SSH Authentication Problems


Hello, I am a new Nagios user and have been trying to get CHECK_BY_SSH working with no success. I am working in a large scale environment with many Linux servers using kerberos authentication. While logged into a linux box with my kerberos account and SSHing to another client linux box, I am able to SSH with no password prompt (SSH is kerberized). I have a separate nagios account to run nagios. However, this account has no access privileges to other linux servers, therefore it cannot SSH to those servers. I have been trying to run CHECK_BY_SSH with the -l flag using the kerberos account to ssh to other servers. However, I am getting one of the following errors with different servers:

"Remote command execution failed: Host key not found from the list of known hosts. "
"Remote command execution failed: You have no controlling tty and no DISPLAY. Cannot read passphrase. "

This is very odd to me. I am able to SSH just fine from the shell using my kerberos account. However, when running the CHECK_BY_SSH with the -l flag using my kerberos account, I am getting errors. Do I have to do some sort of configuration to use kerberized SSH instead of SSH keys? In addition, if I want to view the source for the Nagios plugins which are precompiled, how can I view them? Thanks in advance everyone!