hub or switch?

[JCROCCO]

What is the basic difference between a hub or switch?

I know what a hub does, how is it different than a switch?

 

[WobbleWobble]

Hub broadcasts packets to all the ports where as a switch has a port to port connection.

That's the basic difference. If you need more than 2 different simultaneous data transfers, get a switch as it'll be generally faster. You would choose a hub because it's cheaper or because you need to sniff network packets more easily.

Edit: Reworded

 

[gunrunnerjohn]

A hub broadcasts everything that it receives out all ports. A switch "learns" which port each MAC address is connected to and only directs addressed traffic to the port that the addressed machine is attached to. Broadcasts that have no specific address are handled the same with either a switch or a hub.

There is basically little reason to use a hub most of the time, since a switch will use the network bandwidth more efficiently. Nowadays, simple hubs and switches are pretty much the same price for the same number of ports.

 

[JCROCCO]

Can a switch be used on a PTP network?

Is it better/faster/both to use a switch rather than a 100baseT hub?

When should you use a hub only or a switch only?

 

[petersjf]

Everything said here was basically correct, though alot of generalizing took place. A hub is a collision domain. Basically, all packets are mearly mirrored to every port and a procedure is implemented to detect collision and packet loss, as a result of the collision. On a network with several computers, these collisions could begin to take up a noticiable portion of the available bandwidth.

Switches, in there most basic form, slighty delay(milliseconds) traffic and provides that no collisions take place. Thus splitting a single collision domain into many collision domains. This makes a switch, a broadcast domain.

Many switches offer more features. Switches traditionally have always worked in the Data Link Layer(Layer 2) of the OSI model. This layer has to do with the MAC addresses on network adapters(among other things). Many newer switches will form a table of MAC addresses in order to be more efficient with unicasts.

Switches first began getting into the domain of routers(layer 3) when cisco implimented access rule lists on its switches. The switches were then able to read the part of the packet encapsilation that forwarded the source network address. This did not allow for routing based upon ip or ipx address though. Just port security.

The newest switches in the high end market are capable of routing by Layer 3. They retain the name of switch because they are generally purpose built to provide switching capabilities at the network edge.

 

[p0lar]

I feel that they retain the name of a 'switch' to keep many 'routers' from becoming obsolete, ergo Cisco Catalyst 5500 w/RSM.

These are VERY inexpensive now-a-daze, but for ethernet routing, would easily make any of the 2600/3600 'routers' look like very poor performers for the expense. Cisco could easily make several of their product lines obsolete - i.e. VPN Concentrator, PIX, types of routers, by incorporating only a FEW more features into the Catalyst series. To some degree, they have, and some lines are. Of course, there will always be a place in the world for the 12000 series and the like, but it will be nice when L3 switches (routers) are the norm and not the exception. I believe Cisco has really started to think along this mentality with the relatively new 3550 line (both SMI and EMI). I use several of those at the office and have thus far been quite impressed over the previous 1900/2900/2950 lines. It was probably around 1997 - 1998 when the first L3 switches started hitting the scenes. Even Madge/Olicom had a L3 fast ethernet switch in '99, back in their days of ATM grandeur.

Anyway, I digress, we now return you back to your regularly scheduled programming.