SSH login using no-ip hostname or public IP denies my access

Question

I'm using PuTTy to connect to a home server I set with LinuxMint 15, open-ssh, all the necessary stuff.

I can login just fine with my user using the private IP like "[email protected]".

Then I installed no-ip Dynamic Update Client because I have a dynamic IP and I try to login with it like so: "[email protected]", the client connects but when I input the password, the server just refuses it. It does the same if I try to login using the public IP instead of the host name.

My assumption is that using that host name what I'm really doing is to connect to the router, could that be? My internet provider has a network where there are a couple of Access Points and everyone connects to them using WiMax antennas / routers (NanoStation M5) thus sharing the same IP, so it's not a simple network where my router is doing the NAT. In fact, in my situation there is a NAT in the access point where the NanoStation connects and another NAT in my Comtrend router that creates the Wi-Fi access point to my house... I hope the explanation is somewhat understandable.

So, my question is: What should I do to fix the login issue so I can connect to my home server using a domain name?

Solution

Unless you've configured some sort of 'port-forwarding' on the router's configuration, when you type the WAN address, your are actually attempting to log-in to another node that IS NOT your device.

Yes, the Dynamic Addressing service will redirect the hostname to your WAN IP - but unfortunately if you are sharing that WAN IP with other users, you are connecting to an unknown device.

For all you know, you are trying to login to a service provider device via SSH, that's why the password isn't working.

Comments

[jjlin]

Typically you'd have the access point port-forward to your router, and then have your router port-forward to your server.

[Zoredache]

What should I do to fix the login issue so I can connect to my home server using a domain name - Setup a tunnel/vpn between your home system and some system on the public? a HE IPv6 tunnel would work and is free. But the networks you connect from would also need to support IPv6.

[Deses]

I thought so... I guess I'll have to use a VPN as suggested by Zoredache.