How do I implement Secure Socket Shell (SSH)? Through a firewall? Client required? On Unix? NT?
There are two pieces to SSH. One is the SSH server and the other
is the SSH Client. For most versions of Unix, you can get SSH
server software and installation instructions from http://www.openssh.org
For Windows NT, I don't know of any open-source version. Commercial
versions are available from http://www.ssh.com
. There may also be
others. Note that these are commercial products, so I'm sure they can
assist with installation.
For the client side, there are many choices and http://www.openssh.org
has links to where you can find them. Installation of the clients is
for each, and you'll have to look at the instructions that come with each
The commercial firms noted above also have client software.
I use SSH through a firewall with no problem. Obviously, the firewall must
allow the connection. The firewall I pass through allows most everything
and allows anything in that was requested by a host inside the firewall.
It uses what is known as "statefull inspection" to track this. (Please see
an earlier question I answered about firewalls for more info on statefull
I doubt you'll have much problem getting through a firewall. If you do,
explain to your firewall security admin what you are trying to accomplish, that is provide more security than plaintext telnet, and they'll likely work with you.
This was first published in June 2001