Network Equipment Explained
NIC
Network Interface Card
This is the card inside of your computer that allows you to connect to the network.Repeater
A Repeater is a device that extends the distance that a network segment can be effective. Repeaters are the most simple network device.Hub
A Hub, or a Multi-Port Repeater, is a device which connects several computers together. It simply connects the Transmit of one computer to the Recieve of all the others. When you use a Hub, divide your toal bandwidth by the number of ports that are in use.Bridge
A Bridge is similar to a Repeator in that it connects two network segments together. However, it is smarter than a Repeater. The Bridge looks at the MAC addresses in packets and only passes packets that need to be passed. A Bridge will still pass Broadcast packets, but it does reduce network traffic.Switch
The Switch is a Multi-Port Bridge.A Switch keeps a record of what MAC Addresses are on what ports by monitoring the From Addresses in packets. In doing this, it can reduce network traffic, by directing packets to only the ports they goto. This also allows you to communicate in full dupex between computers. This effectively doubles your network bandwidth.
The MAC Address is a Non-Logical address. That means the addresses are essentually random. MAC Addresses are burned into the ROM chips of Network cards. MAC Addresses can not be changed, without changing the Network Interface Card
Router
A Router is much smarter than a Switch. A Switch can only sort commnication packets that it knows where they goes, but a Router can sort packets that it does not know where they go. A Router is smart enough to know the best guess of where the data should go. The Router sorts data by IP Address, or IPX Address.IP and IPX addresses are logical addresses. A logical address is one that is set by an Administrator, and has reason to it. The addresses are split up into Networks. As a result, a Router does have to know the destination, because it knows if it sends it to te right network, the packet will make it to the correct host.
Routers can also do functions like DHCP (Dynamic Host Control Protocl), NAT (Network Address Translation), and Access Control. These features can make the network operation much easier, and much more secure.
