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Antaira Technologies - Industrial Ethernet Switches
LNX-2012G-SFP Series User Manual V1.0
67
are used in the communication between the supplicant and
the switch. If more than one supplicant is connected to a
port, the one that comes first when the port's link comes up
will be the first one considered. If that supplicant doesn't
provide valid credentials within a certain amount of time,
another supplicant will get a chance. Once a supplicant is
successfully authenticated, only that supplicant will be
allowed access. This is the most secure of all the supported
modes. In this mode, the Port Security module is used to
secure a supplicant's MAC address once successfully
authenticated.
Multi 802.1X
In port-based 802.1X authentication, once a supplicant is
successfully authenticated on a port, the whole port is
opened for network traffic. This allows other clients
connected to the port (for instance through a hub) to piggy-
back on the successfully authenticated client and get
network
access
even
though
they
really
aren't
authenticated. To overcome this security breach, use the
Multi 802.1X variant.
Multi 802.1X is really not an IEEE standard, but features
many of the same characteristics as does port-based
802.1X. Multi 802.1X is - like Single 802.1X - not an IEEE
standard, but a variant that features many of the same
characteristics. In Multi 802.1X, one or more supplicants
can get authenticated on the same port at the same time.
Each supplicant is authenticated individually and secured in
the MAC table using the Port Security module.
In Multi 802.1X it is not possible to use the multicast BPDU
MAC address as destination MAC address for EAPOL
frames sent from the switch towards the supplicant, since
that would cause all supplicants attached to the port to reply
to requests sent from the switch. Instead, the switch uses
the supplicant's MAC address, which is obtained from the
first EAPOL Start or EAPOL Response Identity frame sent
by the supplicant. An exception to this is when no
supplicants are attached. In this case, the switch sends