because of their high-quality router products, great selection, and fantastic
service. Routers, by default, break up a
ment. Breaking up a broadcast domain is important because when a host or
server sends a network broadcast, every device on the network must read
and process that broadcast--unless you've got a router. When the router's
interface receives this broadcast, it can respond by basically saying "Thanks,
but no thanks," and discard the broadcast without forwarding it on to
other networks. Even though routers are known for breaking up broad-
cast domains by default, it's important to remember that they also break
up collision domains as well.
is to make a LAN work better--to optimize its performance--providing more
bandwidth for the LAN's users. And switches don't forward packets to other
networks like routers do. Instead, they only "switch" frames from one port to
another within the switched network. (Theoretically, you don't know what
frames and packets are yet, but don't worry: I'll tell you all about them later
in this chapter, I promise!)
packet on a network segment, forcing every other device on that same
segment to pay attention to it. At the same time, a different device tries to
transmit, leading to a collision, after which both devices must retransmit,
one at a time. Not very efficient! This situation is typically found in a hub
environment where each host segment connects to a hub that represents only
one collision domain and only one broadcast domain. By contrast, each and
every port on a switch represents its own collision domain.