DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet Switch User Manual
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Password – This parameter should be chosen if the administrator wishes to use an
administrator-defined password for authentication. Upon entry of this parameter, the Switch
will prompt the administrator for a password, and then to re-
type the password for
confirmation.
Public Key – This parameter should be chosen if the administrator wishes to use the
publickey on a SSH server for authentication.
Host Name Enter an alphanumeric string of no more than 32 char acters to identify the remote SSH user.
This parameter is only used in conjunction with the Host Based choice in the Auth. Mode
field.
Host IP Enter the corresponding IP address of the SSH user. This parameter is only used in
conjunction with the Host Based choice in the Auth. Mode field.
Click Apply to implement changes made.
NOTE: To set the SSH User Authentication parameters on the Switch, a User Acc ount
must be previously configured. For more information on configuring loca l User Ac counts on
the Switch, see the User Accounts section of this manual located in th e Configuration
section.
The TACACS/XTACACS/TACACS+/RADIUS commands allow users to secur e access to the Switch using the
TACACS/XTACACS/TACACS+/RADIUS protocols. W hen a user logs in to the Switch or tries to access the
administrator level privilege, he or she is prompted for a password. If TACACS/X TACACS/TACACS+/RADIUS
authentication is enabled on the Switch, it will contact a TACACS/XTACACS/TACAC S+/RADIUS server to verif y the
user. If the user is verified, he or she is granted access to the Switch.
There are currently three versions of the TACACS security protocol, each a separate entity. The S witch's software
supports the following versions of TACACS:
TACACS (Terminal Access Controller Access Control System) - Provides password checking and
authentication, and notification of user actions for security purposes utilizing via one or m ore centralized
TACACS servers, utilizing the UDP protocol for packet transmiss ion.
Extended TACACS (XTACACS) - An extension of the TACACS protocol with the ability to provide mor e
types of authentication requests and more types of response codes t han TACACS. This protoco l also uses
UDP to transmit packets.
TACACS+ (Terminal Access Controller Access Control System plus) - Provides detailed access control
for authentication for network devices. TACACS+ is facilitated through Authentic ation commands via one or
more centralized servers. The TACACS+ protocol encrypts all traf fic between the S witch and the TACAC S+
daemon, using the TCP protocol to ensure reliable delivery
In order for the TACACS/XTACACS/TACACS+/RADIUS security function to work pr operly, a
TACACS/XTACACS/TACACS+/RADIUS server must be configured on a d evice other than the Switch, called an
Authentication Server Host and it must include usernames and passwords for authentication. When the user is
prompted by the Switch to enter usernames and passwords for authentic ation, the Switch contacts the
TACACS/XTACACS/TACACS+/RADIUS server to verify, and the ser ver will respond with one of three messages:
The server verifies the username and password, and the user is granted nor mal user privileges on the Switch.
The server will not accept the username and password and the user is denie d access to the Switch.
The server doesn't respond to the verification query. At this point, the Switch receives the timeout f rom the
server and then moves to the next method of verification configured in the m ethod list.
The Switch has four built-in Authentication S erver Groups, one f or each of the TACACS, XTACACS , TACACS+ and
RADIUS protocols. These built-in Authentication Server Groups are used to au thenticate users trying to a ccess the
Switch. The users will set Authentication Server Hosts in a preferable order in the built-in Authentication Server
Groups and when a user tries to gain access to the Switch, the Switch will ask the f irs t Authen ticat ion Server Hosts for
authentication. If no authentication is made, the second serv er host in th e list wil l be queried, an d so on. T he built-in
Authentication Server Groups can only have hosts that are running the specified protocol . For exam ple, the TACACS
Authentication Server Groups can only have TACACS Authentication Ser ver Hosts.