Page 788 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

hoc mode. Ad hoc mode means that any two wireless networking

devices, including two wireless network interface cards (NICs), can
communicate without a centralized control authority. Infrastructure
mode means that a wireless access point is required, wireless NICs on
systems can’t interact directly, and the restrictions of the wireless
access point for wireless network access are enforced.

Within the infrastructure mode concept are several variations,
including stand-alone, wired extension, enterprise extended, and

bridge. A stand-alone mode infrastructure occurs when there is a
wireless access point connecting wireless clients to each other but not
to any wired resources. The wireless access point serves as a wireless
hub exclusively. A wired extension mode infrastructure occurs when
the wireless access point acts as a connection point to link the wireless
clients to the wired network. An enterprise extended mode
infrastructure occurs when multiple wireless access points (WAPs) are
used to connect a large physical area to the same wired network. Each

wireless access point will use the same extended service set identifier
(ESSID) so clients can roam the area while maintaining network
connectivity, even while their wireless NICs change associations from
one wireless access point to another. A bridge mode infrastructure
occurs when a wireless connection is used to link two wired networks.

This often uses dedicated wireless bridges and is used when wired
bridges are inconvenient, such as when linking networks between
floors or buildings.

The term SSID (which stands for service set identifier) is

typically misused to indicate the name of a wireless network.
Technically there are two types of SSIDs, namely extended service
set identifier (ESSID) and basic service set identifier (BSSID). An
ESSID is the name of a wireless network when a wireless base
station or WAP is used (i.e., infrastructure mode). Independent

service set identifier (ISSID) is the name of a wireless network
when in ad hoc or peer-to-peer mode (i.e., when a base station or
WAP is not used). However, when operating in infrastructure
mode, the BSSID is the MAC address of the base station hosting