Networker Device not able to scan

@Jesus Ramirez , Are trying to scan a device(not sure what type) which is configured to your storage node or are you trying to add a new tape device attached to the storage node to be configured in NetWorker?

In either cases you might try and clear the peer information on the storage node and also on the Networker server for the respective storage node and try again.

If these both are not the issue that you are facing a little more context and env details would help us to help you.

Is the NW storage node OK? This due to the "Authentication error; why = Server rejected credential". That can occur when the NW NSR peer information from a client, does not match the NSR peer information that the NW server has of the client (in this case a NW SN). The NW daemon.raw would contain information about the error and gives a suggestion what to do about it:

"nsrexecd GSS critical An authentication request from was denied. The 'NSR peer information' provided did not match the one stored by . To accept this request, delete the 'NSR peer information' resource with the following attributes from 's NSRLA database: name: ; NW instance ID: xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx-xxxxxxxx; peer hostname: "

Can you backup the NW SN itself even? O r setup an "nsradmin -s -p nsrexecd" session to it, querying its client settings?

Also that can happen when the NW client version is too low on the NW SN, as it should be the same version as on the NW server to not have issues (NW cloning for example is very picky about needing to have the exact same NW version as the NW server).