I am unable to login via telnet to my Linux server (running YellowDogLinux) using the root account. But I am able to do so with an ordinary account. Why is that?

When I'm logged in as an ordinary user, I could change to SU with the same root password with no problem.

Another thing I noticed was I can't run certain commands after I logged in, not even after I switched to SU. For example when I run ifconfig, it tells me command not found. On the server itself i have no problem executing this command.

Thanks for your insight.

possibly because telnet is insecure & the developers @ ydl have disabled root login so as to offer some protection for people who still need to use telnet.

try su-

& c what happens.

Thanks. Trying su- works. Just out of curiousity, what does that little "-" do?

Also, out of curiosity, can anyone tell me where do we enable or disable root login for telnet?

as far as i know, you can't and you shouldn't anyways. it is setup that way for security purposes... if you want a secure login thru telnet though, i would recommend checking into ssh.

the reason you don't want to login directly as root is cause if anyone was to get your root password, then they have full control of your machine...

The "-" logs you on as root rather then just makes you root, i.e. you get all the log on scripts running.

You still shouldn't send your root password over telnet though! Use ssh, its a lot more secure, has lots more features, and windows clients are available.

First I don't recommend you using an insecure protocol like DARPA "i.e telnet", use SSH2 instead for remote access.
And never allow root access as brute force on telnet is quite fast.

anyway answering your question, you need to allow access to the terminal that telnet uses for root, to do this you would add the lines.

ttyp0
ttyp1
ttyp2
ttyp3

to the file /etc/securetty

Type "man securetty" to find out more about it.

as Dorward already said the "-" option tells login to run the users environmental setting scripts from its home directory.
Can also use "-l"
eg. su -l root

/Raz

Any how telnet root login possible in FC2/centos 5 i386(not considering security issues).
For me it works in FC2/centos 5 i386 after executing this command:
mv /etc/securetty /etc/securetty.save(if other local user loggin is possible through telnet).
Try again root login through telnet after this with root password correctly

I think a 7 year old zombie post must be a record!!!

Did you notice when this thread was last updated?

takuttamkumar, don't resurrect dead threads. Closed.