what is technical difference in hub and switch

[ali usman]

any one can explain the major difference in hub and switch.why we prefer to use switch instead of hub.if i have to select one switch out of four what is criteria that i use to perform my selection.
thanks for every one who reply

 

[Point Break]

The Difference between a switch and a hub is simple but makes a large difference. First off a hub is a layer 1 device, a switch being layer 2. Hubs simply take all imformation recieved, and forward it out all ports of the hub. Only the computer that the data is meant for will accept the data the rest will discard the data. Hubs are a "dumb" device, and since all this data is being shot out all ports all the time they tend to be prone to data collisions. Hubs also cannot be configured. Switches are more of an intelligent device, they make forwarding decisions. They dont just forward data out all ports in hopes that the person its intended for recieves it. Switches use CAM, which in CAM is a list of the computers MAC addresses and which port they are out, so when data goes into the switch, the switch looks at its switching table and forwards the data only out the port the destination computer is at. Because of this point to point type data forwarding and full-duplex wireing switches rarely have data collisions and create less traffic. Switches may also be configured through the console port. Hubs are a bit faster since they dont stop to make decisions and are better if you only a have few devices on a hub, but switches make up for their millisecond delay for decision if you have many computers on a line.


Bottom line, Switches are newer, better, and more efficent and I agree are a better choice of use over hubs.

 

[IBMan]

couldnt've said it better myself.

 

[Ethereal_Dragon]

As far as 'picking' a switch, any UNMANAGED SOHO type switch would work. I say UNMANAGED, but that is just a guess, because they are cheaper than managed switches. They are just plug and play. I was under the assumption that if you had to ask this question, you didn't need specific advanced features you would find on a managed switch.

If you could provide us with a list of the 4 switches you are looking at, we can give you a suggestion..
To be honest, I haven't seen a hub for sale in a LONNG time... sure there are used stores, and ebay, but I haven't seen one NIB in a commercial store in quite some time. Switch have pretty much replaced hubs, as a typical 10/100 switch (unmanaged) can be found for under $40.

 

[IBMan]

those unmanaged switches can hardly be considered a switch, they say they're switches but i doubt they have a MAC addr table or much of any of the other tables.

 

[ibarrere]

it depends on what kind you get. I was curious about the same thing, so I hacked one open and it definitely had cams... However, the cams are flushed once they have like 5 mac addresses, so they clog up the network with arp packets and the like. They're pretty useless

 

[Law]

Hubs are still very useful device, in an Intrusion Detection environment using a switch wouldn't work but using a hub the IDS can detect all traffic. Hubs may be fading away but they should not disappear completely, they are still useful in my book.

 

[Point Break]

Yes I agree Hubs still are very useful, I am a computer technician and at my work I use hubs. In each room we have three computers all hooked into a hub, then the line runs to the main switch, but a hub is cheap and simple and works fine with few computers on the line.

 

[C0RR0SIVE]

Hubs in my opinion are great if you have a good sized network and want to expand a part of it to another part of the building with out running more cables or buying another switch... Just plug the hub into the switch and the other computers into the hub..... If it is a small expansion ^_^