Authentication Process - D-Link DES-1228/ME User Manual

Client
The Client is simply the endstation that wishes to gain access to the LAN or switch services. All endstations must be running
software that is compliant with the 802.1X protocol. For users running Windows XP, that software is included within the
operating system. All other users are required to attain 802.1X client software from an outside source. The Client will request
access to the LAN and or Switch through EAPOL packets and, in turn will respond to requests from the Switch.

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.
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. Host-Based Access Control – Using this method, the Switch will automatically learn up to sixteen 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.
Understanding 802.1X Port-based and Host-based Access Control
The original intent behind the development of 802.1X was to leverage the characteristics of point-to-point in LANs. As any single
LAN segment in such infrastructures has no more than two devices attached to it, one of which is a Bridge Port. The Bridge Port
DES-1228/ME Layer 2 Fast Ethernet Managed Switch
Figure 10- 16. The Client
Figure 10- 17. The 802.1X Authentication Process
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