Allied Telesis AT-9724TS - Manual (Page 86)

Port-Based Network Access Control
Figure 6- 73. Example of Typical Port-Based Configuration
Once the connected device has successfully been authenticated, the Port then becomes Authorized, and all subsequent traffic on the Port is not subject to access
control restriction until an event occurs that causes the Port to become Unauthorized. Hence, if the Port is actually connected to a shared media LAN segment
with more than one attached device, successfully authenticating one of the attached devices effectively provides access to the LAN for all devices on the shared
segment. Clearly, the security offered in this situation is open to attack.
MAC-Based Network Access Control
Figure 6- 74. Example of Typical MAC-Based Configuration
In order to successfully make use of 802.1X in a shared media LAN segment, it would be necessary to create “logical” Ports, one for each attached device that
required access to the LAN.The Switch would regard the single physical Port connecting it to the shared media segment as consisting of a number of distinct
logical Ports, each logical Port being independently controlled from the point of view of EAPOL exchanges and authorization state.The Switch learns each
attached devices’ individual MAC addresses, and effectively creates a logical Port that the attached device can then use to communicate with the LAN via the
Switch.
85 Allied Telesyn AT-9724TS High-Density Layer 3 Stackable Gigabit Ethernet Switch
AT-9724TS Switch
Uncontrolled Port
Controlled Port - port blocked
RADIUS
Server
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
802.1X
Client
AT-9724TS Switch
802.1X Client 802.1X Client 802.1X Client 802.1X Client RADIUS
Server
Uncontrolled Port
Controlled Port - port blocked