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Linux / Unix: Disable OpenSSH Host Key Checking

I've a remote Unix server running with OpenSSH remote login service. The openssh is configured for passwordless login using ssh keys. Our ISP allows to boot all Linux servers into the rescue mode. It allow us to bring a server online remotely in order to troubleshoot system problems that would normally only be resolved by an OS Reload (such as accidentally deleting files or wrong firewall configurations blocking ssh access). When server boots into a remote rescue mode I can connect using SSH. They SSH keys will not be the same in the rescue mode so I get key mismatch messages as SSH keys are re-generated on each boot:

Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
Please contact your system administrator.
Add correct host key in /home/user/.ssh/known_hosts to get rid of this message.
Offending key in /home/user/.ssh/known_hosts:1
RSA host key for www.cyberciti.biz has changed and you have requested strict checking.
Host key verification failed.

How do I ignore OpenSSH hos key checking from my Apple OS X laptop while login using the ssh?
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passwd: pam_chauthtok(): conversation failure Error and Solutions

I am trying to change my Unix / Linux user account password using the passwd command. But, I am getting the following error:

passwd: pam_chauthtok(): conversation failure


passwd: pam_chauthtok(): error in service module

How do I fix this problem on Unix like operating systems?
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SSH: Agent Admitted Failure To Sign Using The Key Error And Solution

I've recently regenrated and uploaded a new public ssh-key using the ssh-copy-id command. Now I'm getting the following error:

ssh root@server3
Agent admitted failure to sign using the key.
root@server3's password:

How do I fix this problem?
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OpenBSD: Install Firefox Web Browser

How do I install Mozilla Firefox which is a free and open source web browser under OpenBSD operating systems?
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No xauth Program; Cannot Forward With Spoofing Error and Solution

I want to use my local machine as the X server over ssh. But when I try to run ssh -X -v user@server1.example.com to the remote machine, I get the following error:

debug1: Remote: No xauth program; cannot forward with spoofing

How do I fix this problem and use X over ssh?
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OpenBSD: Install nmap Network Port Scanner Security Tool

How do I install nmap network security and auditing tool under OpenBSD operating system?
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Linux / UNIX: scp / rsync File Name With a Colon (:) In It

How do I copy a file with a colon punctuation (:) name in it. When I type the following command to copy "file:name.txt" to a remote host called server1:

scp file:name.txt user@server1:/path

I get the following error:

ssh: Could not resolve hostname s: Name or service not known

How do I copy file with scp or rsync with a colon in it?
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Linux / UNIX: Kill Unresponsive SSH Session

Sometime my ssh session just stops working because of the internet connection problem. I tried pressing CTRL+Z and CTRL+C to terminate session, but failed to work. How do I properly kill a hung SSH session without killing my local terminal or using kill command?
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Linux / UNIX: Speed up SSH X11 Forwarding

I've an CentOS based server and Ubuntu based desktop pc. I'm connecting to my CentOS using ssh X11 forwarding feature. However, speed over the Internet is pretty slow for certain apps such as VMWare console. How do I speed up OpenSSH X11 forwarding using Linux / UNIX desktop system?
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OpenBSD Command: See PCI Device Information

How do I see PCI devices information under OpenBSD operating systems using command line interfaces?
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