If the backplane or fabric of the switch isn't designed properly A->C and B->D can't necessarily happen at the same time. The backplane has to have enough capacity for that. With only four ports, it's probably not a problem. On a switch with dozens or hundreds of ports, it is a very real problem.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Gary Thornock Sent: Thursday, 04 September, 2003 10:00 To: BYU Unix Users Group Subject: RE: [uug] switching If A, B, and C all send to D simultaneously then yes, a collision still happens. You can't avoid the collision in that case. The benefit of a switch is that A can send to C at the same time that B sends to D, without causing a collision. On a hub, *any* two simultaneous transmissions will collide, even if they don't have a host in common. The other benefit to a switch is that it offers dedicated, full-duplex bandwidth for each port, rather than shared, half-duplex bandwidth for all ports (what you get from a hub). > -----Original Message----- > From: Michael Ryan Byrd [mailto:[EMAIL PROTECTED] > Sent: Thursday, September 04, 2003 09:51 > To: BYU Unix Users Group > Subject: [uug] switching > > > ok, so an ethernet hub creates one big collision domain, that is to > say, that all the hosts plugged into the hub have the possibility of > colliding (transmitting at the same time) with each other. > > A switch is supposed to create separate collision domains (AFAIK.) > But what if we have a four port switch(A,B,C,D) and A,B and C all > try to send a packet to D at the same time. Would a collision > happen? > > Ryan ____________________ BYU Unix Users Group http://uug.byu.edu/ ___________________________________________________________________ List Info: http://uug.byu.edu/cgi-bin/mailman/listinfo/uug-list ____________________ BYU Unix Users Group http://uug.byu.edu/ ___________________________________________________________________ List Info: http://uug.byu.edu/cgi-bin/mailman/listinfo/uug-list
