PureStream PureLink VIP-NET-M28A Media Hub, User Manual

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VIP-NET-M28A Network Switch - USER MANUAL
VERSION 1.0
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.
The maximum number of supplicants that can be attached to a
port can be limited using the Port Security Limit Control
functionality.
MAC-based Auth.
Unlike port-based 802.1X, MAC-based authentication is not a
standard, but merely a best-practices method adopted by the
industry. In MAC-based authentication, users are called clients,
and the switch acts as the supplicant on behalf of clients. The
initial frame (any kind of frame) sent by a client is snooped by
the switch, which in turn uses the client's MAC address as both
username and password in the subsequent EAP exchange with
the RADIUS server. The 6-byte MAC address is converted to a
string in the following form "xx-xx-xx-xx-xx-xx", that is, a dash
(-) is used as separator between the lower-cased hexadecimal
digits. The switch only supports the MD5-Challenge
authentication method, so the RADIUS server must be
configured accordingly.
When authentication is complete, the RADIUS server sends a
success or failure indication, which in turn causes the switch to
open up or block traffic for that particular client, using the Port
Security module. Only then will frames from the client be
forwarded on the switch. There are no EAPOL frames involved
in this authentication, and therefore, MAC-based authentication
has nothing to do with the 802.1X standard.
The advantage of MAC-based authentication over port-based
802.1X is that several clients can be connected to the same port
(e.g. through a 3rd party switch or a hub) and still require
individual authentication, and that the clients don't need special
supplicant software to authenticate. The advantage of MAC-
based authentication over 802.1X-based authentication is that
the clients do not need special supplicant software to
authenticate. The disadvantage is that MAC addresses can be
spoofed by malicious users - equipment whose MAC address
is a valid RADIUS user can be used by anyone. Also, only the
MD5-Challenge method is supported. The maximum number of
clients that can be attached to a port can be limited using the
Port Security Limit Control functionality.
Port State
The current state of the port. It can undertake one of the
following values:
Globally Disabled : NAS is globally disabled.