Hack 14. Debug SSH Client Session

Sometimes it is necessary to view debug messages to troubleshoot any SSH connection issues. pass -v (lowercase v) option to the ssh as shown below to view the ssh debug messages.

Example without SSH client debug message:

localhost$ ssh -l jsmith remotehost.example.com

warning: Connecting to remotehost.example.com failed: No address associated to the name

Example with SSH client debug message:

locaclhost$ ssh -v -l jsmith remotehost.example.com

debug: SshConfig/sshconfig.c:2838/ssh2_parse_config_ext: Metaconfig parsing stopped at line 3.

debug: SshConfig/sshconfig.c:637/ssh_config_set_param_verbose: Setting variable ‘VerboseMode’ to ‘FALSE’.

debug: SshConfig/sshconfig.c:3130/ssh_config_read_file_ext: Read 17 params from config file.

debug: Ssh2/ssh2.c:1707/main: User config file not found, using defaults. (Looked for ‘/home/jsmith/.ssh2/ssh2_config’)

debug: Connecting to remotehost.example.com, port 22… (SOCKS not used)
warning: Connecting to remotehost.example.com failed: No address associated to the name