UNIX for Dummies Questions & Answers

Hopefully my question makes sense, but I was wondering if the telnet service has anything to do with console logins or if they are completely unrelated. So for example, does the /etc/default/login file in UNIX have anything to do with Telnet? So if I want to verify that the root user can't login in to Telnet (assuming Telnet is enabled), would it just be a matter of looking for the CONSOLE=/dev/console? And if the telnet service is disabled, would the CONSOLE=/dev/console even matter?

Thanks for any help you can provide!

What's your system?

Telnet is pretty archaic these days and often disabled or just never present in the first place.

I think what you mean is "how to allow root login only from console" is that so?
In which case, simple : add a line or create the /etc/securetty file if it does not exist containing only this line:

Code:

console

Various systems, but mainly Solaris 10 and RHEL. In almost all cases I've found that telnet was disabled but there were a couple instances where it was not. Also, I've found instances where it doesn't appear that root is restricted to the console (but root login via SSH is disabled) but telnet was disabled. Which brings me to the question of does it matter, if telnet is disabled could root still log in at the console?

Telnet is a network protocole... what is a console for you?

yes, essentially, though I was still wondering how it worked behind the scenes, depending on the various configurations.

so by adding "console" it restricts root to only console even if there are other lines in the file (e.g. vc/1, tty1, etc)? Also, this would be just for Linux, correct? UNIX would use the /etc/default/login?

thanks for the help.

Not quite... If you have only console in that file, root can only connect throught that...
But its not always true ( ever heard of xconsole?...).
This file lists valid consoles so whatever is found in that file, root can connect using it...
Older times ( I dont know if I can still remember how to create those devices....) you had e.g. in a class room a console on a teachers desk and many terminals (was my nightmare at the time...) all those were connected to a unix server via in many cases multiplexers tthat connected to the server using serial ports...