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NS3503-16P-4C User Manual
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4.9 Security
This section is to control the access of the Managed Switch, including the user access and management
control.
The Security Page contains links to the following main topics:
802.1x
Radius Server
Server
AAA
Access
Management Access Method
DHCP Snooping
Dynamic ARP Inspection
IP Source Guard
Port Security
DoS
Strom Control
4.9.1 802.1X
Overview of 802.1X (Port-based) Authentication
In the 802.1X-world, the user is called the supplicant, the switch is the authenticator, and the RADIUS
server is the authentication server. The switch acts as the man-in-the-middle, forwarding requests and
responses between the supplicant and the authentication server. Frames sent between the supplicant
and the switch are special 802.1X frames, known as
EAPOL (EAP over LANs)
frames. EAPOL frames
encapsulate
EAP PDUs (RFC3748)
. Frames sent between the switch and the RADIUS server are
RADIUS packets. RADIUS packets also encapsulate EAP PDUs together with other attributes like the
switch's IP address, name, and the supplicant's port number on the switch. EAP is very flexible, in that it
allows for different authentication methods, like
MD5-Challenge
,
PEAP
, and
TLS
. The important thing is
that the authenticator (the switch) doesn't need to know which authentication method the supplicant and
the authentication server are using, or how many information exchange frames are needed for a
particular method. The switch simply encapsulates the EAP part of the frame into the relevant type
(EAPOL or RADIUS) and forwards it.
