I have the following network topology:
workstation <-> network_device <-> authentication_server
When I log in to network_device
from workstation
over SSH, then network_device
checks with TACACS+ authentication_server
if I have a permission to log in, what are my access rights for that network_device
, etc. When I execute ssh -o LogLevel=quiet network_device
in workstation
, then I do not see the network device banner, but I do see the following prompt:
$ ssh -o LogLevel=quiet network_device
TACACS authentication!
Password:
$
This TACACS authentication!
string is set by authentication_server
. When I execute ssh -vvv -o LogLevel=quiet network_device
, then I see that this banner and password prompt seem to have different message IDs. Banner:
debug3: receive packet: type 53
debug3: input_userauth_banner
*************************************************
* Access limited to Authorized Users only *
*************************************************
Password prompt:
debug3: receive packet: type 60
debug2: input_userauth_info_req
debug2: input_userauth_info_req: num_prompts 1
TACACS authentication!
Password:
Does OpenSSH client LogLevel
option work in a way that it simply filters certain message IDs depending on LogLevel
value? Manual page does not explain, how exactly LogLevel
decides what to show:
LogLevel
Gives the verbosity level that is used when logging messages from ssh(1). The possible values are: QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is
INFO. DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify higher levels of verbose output.