Remove Ubuntu/Debian version from sshd server string

For security reasons, I don’t like that “Debian/Ubuntu” shows up on my sshd server string.

You can see the sshd server identification string by telnetting to port 22.


$ telnet ngmarley.com 22
Trying 106.187.97.211...
Connected to ngmarley.com.
Escape character is '^]'.
SSH-2.0-OpenSSH_6.0p1 Debian-3ubuntu1
^]
telnet> quit
Connection closed.

It’s very simple to just remove the “Debian…” part off the end.

Just edit /etc/ssh/sshd_config and append

DebianBanner no

to it.

Then re-start your sshd:


service ssh restart

… and now verify that it’s gone:


$ telnet ngmarley.com 22
Trying 106.187.97.211...
Connected to ngmarley.com.
Escape character is '^]'.
SSH-2.0-OpenSSH_6.0p1
^]
telnet> quit
Connection closed.