Then you need to restart the SSH daemon. On many systems you can do that
by using this:
Server $ sudo service sshd restart
You might also want to change the default port from 22 to some other number.
Since everyone knows that port 22 is SSH, attackers will bombard your
server with attacks on that port. You should be safe by turning off root login
and passwords, so that you have to have a public key to log on, but if you
want to move to a different port to avoid any attacks, here's what you do.
In that same config file ( /etc/ssh/sshd_config ), add or change this line:
But pick a number other than 2345. You want a number greater than 1024,
and preferably a number that does not appear in the file /etc/services . Those
are numbers that other services might already be using (including 80 for web
When using ssh to connect to the server, you'll have to specify the new port
number, which you can do with the -p option:
$ ssh -p 2345 firstname.lastname@example.org
Your Linux distribution may come with everything you need. Or it might be
missing a few parts. To help keep things manageable, Linux breaks up all
the utilities and programs into different software packages . For example, if
you're not doing any work with publishing, you won't need TeX or Ghostscript.
If you're not programming in C or C++, you won't need GCC. If you're not on
a desktop machine, you probably don't need a window manager like Gnome
All of these packages of software can be installed, removed, updated, and
listed using a package manager. Every major Linux distribution uses a differ-
ent package manager. In fact, you could almost say the package manager is
what distinguishes one distribution from another, although there is some
sharing going on.
Popular package manager commands include yum , rpm , apt-get , and deb .
The details for each of these commands are different, but they all basically
do the same thing: download and install a software package for you.