Transition Networks
S4224 Web User Guide
33558 Rev. C
Page 431 of 669
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 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 on the following form "
xx-xx-xx-xx-xx-xx
" or "
xx.xx.xx.xx.xx.xx
" or
"
xxxxxxxxxxxx
" (x is a hexadecimal digit). The switch only supports the
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 maximum number of clients that can be attached to a port can be limited using the Port Security
Limit Control functionality.
Port State
Displays the current state of the port. It can be one of the following values:
Globally Disabled
:
NAS is globally disabled at
Configuration
>
Security
>
Network
>
NAS
>
System
Configuration
>
Mode
=
Disabled
.
Link Down
:
NAS is globally enabled, but there is no link on the port.
Authorized
:
The port is in Force Authorized or a single-supplicant mode and the supplicant is
authorized.
Unauthorized
:
The port is in Force Unauthorized or a single-supplicant mode and the supplicant is
not successfully authorized by the RADIUS server.
X Auth/Y Unauth
:
The port is in a multi-supplicant mode. Currently,
X
clients are authorized and
Y
are unauthorized.
QoS Class
The QoS class assigned by the RADIUS server. The field is blank if no QoS class is assigned.
Port VLAN ID
The VLAN ID that NAS has put the port in. The field is blank, if the Port VLAN ID is not overridden by
NAS.
If the VLAN ID is assigned by the RADIUS server,
"(RADIUS-assigned)"
is appended to the
VLAN ID.
If the port is moved to the Guest VLAN,
"(Guest)"
is appended to the VLAN ID.
