Question about how switches react to data from a hub.

[Sukhoi]

Say I have a switch as a LAN backbone, and then each room has a hub for the computers in the room.

If computer A is sending data to computer B in the same room, the hub will send the data to every port that is currently connected, correct? Since one of the ports is connected to the switch, what will the switch do since the data goes to the same port on the switch that it just came from? Will it ignore the data, or will it send it back? If it sends it back, then won't computer B actually be getting 2 coppies of everything computer A sends?

 

[spidey07]

No the switch will not send the frame back out of the port. A switch works by building a bridge table that associates MAC addresss to ports.

Switch receives frame on port 1
Switch looks in bridge table for destination mac address.
Switch finds DSTMAC on port 1.
Switch drops frame.

Broadcasts and multicast received on any port are flooded to all ports of the switch. I've seen your previous post. I don't believe in hubs or shared media. There is no place for them in today's networks. switch everything.

spidey

 

[Sukhoi]

Cool, thanks. I was just curious...I don't have any big setup like that.



<< I've seen your previous post. >>



Which one do you mean...I don't post a whole lot in this forum. Are you talking about the one where I wanted to know if I should get the Linksys 5 port switch rather than 5 port 10/100 hub?

 

[spidey07]

whoops, wasn't you. just your reply.

Just preaching the gospel of switched networking