2010/1/3 Rob Malpass <l...@getiton.myzen.co.uk>: > > ----- Original Message ----- > From: "James Courtier-Dutton" <james.dut...@gmail.com> > To: "Hampshire LUG Discussion List" <hampshire@mailman.lug.org.uk> > Sent: Sunday, January 03, 2010 3:09 PM > Subject: Re: [Hampshire] NAS devices and MTU > > > >>Do you know the difference between a hub and a switch? Replacing hubs >>with switches will greatly reduce the amount of traffic on each >>network link. > > Hubs work at one speed, switches work at the most appropriate speed - that's > the > difference isn't it? >
For a hub, when one host sends a packet, all hosts on the network receive it. For a Layer 2 switch, when one host sends a packet, only those hosts that should receive it get it. a) broadcast packets go to all PCs. b) multicast packets go to only the multicast listeners (if IGMP snooping is working on the switch) c) unicast packets only go the the specific destination PC. For a Layer 3 switch, this behaves more like a multi port router. File transfers use the "unicast" packets, so you can see how a switch can handle file transfers much better than a hub. When purchasing a switch, beware of cheap ones. You need to take into account the PPS (packets per second) value for the switch. Kind Regards James -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --------------------------------------------------------------
