How to set up ssh connection (acessible over internet, not LAN) using MTS MBLaze modem?

Question

I have a MTS MBlaze USB dongle, with which I can connect to the internet. The question is, how do I set up a ssh connection accessible over the internet so that any one can connect to my PC through that (using valid username/password provided by me of course) ? If not possible, what do I need to make this possible ?

I'm using ubuntu 10.04 - but can upgrade if absolutely required.

Solution

install ssh

First things first. You need ssh installed. Not just the client, the server too. Find out:

$ which ssh
/usr/bin/ssh
$ which sshd
/usr/sbin/sshd

If which can't find them, you need to install: sudo apt-get install ssh sshd.

The install process should set up everything, but just in case, make sure the ssh port (22), is open (if ufw is disabled, consider enabling it): sudo ufw allow 22/tcp

what is your address

Type ip addr | grep inet to get your ip address. If it starts with 192.168., 172.16. up to 172.31., or 10., you have a local (aka private) ip address. Otherwise it is public (eg 74.125.224.51). If it is public, you have it easy. Anyone can try and connect with a command like ssh [email protected].

If you are stuck with a local IP address, you need to configure your router to forward port 22 to your computer. Then you can go to a site like http://whatismyip.org/ to get your public ip address, and anyone who has it can try and connect with a command like ssh [email protected].

get a permanent address

Sign up with http://dyndns.com/ for their free Host Services to link a dyndns name to your ip address. I'm assuming here that you have not bought a static ip address from your ISP.

Comments

[TCSGrad]

Pretty much nailed it :)

[nanofarad]

Is openssh-server significantly different from sshd?

[djeikyb]

@hexafraction openssh-server provides an implementation of sshd. it's well-respected, to say the least.

[cosmicraga]

"If you are stuck with a local IP address, you need to configure your router to forward port 22 to your computer". How to perform the port forwarding ?

[djeikyb]

@cosmicraga very much depends on your router. if yours is a popular model, you may be able to ask a question on one of these StackExchange sites