Finally got new RedHat server to authenticate to Windows 2003 server via Kerberos. There are a few things to watch out for but the article I posted on Wednesday was the most helpful. You also have to remember to modify the sshd_config file to allow login via ssh and add the user accounts in /etc/passwd. Note also that if you are trying to login to an account that was created before you installed Kerberos on the KDC, you may need to change the password on that account before it will work.