A switch, keeps a record of the MAC addresses of all the

devices connected to it. With this information, a switch

can identify which system is sitting on which port. So when

a frame is received, it knows exactly which port to send it

to, which significantly increases network response times.

And, unlike a Hub, a 10/100Mbps switch will allocate a full

10/100Mbps to each of its ports. So regardless of the

number of PCs transmitting, users will always have access

to the maximum amount of bandwidth. It's for these reasons

why a switch is considered to be a much better choice then

a hub.

Routers are completely different creatures. Where a hub or

switch is concerned with transmitting frames, a router's

job, as its name implies, is to route packets to other

networks until that packet ultimately reaches its

destination. One of the key features of a packet is that it

not only contains data, but the destination address of

where it's going.

A router is typically connected to at least two networks,

commonly two LANs or WANs or a LAN and its ISP's network

(ex. your pc or workgroup and EarthLink). Routers are

located at gateways, the places where two or more networks

connect. Using headers and forwarding tables, routers

determine the best path for forwarding the packets. Routers

use protocols such as ICMP to communicate with each other

and configure the best route between any two hosts.

A router will typically include a 4-to-8 port Ethernet

switch (or hub) and a Network Address Translator (NAT). In

addition, they usually include a Dynamic Host Configuration

Protocol (DHCP) server, Domain Name Service (DNS) proxy

server and a hardware firewall to protect the Local Area

Network (LAN) from malicious intrusion from the Internet.