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Bug 244022

Summary:	Temporary failure in name resolution: Illegal seek when telneting to RH5
Product:	Red Hat Enterprise Linux 5	Reporter:	Kenneth Hansen <khn>
Component:	telnet	Assignee:	Adam Tkac <atkac>
Status:	CLOSED DUPLICATE	QA Contact:
Severity:	medium	Docs Contact:
Priority:	low
Version:	5.0	CC:	ovasik
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2007-09-03 08:49:39 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Kenneth Hansen 2007-06-13 12:50:26 UTC

Description of problem:
When trying to telnet to RH5, I recieve: "Temporary failure in name resolution:
Illegal seek" and host disconnects.


Version-Release number of selected component (if applicable):
Red Hat Enterprise Linux Client release 5 (Tikanga)
telnet-server-0.17-38.el5

How reproducible:
Just telnet :)
If you enter the clients IP and name in /etc/hosts or use a DNS server it works
as it should. Seems like a bug that cant handle that reverse lookup cant be done.

I havent checked whether or not the DNS server have to have an A Name record or not 

Steps to Reproduce:
1. Rename /etc/resolv.conf to /etc/resolv.conf.org
2. Remove clients IP and name from /etc/hosts
3. Telnet from client to Server
  
Actual results:


Expected results:


Additional info:

Comment 1 Harald Hoyer 2007-08-01 09:59:17 UTC

starting the telnetd with "-c" should help in this case..

Comment 2 Kenneth Hansen 2007-08-01 21:15:46 UTC

Thank for the reply.

That flag pointed me to Bug 223448 (was curious about what it meant :)

-c           This option disables reverse dns checking. Of course that
              security is lower with this option

I have tried with "server_args = -c" and "server_args = in.telnetd -c" in
/etc/xinetd.d/telnet and restarted xinetd.
when trying to telnet to the server I get:

Trying 192.168.1.109...
Connected to 192.168.1.109.
Escape character is '^]'.
in.telnetd: invalid option -- c
Usage: telnetd [-debug] [-D (options|report|exercise|netdata|ptydata)]
         [-h] [-L login_program] [-n] [port]
Connection closed by foreign host.

Am I doing something wrong? :)

Comment 3 Harald Hoyer 2007-08-02 09:09:42 UTC

$ cat /etc/xinetd.d/telnet
# default: on
# description: The telnet server serves telnet sessions; it uses \
#       unencrypted username/password pairs for authentication.
service telnet
{
        flags           = REUSE
        socket_type     = stream        
        wait            = no
        user            = root
        server          = /usr/sbin/in.telnetd
        server_args     = -c
        log_on_failure  += USERID
        disable         = no
}

works for me

Comment 4 Harald Hoyer 2007-08-02 09:15:36 UTC

ah, oh... different version in RHEL5 without the "-c" patch :-/ sorry...
also see bug #248063

Comment 5 Kenneth Hansen 2007-08-04 23:27:19 UTC

Be happy to, but Bugzilla disagress :)

You are not authorized to access bug #248063 :(

Comment 6 Kenneth Hansen 2007-08-04 23:31:07 UTC

Btw the way, going on 2 week vacation now...yiihaaa

But will check as soon as I get back..maybe earlier if I'm in any ahem sober
state :)

Comment 7 Adam Tkac 2007-09-03 08:49:39 UTC


*** This bug has been marked as a duplicate of 253392 ***