topic Re: Weird Telnet problem in Operating System - HP-UX

Weird Telnet problem

shasha_1 — Tue, 19 Jul 2005 23:59:34 GMT

I am trying to login to my two Itanium servers using telnet but it seems that the telnet command doesn't accept my password. I have tried logging in using ssh, Xterminal and rlogin and even tried ftp using the same password and they all worked. I just changed the root password because for strange reasons, I was not able to access the servers using the root account. But now, I cannot use telnet anymore. I have already checked /etc/services and inetd.conf and there's an entry there about telnet. And I don't get a "Connection refused" error, I just think that telnet doesn't accept the password I type. I have tried changing the root password a number of times already but still can't login.

Re: Weird Telnet problem

Duncan Edmonstone — Wed, 20 Jul 2005 00:05:12 GMT

Donna,

WHat's the entry for telnet in /etc/inetd.conf look like?

Duncan

Re: Weird Telnet problem

Gopi Sekar — Wed, 20 Jul 2005 00:05:13 GMT

check /etc/securetty this file lists the tty sessions which are allowed for root login. by default these point only to tty1 to tty12 you may have to add /dev/pts/1, /dev/pts/2 entries in order to get it work

Regards,
Gopi

Re: Weird Telnet problem

Mel Burslan — Wed, 20 Jul 2005 00:05:48 GMT

do you have a file called /etc/securetty on your system with word "console" in it ? If so, root can only login from console directly, no other places will allow direct root login. Try logging in as a regular user and run "su -" command to obtain root privileges.

if your system is trusted and you have exceeded your login retries, you may have to go to the console to unlock root account as well.

hope this helps

Re: Weird Telnet problem

shasha_1 — Wed, 20 Jul 2005 00:16:31 GMT

Inetd.conf entry is this:
=================================
telnet stream tcp6 nowait root /usr/lbin/telnetd telnetd

================================

I tried searching for the /etc/securetty file on both servers but it is not existing.

Re: Weird Telnet problem

Mel Burslan — Wed, 20 Jul 2005 00:26:16 GMT

can you login as a regular user and then run su - command to get rood privileges with the password failing over your telnet session ?

Also, for ssh and telnet are you using the same terminal emulator ? even if they are the same, are you sure their keyboard mapping profiles are the same for both telnet and ssh ? I have seen strange things happen when keyboard or terminal type set incorrectly. Better check early in the game than later.

Re: Weird Telnet problem

shasha_1 — Wed, 20 Jul 2005 01:05:32 GMT

Yes I can login as a regular user and can run su - root successfully.

I am using terminal type HP for both ssh and telnet but only ssh is working. I have checked the keyboard mapping and it is the same.

Re: Weird Telnet problem

Duncan Edmonstone — Wed, 20 Jul 2005 01:46:15 GMT

Donna,

Probably unconnected, but I never trust the IPv6 implementation on 11.23, so I'd take it out of the equation by changing the line in /etc/inetd.conf. simply replace 'tcp6' with just 'tcp' and then run 'inetd -c' to reload the configuration.

I don't think this is the problem though, as I would expect it to effect other users as well as root.

You could also turn on inetd logging by running inetd -l. Then see if you get any useful messages in the syslog.

HTH

Duncan

Re: Weird Telnet problem

shasha_1 — Wed, 20 Jul 2005 02:29:23 GMT

Hi,

Turned on inetd logging and this is what I saw in syslog:

Jul 20 14:23:32 wbscsp02 sshd[12768]: Accepted keyboard-interactive/pam for root
from 10.10.21.164 port 3703 ssh2
Jul 20 14:24:12 wbscsp02 inetd[933]: Connection logging enabled
Jul 20 14:24:24 wbscsp02 inetd[12801]: registrar/tcp: Connection from wbscsp02 (
10.10.5.10) at Wed Jul 20 14:24:24 2005
Jul 20 14:24:43 wbscsp02 inetd[12802]: telnet/tcp: Connection from unknown (10.1
0.21.164) at Wed Jul 20 14:24:43 2005
Jul 20 14:25:03 wbscsp02 sshd[12804]: Accepted keyboard-interactive/pam for root
from 10.10.21.164 port 3725 ssh2

What do you make of this?

Re: Weird Telnet problem

Duncan Edmonstone — Wed, 20 Jul 2005 02:57:27 GMT

Nothing strange in syslog... lets be clear what happens:

- you telnet from another host and get a login prompt, enetr root and hit return, enter the password and it return... then what happens? does it just disconnect or do you get any message at all?

Lets make sure that telnetd isn't something it shouldn't be also... what's the output of 'what /usr/lbin/telnetd'

HTH

Duncan

Re: Weird Telnet problem

shasha_1 — Wed, 20 Jul 2005 03:26:30 GMT

Output of what...command

/usr/lbin/telnetd:
Copyright (c) 1983, 1986 Regents of the University of California.
$Revision: B11.23.0409LR

Everytime I try logging in, I am prompted for the user name, enter root and then hit enter. After that, I am asked for the password, I key-in the password and hit enter. After that, I am again prompted for the login, no error whatsoever.

Re: Weird Telnet problem

Duncan Edmonstone — Wed, 20 Jul 2005 03:46:15 GMT

Hmmm - Are you seeing bad login attempts logged to /var/adm/btmp ? Check by running 'lastb -R'

Is this a trusted system?

What are the contents of /etc/default/security ?

Does the shell listed for root in /etc/passwd exist? Does the home directory listed for root in /etc/passwd exist?

HTH

Duncan

Re: Weird Telnet problem

Dmitry G. Spitsyn — Thu, 21 Jul 2005 00:16:03 GMT

Hi Donna !

Please look into the following files:

/etc/pam.conf
/etc/pam_user.conf (if applicable)

Also please check:

what /usr/bin/login

May be there is some problem with patches on your suystem.

BR,
Dmitry.

Re: Weird Telnet problem

Ermin Borovac — Thu, 21 Jul 2005 00:29:34 GMT

Does your password contain "#" or "@" characters? These characters have special meaning to the terminal driver.

# stty -a < /dev/ttyconf
min = 4; time = 0;
intr = DEL; quit = ^\; erase = #; kill = @
eof = ^D; eol = ^@; eol2 ; swtch
stop = ^S; start = ^Q; susp ; dsusp
werase ; lnext

To fix you can either exclude "#" and "@" from your password OR run the following command

# stty kill '^X' intr '^C' erase '^W' < /dev/ttyconf

These settings are not preserved across reboots so they will need to be placed in a startup script.

Re: Weird Telnet problem

zhi wang_1 — Thu, 21 Jul 2005 07:56:39 GMT

Donna,
You said you tried ssh and it worked. As far as I recall, to enable ssh you will have to "disable" telnet. After you comment out telnet you must run inetd -c to recompile the inetd.conf file. Similarly you will have to run it again if you "enabled" telnet for inetd.conf to take effect. Try it and hope that is what causing the problem.

Re: Weird Telnet problem

shasha_1 — Sat, 23 Jul 2005 04:56:50 GMT

Hi,

I changed the password and removed the @ then tried telnet. It's now working.

Thanks all for the help.