IP. I'm not sure if the auto-update works but that's another issue.

3. I setup a port forward from my router (source port 22322) to my RPi's static IP (destination port 22). I used http://canyouseeme.org/ to confirm if the port's open and it says it's successfull.

4. I added a rule to iptables to allow the traffic, iptables -L returns the following:

   root@foxypi:/home/pi# iptables -L
   Chain INPUT (policy ACCEPT)
   target     prot opt source               destination
   ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:ssh
   
   Chain FORWARD (policy ACCEPT)
   target     prot opt source               destination
   
   Chain OUTPUT (policy ACCEPT)
   target     prot opt source               destination
   

5. In /etc/sysctl.conf I uncommented the line net.ipv4.ip_forward=1

From what I've read this should allow me to SSH into my RPi, but it just won't work and I'm stumped. Did I miss a crucial step?

Answer 1

Apparently I made an incredibly simple oversight. Turns out my router doesn't support NAT loopback so when I tried to connect over internet while I'm on the LAN network it didn't work. I just tried again from a public wifi and it works without a hitch.

For those who have the same issue, try connecting from a machine that's not connected on the same LAN as the RPi.