ORiNG IGS-9168GP series, Руководство пользователя

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IGS-9168GP User’s Manual
ORing Industrial Networking Corp 123
piggy-back on the successfully authenticated client and get network
access even though they are not authenticated individually. To
overcome this security breach, use the Single 802.1X variant.
Single 802.1X is not yet an IEEE standard, but features many of the
same characteristics as port-based 802.1X. In Single 802.1X, at most
one supplicant can get authenticated on the port at a time. Normal
EAPOL frames are used in the communications between the supplicant
and the switch. If more than one supplicant are connected to a port, the
one that comes first when the port's link is connected will be the first one
considered. If that supplicant does not provide valid credentials within a
certain amount of time, the chance will be given to another supplicant.
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.
b. 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 are not authenticated individually. To
overcome this security breach, use the Multi 802.1X variant.
Multi 802.1X is not yet an IEEE standard, but features many of the same
characteristics as port-based 802.1X. In Multi 802.1X, one or more
supplicants can be 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 the destination MAC address for EAPOL frames sent from
the switch to 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 EAPOL Request Identity frames using the
BPDU multicast MAC address as destination - to wake up any
supplicants that might be on the port.