Telnet problem

i_nomad · 03-27-2008, 05:38 AM

I am aware of the security issues but need to get it working.

#Telnet localhost gives the error

Telnet: Connection to address 127.0.0.1: connection refused
Telnet: Unaable to connect to remote host

I have Telnet installed

I try to start the service:
[root@linux]# service telnet start
telnet: unrecognized service

[root@linux]# chkconfig --list |grep telnet
> krb5-telnet: off

I have edited the file /etc/xinetd.d/telnet (there was not telnet file, so I created one and put entries in below)

# default: on
disabled = no

#/etc/rc.d/init.d/xinetd restart

After this the telnet service appears to run with description (xinetd is required for this service) and status (xinetd (pid6360 is running)

Not that it matters at this stage but there are no firewalls running.

I still cannot get telnet to work..any pointers?

Many thanks for your time

bathory · 03-27-2008, 05:57 AM

Your /etc/xinetd.d/krb5-telnet should look like this:

Code:

# default: off
# description: The kerberized telnet server accepts normal telnet sessions, \
#              but can also use Kerberos 5 authentication.
service telnet
{
        disable = yes
        flags           = REUSE
        socket_type     = stream        
        wait            = no
        user            = root
        server          = /usr/kerberos/sbin/telnetd
        log_on_failure  += USERID
}

After editing, restart xinetd and run:

Code:

chkconfig krb5-telnet on

samwise17 · 03-27-2008, 06:02 AM

There may be an example telnet entry in /etc/xinetd.conf that's commented out, if that file exists. Here is the telnet line from my Slackware install (Slackware uses ordinary inetd, but I think they're fairly similar)

Code:

# Telnet server:
#telnet	stream  tcp     nowait  root    /usr/sbin/tcpd	in.telnetd

If you're lucky, that file will exist and a similar line will be there. Just open the file in a text editor and remove the hash '#' from the beginning of the line:
[CODE]

If not, try adding that line to the file in /etc/xinetd.d/ you already created?

EDIT: Whoops, bathory beat me to it and seems to have a much better idea of what's going on. Listen to him :-)

i_nomad · 03-27-2008, 06:14 AM

The OS is RHES 4
I have looked at krb5-telnet. The file was identical to yours.
Restarted xinetd and ran chkconfig krb5-telnet on..same problem. However on inspection of krb5-telnet it sets back the default = no from the yes set.

Regards

bathory · 03-27-2008, 06:30 AM

Running "chkconfig krb5-telnet on" should change the disable = yes to disable = no.
The line that contains "default" is just a comment to remind you that by default telnet is off.
What is the output of:

Code:

 netstat -ta|grep telnet

i_nomad · 03-27-2008, 06:45 AM

#netstat -ta|grep telnet gives no output
#service telnet status gives telnet:unrecognised service
graphical output in services shows telnet running as descibed linked to xinetd.
I did previously try removing telnet RPM and reinstalling...same problems

Regards

bathory · 03-27-2008, 07:07 AM

Take a look at /var/log/messages to see if you find any errors. You can also run xinetd with the -d option (debug mode) to produce more detailed logs.

i_nomad · 03-27-2008, 07:52 AM

/var/log/messages:
Mar 27 11:38:39 mail xinetd[4472]: xinetd Version 2.3.13 started with libwrap loadavg options compiled in.
Mar 27 11:38:39 mail xinetd[4472]: Started working: 0 available services
Mar 27 11:38:58 mail xinetd[4472]: Starting reconfiguration
Mar 27 11:38:58 mail xinetd: xinetd -HUP succeeded
Mar 27 11:38:58 mail xinetd[4472]: incomplete entry [file=/etc/xinetd.d/krb5-telnet] [line=12]
Mar 27 11:38:58 mail xinetd[4472]: missing } in last service entry [file=/etc/xinetd.d/krb5-telnet] [line=12]
Mar 27 11:38:58 mail xinetd[4472]: missing service keyword [file=/etc/xinetd.d/telnetd] [line=2]
Mar 27 11:38:58 mail xinetd[4472]: missing } in last service entry [file=/etc/xinetd.d/telnetd] [line=2]
Mar 27 11:38:58 mail xinetd[4472]: Swapping defaults
Mar 27 11:38:58 mail xinetd[4472]: Reconfigured: new=0 old=0 dropped=0 (services)

xinetd -d:

08/3/27@12:51:06: DEBUG: 4597 {handle_includedir} Reading included configuration file: /etc/xinetd.d/time-udp [file=/etc/xinetd.d/time-udp] [line=17]
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing chargen
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing chargen
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing printer
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing daytime
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing daytime
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing echo
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing echo
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing eklogin
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing ftp
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing klogin
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing kshell
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing ntalk
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing rsync
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing time
08/3/27@12:51:06: DEBUG: 4597 {remove_disabled_services} removing time
Service defaults
Instances = 60
CPS = max conn:25 wait:30
Bind = All addresses.
Only from: All sites
No access: No blocked sites
Logging to syslog. Facility = authpriv, level = info
Log_on_success flags = HOST PID
Log_on_failure flags = HOST

08/3/27@12:51:06: DEBUG: 4597 {cnf_start_services} mask_max = 0, services_started = 0
08/3/27@12:51:06: CRITICAL: 4597 {init_services} no services. Exiting...

bathory · 03-27-2008, 08:11 AM

You should look better at /etc/xinetd.d/krb5-telnet for errors. Perhaps you miss the last "}"
You can copy/paste the one I've posted (it's from a RH AS3 btw) to see if it works.

Regards

i_nomad · 03-27-2008, 08:35 AM

You hit the nail on the head!
The end } was missing. I am quite sure I did not touch this file..
Anyway many thanks for your time...
;-)

bathory · 03-27-2008, 08:49 AM

Glad to see you've made it.

Regards