D-Link DGS-3048 [98/147] Access authentication control

DGS-3048 Gigabit Ethernet Switch Manual

Trusted Host

Go to the Security folder and click on the Trusted Host link; the following window will appear.

Figure 10- 9.Security IP Management Window

Use security IP management to permit remote stations to manage the Switch. If you choose to define one or more

designated management stations, only the chosen stations, as defined by IP address, will be allowed management privilege

through the web manager or Telnet session. To define a management station IP setting, type in the IP address and click the

Apply button.

Access Authentication Control

The TACACS+ / RADIUS commands let you secure access to the Switch using the / TACACS+ / RADIUS protocols.

When 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+ / RADIUS authentication is enabled on the Switch, it will contact a TACACS+ / RADIUS server to verify 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 Switch's software supports

the following versions of TACACS:

• TACACS+ (Terminal Access Controller Access Control System plus) - Provides detailed access control for

authentication for network devices. TACACS+ is facilitated through Authentication commands via one or more

centralized servers. The TACACS+ protocol encrypts all traffic between the Switch and the TACACS+ daemon,

using the TCP protocol to ensure reliable delivery

In order for the TACACS+ / RADIUS security function to work properly, a TACACS+ / RADIUS server must be

configured on a device 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 authentication,

the Switch contacts the TACACS+ / RADIUS server to verify, and the server will respond with one of three messages:

• The server verifies the username and password, and the user is granted normal user privileges on the Switch.

• The server will not accept the username and password and the user is denied access to the Switch.

• The server doesn't respond to the verification query. At this point, the Switch receives the timeout from the server

and then moves to the next method of verification configured in the method list.

The Switch has four built-in

Authentication Server Groups, one for each of the TACACS+ and RADIUS protocols. These

built-in Authentication Server Groups are used to authenticate users trying to access 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 first Authentication Server Hosts for authentication. If no authentication is

made, the second server host in the list will be queried, and so on. The built-in Authentication Server Groups can only have

hosts that are running the specified protocol. For example, the TACACS Authentication Server Groups can only have

TACACS Authentication Server Hosts.

The administrator for the Switch may set up six different authentication techniques per user-defined method list (TACACS+

/ RADIUS / local / none) for authentication. These techniques will be listed in an order preferable, and defined by the user

for normal user authentication on the Switch, and may contain up to eight authentication techniques. When a user attempts

to access the Switch, the Switch will select the first technique listed for authentication. If the first technique goes through its

Authentication Server Hosts and no authentication is returned, the Switch will then go to the next technique listed in the

server group for authentication, until the authentication has been verified or denied, or the list is exhausted.