HPC Cluster ELSA3 Host Key Change - Revision history

Admin: /* SSH on MacOS X/MS-Windows/Linux */

2026-04-30T15:17:51Z

SSH on MacOS X/MS-Windows/Linux

← Older revision		Revision as of 15:17, 30 April 2026
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	== SSH on MacOS X/MS-Windows/Linux ==		== SSH on MacOS X/MS-Windows/Linux ==
	When attempting to use the terminal SSH client, you will see a message similar to the screenshot below stating '''WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!''', followed by some additional "scary" text and finally the message that the '''Host key verification has failed'''. Note that the text may vary slightly based on the operating system (Mac/Windows/Linux) you are using. ~~This was~~ captured on a Mac.		When attempting to use the terminal SSH client, you will see a message similar to the screenshot below stating '''WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!''', followed by some additional "scary" text and finally the message that the '''Host key verification has failed'''. Note that the text may vary slightly based on the operating system (Mac/Windows/Linux) you are using. These screenshots were captured on a Mac.

	[[File:MacOSX-host-key-change.png]]		[[File:MacOSX-host-key-change.png]]

Admin: /* Remote Host Key/Identification Changed Error */

2026-04-30T15:10:35Z

Remote Host Key/Identification Changed Error

← Older revision		Revision as of 15:10, 30 April 2026
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	After the existing host key has been removed, you can run the <code>ssh</code> command in your terminal again. This time it will ask you to accept the new host key. If accepted, it won't ~~ask you~~ again ~~the next time~~. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.		After the existing host key has been removed, you can run the <code>ssh</code> command in your terminal again. This time it will ask you to accept the new host key. If you accepted it, you won't be asked again. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.

	[[File:MacOSX-accept-host-key.png]]		[[File:MacOSX-accept-host-key.png]]

Admin at 15:09, 30 April 2026

2026-04-30T15:09:10Z

← Older revision		Revision as of 15:09, 30 April 2026
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	=== Remote Host Key/Identification Changed Error ===		= Remote Host Key/Identification Changed Error =

	When trying to connect to '''elsa.hpc.tcnj.edu''' using SSH after the ELSA3 upgrade, you will probably get an error about the host key or host identification changed.		When trying to connect to '''elsa.hpc.tcnj.edu''' using SSH after the ELSA3 upgrade, you will probably get an error about the host key or host identification changed.

Admin at 15:07, 30 April 2026

2026-04-30T15:07:48Z

← Older revision		Revision as of 15:07, 30 April 2026
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	When trying to connect to '''elsa.hpc.tcnj.edu''' using SSH after the ELSA3 upgrade, you will probably get an error about the host key or host identification changed.		When trying to connect to '''elsa.hpc.tcnj.edu''' using SSH after the ELSA3 upgrade, you will probably get an error about the host key or host identification changed.

	Below are instructions on how to resolve this error when using the command-line SSH program on Mac OS X, but the commands are identical if you are using Linux or the Microsoft Windows built-in SSH client. Near the bottom of this page are instructions if you are on Microsoft Windows and using PuTTY or MobaXterm SSH client software.		Below are instructions on how to resolve this error when using the command-line SSH program on Mac OS X, but the commands are identical if you are using Linux or the Microsoft Windows built-in SSH client. Near the bottom of this page are instructions if you are on Microsoft Windows and using PuTTY or MobaXterm SSH client software. If you are using a different SSH client, you will need to consult its documentation for instructions on how to resolve host key issues.

	== SSH on MacOS X/MS-Windows/Linux ==		== SSH on MacOS X/MS-Windows/Linux ==

Admin: /* MobaXterm on Microsoft Windows */

2026-04-30T15:06:06Z

MobaXterm on Microsoft Windows

← Older revision		Revision as of 15:06, 30 April 2026
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	== MobaXterm on Microsoft Windows ==		== MobaXterm on Microsoft Windows ==
	Resolving the host key/identification change when using MobaXterm is ~~pretty~~ straightforward. Simply click the '''OK''' button to replace the old host key with the new one.		Resolving the host key/identification change when using MobaXterm is straightforward. Simply click the '''OK''' button to replace the old host key with the new one.

	[[File:MobaXterm-host-key-change.png]]		[[File:MobaXterm-host-key-change.png]]

Admin: /* SSH on MacOS X/MS-Windows/Linux */

2026-04-30T15:05:07Z

SSH on MacOS X/MS-Windows/Linux

← Older revision		Revision as of 15:05, 30 April 2026
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	After the existing host key has been removed, you can run the <code>ssh</code> command in your terminal again. This time it will ask you to accept the new host key~~. You will only be asked this once~~. If accepted, it won't ask you again the next time. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.		After the existing host key has been removed, you can run the <code>ssh</code> command in your terminal again. This time it will ask you to accept the new host key. If accepted, it won't ask you again the next time. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.

	[[File:MacOSX-accept-host-key.png]]		[[File:MacOSX-accept-host-key.png]]

Admin: /* SSH on MacOS X/MS-Windows/Linux */

2026-04-30T15:04:24Z

SSH on MacOS X/MS-Windows/Linux

← Older revision		Revision as of 15:04, 30 April 2026
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	After the existing host key has been removed, you can run the ssh command in your terminal again. This time it will ask you to accept the new host key. You will only be asked this once. If accepted, it won't ask you again the next time. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.		After the existing host key has been removed, you can run the <code>ssh</code> command in your terminal again. This time it will ask you to accept the new host key. You will only be asked this once. If accepted, it won't ask you again the next time. You need to type the full word <code>yes</code> and press the ENTER/RETURN key.

	[[File:MacOSX-accept-host-key.png]]		[[File:MacOSX-accept-host-key.png]]

Admin: /* SSH on MacOS X/MS-Windows/Linux */

2026-04-30T15:03:44Z

SSH on MacOS X/MS-Windows/Linux

← Older revision		Revision as of 15:03, 30 April 2026
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	To resolve the issue, you need to remove the old host key for elsa.hpc.tcnj.edu so that you can accept the new one. To do so, run the command <code>ssh-keygen -R elsa.hpc.tcnj.edu</code> in the terminal. Your output should be similar to the screenshot below. Again, it may vary based on your operating system, but you want to see that it found '''elsa.hpc.tcnj.edu''' and updated the file.		To resolve the issue, you need to remove the old host key for '''elsa.hpc.tcnj.edu''' so that you can accept the new one. To do so, run the command <code>ssh-keygen -R elsa.hpc.tcnj.edu</code> in the terminal. Your output should be similar to the screenshot below. Again, it may vary based on your operating system, but you want to see that it found '''elsa.hpc.tcnj.edu''' and updated the file.

	[[File:MacOSX-remove-host-key.png]]		[[File:MacOSX-remove-host-key.png]]
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	[[File:MacOSX-accept-host-key.png]]		[[File:MacOSX-accept-host-key.png]]

	That's it. You can now continue to use the ELSA3 HPC cluster.		That's it. You can now continue to use the ELSA3 HPC cluster.


	== PuTTY on Microsoft Windows ==		== PuTTY on Microsoft Windows ==

Admin at 15:03, 30 April 2026

2026-04-30T15:03:13Z

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 [[File:MobaXterm-host-key-change.png]]

Admin: Created page with "File:MacOSX-host-key-change.png File:MacOSX-remove-host-key.png File:MacOSX-accept-host-key.png File:Putty-host-key-change.png File:MobaXterm-host-key-change.png"

2026-04-30T14:39:34Z

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