Software Tips
Last revision November 3, 2011
Disable kerberos keys if trouble connecting with SecureCRT or SecureFX
ArcMap extensions may need to be activated
3/23/09, revised 11/3/11 - Disable kerberos keys if trouble connecting with SecureCRT or SecureFX
Sometimes, an ssh connection attempt with the SecureCRT program or an sftp connection attempt with the SecureFX program running on Windows will fail to connect with this error message:
Internal credentials cache error (Kerberos error 196)
This error can happen when SecureCRT or SecureFX tries to forward your kerberos credential from your login to Windows to the remote system to authenticate you, and the remote system does not accept kerberos authentication. To work-around this error, you must disable the use of kerberos key exchange to that server, as shown in this note.
SecureCRT and SecureFX are companion programs and work the same way. The screen-shots shown here are from SecureCRT. Use the same method for SecureFX.
Key exchange methods are set on a per-session basis. You must first define a session for your connection before you can disable kerberos key exchange. When you open the SecureCRT (or SecureFX) program, it normally brings up the Connect dialog box, as shown below. If not, select it from the "File" menu.
If you do not have a session defined for your intended destination, click on the third icon from the left, which is the "New Session" button, shown circled in red in the the screenshot above. This brings up a "New Session Wizard" where you can define basic session parameters. Leave all configurations (SSH2 and SFTP) at their default values and just fill in the "Hostname" field. The wizard will then add this newly defined session to your session menu list.
Now that you have defined a session for this server, right-click on its name in the "Connect" window and select "Properties" from the contextual menu, as shown below:
This opens the "Session Options" window, as shown below:
The left side of "Session Options" is a menu of all the options you can configure. Click on "SSH2". This will bring up the SSH2 connection options, as shown in the screenshot above. The "Key exchange" section on the right shows all the possible key exchange methods that SecureCRT or SecureFX will try. By default, they are all checked (enabled). UNcheck (disable) the two options labelled Kerberos and Kerberos w/ Group Exchange. Close the "Session Options" window and continue with your connection.
This new setting will persist for your account on this computer, until such time as the lab computers are rebuilt with a new software image at the end of the quarter.
12/10/08, revised 11/3/11 - ArcMap extensions may need to be activated
The ArcMap program contains many "Analyst" extensions that are not active by default. This is because they require a separate license. Stanford has a site-license for all features, so you can use these extensions as well. All extensions should be active already on the A-65 computers. If an extension you need does not run, check to make sure it is enabled.
Extension activation status is stored on a per-user and per-computer basis. Each person using the lab may see different active extensions on each computer he/she uses.
To check Extension status, open the ArcMap program. Close the "ArcMap - Getting Started" window (or select your map if you intend to work on it now). Select the Extensions item from the Customize menu. The window that opens should show a check in the box next to each Extension name, as shown in this screenshot:
As you can see, all extensions should be enabled (checked) by default. If an extension you need is not checked, simply click in the box next to the name to enable it. When you are done, click the Close button to save your changes.
These settings will persist for your account on this computer, until such time as the lab computers are rebuilt with a new software image at the end of the quarter.
