Ever wondered what's the difference between a Hub a switch and a router?
Here's the quick and dirty on it..
A hub is nothing more than a multi-port repeater, what this means is it gets signals in on
any given port cleans the signal up and sends it out all ports. It doesn't concern itself
with addressing it just recieves and retransmits signals. These old gentlemen of lan technology usually
operates at the 10/100 Mb range. A hub creates a shared media, meaning all users have accesss at the same
time, this introduces the oppurtunity for collisions, which is bad, bad, bad.. Another thing to note on
hubs is that they will only operate as fast as the slowest node connected to the hub.. If you have 4
computers hooked to a hub and they have 10/100 Mb cards and introduce a 5th pc with a 10 Mb card you just
turned your 100 Mb network into a 10 Mb network.. Son-ova, that's gonna leave a mark!!!
Hubs operate at the "Physical layer" of the OSI model..
A switch on the other hand concerns itself with mac addresses and builds MAC tables which allows for
virtual circuits.. When a switch is turned on for the 1st time it has to learn the mac addresses of all
the nodes that are connected to it, it stores these addresses in it's MAC table and uses this table for
forwarding frames. When a switch gets a frame that has an unrecognized mac address it stores in it's MAC
table, if a switch gets a frame with a destination address it does not recognize the it and sends it out
all ports until it finds the destination port and at that point it creates (siwtches on) the virtual circuit.
Each and every NIC has it's own unique MAC address, that is hard coded into the NIC.
A switch micro-segments your lan, which means makes it smaller, which means virtually no collisions which is
good, good, good. Gigabit switches are now on the market which is 10 to 100 times faster than a Hub network.
Switches operate at the "Data-link Layer" of the OSI model..
A Router performs the functions of a switch along with the added function of routing packets. A rotuer makes
it's routing decisions based on IP Addresses. This is where the Internet lives and breathes.. A router has
routing tables based on IP Addresses and gets periodic updates from neighboring routers. Compared to switches Routers
are slow, usually operating at the speed of WAN links. A full T1 is only 1.5 Mbps which when compared to the speed of
a fully switched lan operating a 100 Mbps or full duplex lan operating at 200 Mbps is pathectically slow..
Rotuers operate at the "Network layer" of the OSI model..
What is the OSI model?
The OSI(Open Systems Interconnect) Model is a collection of standards and protocols
that make it possible for different types of hardware and software to be able to communicate.
More on this later..