LinuxQuestions.org
Latest LQ Deal: Complete CCNA, CCNP & Red Hat Certification Training Bundle
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 09-15-2008, 01:53 AM   #1
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Rep: Reputation: 51
Unable to ssh through putty??


I am really surprised by this redhat box.I am able to login through ssh:// but am not able to login through putty.
it says: access denied permission.

And Also everytime I have to delete known_hosts file from /root/.ssh/ directory.

What might be the issue?

Pls help
 
Old 09-15-2008, 02:28 AM   #2
matthewg42
Senior Member
 
Registered: Oct 2003
Location: UK
Distribution: Kubuntu 12.10 (using awesome wm though)
Posts: 3,530

Rep: Reputation: 63
What sort of authentication are you using? password, public key...?
 
Old 09-15-2008, 03:22 AM   #3
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
Its Completely a new RHEL4U6 system.I dint do any change to the system.It was installed yesterday.All I find is whenever I ssh through any other machine I find "SOMEONE NASTY IS GOING ON YOUR MACHINE" and it says to delete /root/.ssh/known_hosts file.But when I delete that file,it allows me.After Sometime If I will login through any other machine,it prevents me saying the same error.Again,I delete the file..and it goes on..

While through putty,it say :Access Denied" error
 
Old 09-15-2008, 03:26 AM   #4
billymayday
LQ Guru
 
Registered: Mar 2006
Location: Sydney, Australia
Distribution: Fedora, CentOS, OpenSuse, Slack, Gentoo, Debian, Arch, PCBSD
Posts: 6,678

Rep: Reputation: 122Reputation: 122
Putty from same machine?
 
Old 09-15-2008, 04:23 AM   #5
matthewg42
Senior Member
 
Registered: Oct 2003
Location: UK
Distribution: Kubuntu 12.10 (using awesome wm though)
Posts: 3,530

Rep: Reputation: 63
The known_hosts file keeps a list of machines to which you have connected, and a cryptographic id of that machine. The point of the file is to make sure that when you re-connect to a machine which you have previously connected to, that it is the same machine.

What causes the message you see is that the remote machine's ID has changed. This can happen if the machine's identification keys are re-generated (e.g. you re-install the OS on the machine, or run the server key generation routine.

What it is trying to prevent is some attacker hijacking the machine's IP address and pretending to be that machine. An attacker might do this to get your password - if the attacker's machine has stolen the IP address of your machine, and you try to connect to it with a password, the attacker can steal your password.

If you are the owner/admin of the machine to which you are trying to connect, you should know if you have recently re-installed the OS, or re-generated the server keys. If you know you have done this, then it's fine to delete the known_hosts file. You will need to do this every time you re-generate the server keys or re-install the OS. The solution to the problem is simply not to regenerate the server keys. There is no reason to do it unless there is some known problem, such as the recent debian bug in ssh.

However, if you get this message at un-expected times, it is possible that someone is trying to steal your password.
 
Old 09-15-2008, 04:42 AM   #6
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
By mistake I had run :
chmod -R 777 /root
Whenever I am trying logging in its hang on after providing password.
I checked with logs and it saysam_timestamp_checkam_timestamp: "/" permissions are lax

Whats That error all about?
 
Old 09-15-2008, 04:43 AM   #7
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
And Now I am able to login as :

Code:
login as: root
root@10.14.236.132's password:
Last login: Mon Sep 15 14:39:59 2008 from 10.14.2.254
xset:  unable to open display ""
xset:  unable to open display ""
[root@Mplus ~]#
But after sometime It Again hanged...Whats Going On..Surprising
 
Old 09-15-2008, 04:44 AM   #8
billymayday
LQ Guru
 
Registered: Mar 2006
Location: Sydney, Australia
Distribution: Fedora, CentOS, OpenSuse, Slack, Gentoo, Debian, Arch, PCBSD
Posts: 6,678

Rep: Reputation: 122Reputation: 122
/root isn't normally world readable.

What else did you do?

Was it chmod -R 777 /root

or chmod -R 777 /

?
 
Old 09-15-2008, 05:13 AM   #9
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
No,
It was chmod -R 777 /root
 
Old 09-15-2008, 05:20 AM   #10
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
Again....Its Just Sucks !!!



I thought have fixed the X session issue.Resolution: I tried running the following command

echo "export DISPLAY=:0" >> ~/.bashrc



And it solved the problem.

But When I am logging through putty it works ...but aftertime the putty goes inactive.

Why it happening?
 
Old 09-15-2008, 05:21 AM   #11
billymayday
LQ Guru
 
Registered: Mar 2006
Location: Sydney, Australia
Distribution: Fedora, CentOS, OpenSuse, Slack, Gentoo, Debian, Arch, PCBSD
Posts: 6,678

Rep: Reputation: 122Reputation: 122
RHEL5, /root should be 750

The files within depend.
 
Old 09-15-2008, 05:22 AM   #12
billymayday
LQ Guru
 
Registered: Mar 2006
Location: Sydney, Australia
Distribution: Fedora, CentOS, OpenSuse, Slack, Gentoo, Debian, Arch, PCBSD
Posts: 6,678

Rep: Reputation: 122Reputation: 122
This is one muddled thread - where did the X session bit come in?
 
Old 09-15-2008, 05:22 AM   #13
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
Let me tel you something, recently I have upgraded my Redhat Linux from RHEL4U4 to RHEL4U6.

I am now Not able to login through ssh from any other machine too.

Last edited by your_shadow03; 09-15-2008 at 05:24 AM.
 
Old 09-15-2008, 05:23 AM   #14
your_shadow03
Senior Member
 
Registered: Jun 2008
Location: Germany
Distribution: Slackware
Posts: 1,462
Blog Entries: 6

Original Poster
Rep: Reputation: 51
Sorry...Wrongly I entered into that..Pls Ignre it.

Can you go thru my last post...Pls Help

Is there logs entry which I can post for You for making things more simpler?I have no idea whats doing on wrong here?

Last edited by your_shadow03; 09-15-2008 at 05:26 AM.
 
Old 09-15-2008, 05:24 AM   #15
vdx
Member
 
Registered: Aug 2007
Location: The Greate INDIA
Distribution: CentOS, RHEL, Fedora
Posts: 102

Rep: Reputation: 24
check for the 22 no port is open on ur redhat system or not ?
is sshd running ?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
SSH/Putty Linux Newbee Linux - Networking 1 08-06-2008 01:58 PM
[putty&ssh] Who is really good & expert in ssh https tunnelling and firewalling ? Xeratul Linux - General 12 12-03-2006 03:22 AM
Problem with Putty and SSH pcwsp Linux - Software 6 11-18-2006 09:32 AM
SSH and Putty... Linux~Powered Linux - Security 4 06-15-2006 02:50 PM
SSH using putty rkemp Linux - Networking 3 03-06-2004 05:04 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 03:57 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration