Location for PuTTY Tunnel Information

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PuTTY stores information about sessions you have created to connect to a particular host in the Windows Registry at HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions. If you want to view the SSH tunnels configured for a particular host, i.e., the port forwarding settings for that host, you can navigate to HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\SessionName\PortForwardings where SessionName is the name you have given to the session associated with the host. E.g., suppose you regularly establish an SSH connection to www.example.com and have named a session for that site MySite. You could navigate to HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\MySite\PortForwardings to find the port forwardings settings. If you had named the session My Site, there would be a %20 in the session name stored in the registry as %20 is an HTML representation for the space character. You can doubleclick on the PortForwardings key in the right pane of the registry window to see the values stored in the key. You might see something like the following:

L22011=192.168.0.11:22,L33018=192.168.0.18:33018

The above value indicates that, when you establish a session to the host www.example.com, port forwarding is set up so that port 22011 is set on the local system, i.e., the system from which you are connecting, to be forwarded to the SSH port 22 on another host at IP address 192.168.0.11. So if you establish an SSH session to www.example.com, you can subsequently establish another SSH session to 127.0.0.1 on port 22011 on the local system, from which you established the first SSH session, to connect to port 22 on the system at 192.168.0.11. Likewise, if the system at 192.168.0.18 is listening on port 33018 for a connection, you can connect to 127.0.0.1:33018, i.e., port 33018 on the localhost address (127.0.0.1), which will be forwarded to the same port on 192.168.0.18. The local and remote port numbers don't have to be the system. E.g., if you wished to establish a Remote Desktop Protocol (RDP) port on 192.168.0.18, you could change the port forwardings in PuTTY to list the remote port as 3389 or you could edit the entry in the registry by right-clicking on PortForwardings and choosing Modify and then changing the L33018=192.168.0.18:33018 to L33018=192.168.0.18:3389.

If you wish to transfer all of the settings for a session, including the PortForwardings, you can right-click on the session name in the left pane of the window registry and choose File and Export from the Registry Editor window. You can then save the session settings as a registry file with a .reg file extension. If you only want to save the port forwarding settings, e.g., to transfer to another system or user, you could edit the .reg file with the Windows Notepad editor by right-clicking on the file and choosing Open with and then Notepad. You could then delete all of the lines in the file that appeared after [HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\MySite] but the one pertaining to port forwarding, i.e., L22011=192.168.0.11:22,L33018=192.168.0.18:33018. The file would then contain only the following lines:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\MySite]
"PortForwardings"="L22011=192.168.0.11:22,L33018=192.168.0.18:33018"

If you then saved the file, you could transfer it to another computer or user account on the same system and double-click on it to have the port forwarding settings added to the registry, if there was already a session named MySite in the registry for the user for which you wished to import the settings. If there wasn't such a session for the destination account, then don't remove any lines from the registry file, e.g., MySite.reg, but simply transfer the file to the destination account and double-click on it to enter all of the settings for the session into the registry. When you double-click on the file to add the information within it to the Windows Registry, you will see a warning message that "Adding information can unintentionally change or delete values and cause components to stop working correctly." You will be prompted "Are you sure you want to continue?" Click on the Yes button. You should then see another window open informing you that the keys and values contained in the file have been successfully added to the registry.

If you just wish to view the port forwarding sessions, you can do so by navigating to the relevant spot in the registry or you can query the registry from a command line interface (CLI) by opening a command prompt window and issuing a reg query command. E.g.:

C:\>reg query HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\MySite /v PortForwardings

HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\ACI
    PortForwardings    REG_SZ    L22011=192.168.0.11:22,L33018=192.168.0.18:33018 


C:\>

If you wished to view all of the settings for a session, you could use the command reg query HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions\MySite, instead.

If you wished to transfer the settings for all sessions somewhere else, you could right click on Sessions under HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions and choose Export or choose File and Export... from the Windows Registry Editor and then double-click on the .reg file you create while logged in under a different account to transfer the settings to that other account. Or you could do the same thing for HKEY_CURRENT_USER\SOFTWARE\SimonTatham to transfer all of the PuTTY information, including the Jumplist values. The Jumplist contains a list of recent sessions.

Registry - SimonTatham

Related:

  1. Port Forwarding RDP with PuTTY
    Date: May 8, 2012
  2. Using PuTTY to set up a SOCKS Proxy Connection
    Date: February 15, 2015
  3. Port forwarding to another device with PuTTY
    Date: June 12, 2015
  4. Testing access to a website using PuTTY
    Date: July 5, 2015
  5. Changing the appearance of a PuTTY session
    Date: February 7, 2016