DGS-3224TGR Gigabit Ethernet Switch User’s Guide
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Authentication Process
Utilizing the three roles stated above, the 802.1x protocol provides a stable and secure way of authorizing and
authenticating users attempting to access the network. Only EAPOL traffic is allowed to pass through the specified port
before a successful authentication is made. This port is “locked” until the point when a Client with the correct username and
password (and MAC address if 802.1x is enabled by MAC address) is granted access and therefore successfully “unlocks”
the port. Once unlocked, normal traffic is allowed to pass through the port. The following figure displays a more detailed
explanation of how the authentication process is completed between the three roles stated above.
Figure 5- 9. The 802.1x Authentication Process
The D-Link implementation of 802.1x allows network administrators to choose between two types of Access Control used
on the Switch, which are:
1. Port-Based Access Control – This method requires only one user to be authenticated per port by a remote RADIUS
server to allow the remaining users on the same port access to the network.
2. MAC-Based Access Control – Using this method, the Switch will automatically learn up to three MAC addresses
by port and set them in a list. Each MAC address must be authenticated by the Switch using a remote RADIUS
server before being allowed access to the Network.
Port-Based Network Access Control
The original intent behind the development of 802.1x was to leverage the characteristics of point-to-point in LANs. Any
single LAN segment in such an infrastructures has no more than two devices attached to it, one of which is a Bridge Port.
The Bridge Port detects events that indicate the attachment of an active device at the remote end of the link, or an active
device becoming inactive. These events can be used to control the authorization state of the Port and initiate the process of
authenticating the attached device if the Port is unauthorized. This is the Port-Based Network Access Control.
