"cannot resolve network address for KDC in requested realm" - Certificate or Kerberos ticket acquisitions

In trying to obtain an MIT personal certificate or Kerberos tickets, I enter my username and hit OK or Submit, but I receive the following error:

cannot resolve network address for KDC in requested realm

Solution

One cause of this error may be that you are using your full email address, such as "johnsmith@mit.edu".
- Instead, type only the username, such as "johnsmith".
Another possible cause of the error will be if there is no network connectivity.
- Check whether you are able to browse the web, such as http://web.mit.edu and http://google.com.
Make sure Kerberos for Windows or Kerberos Extras for Macintosh are up to date, using the most recent version:
- Kerberos for Windows
- Kerberos Extras for Macintosh
The realm should be ATHENA.MIT.EDU . Please note the capitalization.
If you continue to receive the error, contact the IS&T Help Desk, at (617)253-1101, or helpdesk@mit.edu.