Explanation https://community.cisco.com/t5/other-network-architecture/out-of-band-router-access/td-p/333295 The "transport output none" command prevents any protocol connection made from R1. Therefore our SSH connection to 192.168.12.2 was refused. In order to fix this problem we can configure "transport output ssh" under "line console 0" of R1. Note: The parameter "-l" specifies the username to log in as on the remote machine.