Failing to SSH to my Ubuntu Server through a VPN router

Question

I've set up my Ubuntu server today, and can connect to it via SSH, although only from the same network. I've set up port forwarding on port 22 in my router settings, but still can't connect to it from outside my own network.

Btw: Astrill VPN is running on my routers.

Any help would be greatly appreciated.

Answer 1

Possible causes:

VPN

You will need to find out whether the network where SSH-ing works uses a VPN that other networks do not. If so, apply changes accordingly.

SSH keys

You will need to find out whether the SSH client you use outside the network is allowed inside the network. It is possible that knowingly or unkowingly you use a different SSH key when it works from the case when it is not working

Network settings

You need to find out whether the IP address can be found at all from the outside, do a

ping <someip>

to see whether the IP address is seen at all. If not, then check network settings at the tartget network and make sure that it supports requesting. Also, make sure that it allows ssh connections from the outside and make sure that the machine where you want to connect can be reachable from the outside.

Your IP address

It is also possible that your IP address is on a blacklist for some reason, check whether that's the case.