Page 818 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

is known as a store-and-forward device. Bridges operate at OSI layer
2. Systems on either side of a bridge are part of the same broadcast

domain but are in different collision domains.

Switches Rather than using a hub, you might consider using a switch,
or intelligent hub. Switches know the addresses of the systems
connected on each outbound port. Instead of repeating traffic on every
outbound port, a switch repeats traffic only out of the port on which
the destination is known to exist. Switches offer greater efficiency for

traffic delivery, create separate collision domains, and improve the
overall throughput of data. Switches can also create separate broadcast
domains when used to create VLANs. In such configurations,
broadcasts are allowed within a single VLAN but not allowed to cross
unhindered from one VLAN to another. Switches operate primarily at
OSI layer 2. When switches have additional features, such as routing,
they can operate at OSI layer 3 as well (such as when routing between
VLANs). Systems on either side of a switch operating at layer 2 are

part of the same broadcast domain but are in different collision
domains. Systems on either side of a switch operating at layer 3 are
part of different broadcast domains and different collision domains.
Switches are used to connect network segments that use the same
protocol.

Routers Routers are used to control traffic flow on networks and are

often used to connect similar networks and control traffic flow
between the two. They can function using statically defined routing
tables, or they can employ a dynamic routing system. There are
numerous dynamic routing protocols, such as RIP, OSPF, and BGP.
Routers operate at OSI layer 3. Systems on either side of a router are
part of different broadcast domains and different collision domains.

Routers are used to connect network segments that use the same
protocol.

Brouters Brouters are combination devices comprising a router and
a bridge. A brouter attempts to route first, but if that fails, it defaults to
bridging. Thus, a brouter operates primarily at layer 3 but can operate
at layer 2 when necessary. Systems on either side of a brouter
operating at layer 3 are part of different broadcast domains and

different collision domains. Systems on either side of a brouter