For those of use who are not IT savvy, what's the difference between a hub and a switch and a router? I have a Linksys "router" which, I believe, I could use to connect 2 or up to 4 computers in a network. I use it for its firewall capability. Could you, or someone, please explain what these words--hub, switch, router--actually mean?
A hub is the simplest of the three. A hub merely simulates a single wire that all machines are connected to and share bandwidth from - either 10 or 100 Mbit/s, and only in half duplex mode. That is a machine may only transmit or receive at any one time. Full duplex mode - the ability to simultaneously transmit or receive - requires a switch. Only one machine can transmit on the "wire" at a time. Other machines must wait. If a machine transmits while another machine is transmitting the packets of data will collide - a collision in technical terminology. When a collision occurs the packets involved must be resent. This obviously slows down your connection. A (layer 2) switch is a "smarter" device and offers more bandwidth through "virtual" connections. When two machines wish to communicate the switch configures a dedicated connection between the two. Many of these connections can be created on the same switch between many different machines. The number of connections that can be maintained is limited by the speed and bandwidth available on the "backplane" of the switch. The backplane consists of the internal "mesh" that connects all ports on the switch and the processor or processors in the switch (some switches have seperate processors per port, some use a single processor). Each connection to the switch can be negotiated at either 10, 100, or 1000 Mbit/s and at half or full duplex modes (with some exceptions. Some older switches only worked at 10 Mbit/s or only in half duplex mode). A router is used to connect two different networks or network topologies. For example connecting your internal LAN to your ISP's lan requires a router. Connecting your machines to your LAN requires a hub or switch. As you know based on the device you own these devices can be configured in the same box. Some advanced switches - called "layer 3" or higher switches - can actually perform routing. In many enterprises many routers have been replaced by these types of switches. That's obviously the mile high view, and I've over simplified in a lot of places, but hopefully that was of some help. -- John LeMay KC2KTH Senior Enterprise Consultant NJMC | http://www.njmc.com | Phone 732-557-4848 Specializing in Microsoft and Unix based solutions