Which of the following controls would allow a company to reduce the exposure of sensitive systems from
unmanaged devices on internal networks?
IEEE 802.1X (also known as Dot1x) is an IEEE Standard for Port-based Network Access Control (PNAC). It is
part of the IEEE 802.1 group of networking protocols. It provides an authentication mechanism to devices
wishing to attach to a LAN or WLAN.
802.1X authentication involves three parties: a supplicant, an authenticator, and an authentication server. The
supplicant is a client device (such as a laptop) that wishes to attach to the LAN/WLAN – though the term
‘supplicant’ is also used interchangeably to refer to the software running on the client that provides credentials
to the authenticator. The authenticator is a network device, such as an Ethernet switch or wireless access point;
and the authentication server is typically a host running software supporting the RADIUS and EAP protocols.
The authenticator acts like a security guard to a protected network. The supplicant (i.e., client device) is not
allowed access through the authenticator to the protected side of the network until the supplicant’s identity has
been validated and authorized. An analogy to this is providing a valid visa at the airport’s arrival immigration
before being allowed to enter the country. With 802.1X port-based authentication, the supplicant provides
credentials, such as user name/password or digital certificate, to the authenticator, and the authenticator
forwards the credentials to the authentication server for verification. If the authentication server determines the
credentials are valid, the supplicant (client device) is allowed to access resources located on the protected side
of the network.