Connecting to CS Systems with SSH - Revision history

Pip: /* Using SSH */

2024-10-25T14:46:09Z

Using SSH

2024-03-15T13:24:58Z

Steve410 moved page SSH to Connecting to CS Systems with SSH: Adding specificity to the title.

2024-03-15T13:01:53Z

Additional Resources

2024-03-15T12:56:09Z

2023-02-20T21:02:51Z

Windows

2020-04-13T15:29:51Z

Windows

2020-04-13T14:24:58Z

Configuration

2020-04-13T14:24:41Z

Configuration

2020-04-13T13:15:28Z

Copyediting

2020-04-08T20:31:10Z

SSH Config

← Older revision		Revision as of 14:46, 25 October 2024
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	ssh ckent1@ugrad5.cs.jhu.edu		ssh ckent1@ugrad5.cs.jhu.edu
		+
		+	The first time you connect to a remote system, your client will show you the server's ''key fingerprint''. For a command line SSH client, that will probably look something like this:
		+
		+	The authenticity of host 'ugradx.cs.jhu.edu (128.220.224.100)' can't be established.
		+	ED25519 key fingerprint is SHA256:IjfRPzfeCGJLUVNFXeE5Tg0SRc/0JXdKxzQX+LN4SZg.
		+	This key is not known by any other names.
		+	Are you sure you want to continue connecting (yes/no/[fingerprint])?
		+
		+	This is how your SSH client verifies the identity of the remote system. For one of our systems, you should verify that the key fingerprint shown matches the one for that system on our [[SSH Keys]] page. (That page also has some information on how to pre-approve all of our systems so you don't get this message for them.)
		+
		+	In general, if you cannot verify a remote system's fingerprint, it's usually okay to just type "yes" here. Your SSH client will remember the remote system's identity and won't print this again, so long as the identity changes. (If the identity does change in the future, your SSH client will warn you about it, and you should check with the owner of the system to make sure this is intentional before continuing.)

	=== Using an Alternate Port ===		=== Using an Alternate Port ===

← Older revision		Revision as of 13:01, 15 March 2024
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	* [https://linux.die.net/man/1/ssh SSH Man Page]		* [https://linux.die.net/man/1/ssh SSH Man Page]
		+	* [[:Category:SSH\|SSH Category]] on the CS IT Support Wiki

	[[Category:SSH]]		[[Category:SSH]]

← Older revision		Revision as of 12:56, 15 March 2024
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	* [https://linux.die.net/man/1/ssh SSH Man Page]		* [https://linux.die.net/man/1/ssh SSH Man Page]

−	[[Category:~~Linux Clients]]~~	+	[[Category:SSH]]
−	~~[[Category:Networking~~]]

← Older revision		Revision as of 21:02, 20 February 2023
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	For X forwarding to work properly on Microsoft Windows, you will need to install an X window server, for example, a program like [https://sourceforge.net/projects/vcxsrv/ VcXsrv].		For X forwarding to work properly on Microsoft Windows, you will need to install an X window server, for example, a program like [https://sourceforge.net/projects/vcxsrv/ VcXsrv].
		+
		+	We don't directly support software installation on personal computers, but we'll note that when using VcXsrv on Windows 10 and 11:
		+
		+	* <kbd>ssh -X</kbd> might not work properly; <kbd>ssh -Y</kbd> might work instead. Note that <code>-Y</code> is slightly less secure. You can read the man pages for the full details, but using <code>-Y</code> causes the X server (on your desktop) to trust the remote system slightly more, which opens it up to some possible-if-unlikely attack vectors. The problem with using <code>-X</code> appears to be related to the use of <code>xauth</code> on the Windows computer. Interested parties are encouraged to read the VcXsrv and OpenSSH documentation to sort out the right configuration to use.
		+	* You need to set the <code>$DISPLAY</code> environment variable before running the command-line OpenSSH client. In PowerShell, that can be done with <kbd>$env:DISPLAY = "localhost:0"</kbd> (or whichever display number VcXsrv is using, if it's not ":0").

	===== macOS =====		===== macOS =====

@@ Line 16: / Line 16: @@
 Since April of 2018, SSH (OpenSSH) comes pre-installed in Microsoft Windows 10 and above and can be used via the command line either by using the '''CMD''' shell or '''Powershell'''.   More information can be found at Microsoft's [https://docs.microsoft.com/en-us/windows-server/administration/openssh/openssh_overview OpenSSH in Windows] page.
-(You also have the option to run a 3rd party product called [https://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY].  However, PuTTY uses different configurations for SSH Keys, X-Forwarding, etc. so, you'll need to find documentation for those items online.  The information you see below is specifically for OpenSSH, not PuTTY.
+You also have the option to run a 3rd party product called [https://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY].  However, PuTTY uses different configurations for SSH Keys, X-Forwarding, etc. so, you'll need to find documentation for those items online.  The information you see below is specifically for OpenSSH, not PuTTY.
 == Using SSH ==

← Older revision	Revision as of 13:24, 15 March 2024
(No difference)

@@ Line 146: / Line 146: @@
   # Default settings for any systems we connect to at jhu.edu:
   Host *.jhu.edu
-      <var>Parameter2</var> <var>Value</var>
+      <var>Parameter1</var> <var>Value</var>
   # Default settings for all hosts we connect to:
   Host *
-      <var>Parameter1</var> <var>Value</var>
+      <var>Parameter2</var> <var>Value</var>
 '''Note:''' If multiple patterns match a host, the settings will stack.  In this case, any host matching <code>Host *.jhu.edu</code> also matches <code>Host *</code>, so the settings from both will apply.  If the same parameter is set in different matching <code>Host</code> sections, the ''first'' one in the file will be the one that takes effect.

@@ Line 144: / Line 144: @@
 When you connect to a host, SSH will scan the config file to determine if there is a matching <code>Host</code> entry for the server you're attempting to connect to.  This allows us to use a wildcard character (*) in this field for pattern matching.  For example:
   # Default settings for all hosts we connect to:
   Host *
       <var>Parameter1</var> <var>Value</var>
-'''Note:''' If multiple patterns match a host, the settings will stack.  In this case, any host matching <code>Host *.jhu.edu</code> also matches <code>Host *</code>, so the settings from both will apply.  If the same parameter is set in different matching <code>Host</code> sections, the ''last'' one in the file will be the one that takes effect.
+'''Note:''' If multiple patterns match a host, the settings will stack.  In this case, any host matching <code>Host *.jhu.edu</code> also matches <code>Host *</code>, so the settings from both will apply.  If the same parameter is set in different matching <code>Host</code> sections, the ''first'' one in the file will be the one that takes effect.
 You can find a list of all parameters available in the [https://linux.die.net/man/5/ssh ssh(5) Man Page].

@@ Line 143: / Line 143: @@
 This will create a SOCKS5 proxy on the local port specified to be able to filter traffic through the server.  This is a great way to create a very simple VPN.
-== SSH Config ==
+=Configuring SSH=
 There are a lot of parameters you can set for your SSH connections, and remembering them can be a chore.  Fortunately there is an easy way to do this with SSH's client configuration file.