SSH Reference Manual

Is the name of a KNOWNHOST entity contained in the SSHCTL.

Cause: The SSH client (e.g. SFTP) tried to access a known host that was frozen.

Effect: The client access to the host is denied. The client connection fails.

Recovery: If access to the host is desired, use the SSHCOM THAW KNOWNHOST command to thaw the

host.

<session id>: client access to known host <known host name> denied, public key changed

Is the name of a KNOWNHOST entity contained in the SSHCTL.

Cause: The public key of the host the SSH client (e.g. SFTP) tried to access does not match the public key

stored for the KNOWNHOST in SSHCTL. Important note: THIS COULD BE CAUSED BY a ”man-in-the-

middle” attack.

Effect: The client access to the host is denied. The client connection fails.

Recovery: Check if the identity of the target host has really been changed. If access to the host is desired, use

the SSHCOM ALTER KNOWNHOST command to alter the public key of the host.

<session id>: client access to unknown host at <host>:<port> denied

Cause: The public key of the host the SSH client (e.g. SFTP) tried to access does not match the public key

stored for the KNOWNHOST in SSHCTL. Important note: THIS COULD BE CAUSED BY a “man-in-the-

middle” attack.

Effect: The client access to the host is denied. The client connection fails.

Recovery: Check if the identity of the target host has really been changed. If access to the host is desired, use

the SSHCOM ALTER KNOWNHOST command to alter the public key of the host.

<session id>: exception during host verification: <error detail>

Is a description of the error condition.

Cause: An unexpected error occurred during the verification of the host the SSH client (e.g. SFTP) connected

to. For example, this could be caused by a problem with accessing the SSHCTL database.

Effect: The client access to the host is denied. The client connection fails.

Recovery: Any corrective action depends on error detail.

<session id>: Authentication failed

Cause: The authentication of the user with the remote SSH server failed.

Effect: The client access to the host is denied. The client connection fails.

Recovery: Additional error information is returned to the SSH client (e.g. SFTP). Check the user’s credentials

(private keys or password) for accuracy. Check if any of the user’s private keys are made known to the SSH

server.

338 • Troubleshooting HP NonStop SSH Reference Manual