On Thu, Sep 02, 2010 at 06:38:52PM -0300, Luiz Henrique Ozaki wrote: > Some MAC into switch A is comunicating with a MAC in switch B, when MAC at > switch B is shutdown, the switch will send that packets to all ports in > switch B and if the switch C is connected to switch B, the packets will go > thought all ports in C too and switch D is connected to C, D to E = > broadcast to all switches ! When a port is disconnected, the switch know > that the port state changed and make the MAC address entry goes incomplete > for that MAC and no packets are sent, maybe an arp request but not the > packet broadcast.
The switch will indeed start broadcasting all packets to an unlearned MAC. If the sender spews them out at an uncontrolled rate, then you will waste a lot of bandwidth across your entire subnet. But reasonable senders will not do that (and TCP/IP is reasonable in this sense). > As far as I know, the switch have MAC address table relation MACs to ports > and those packets are sent only when this relation is valid always or try to > do so. Seems a primary function since without this a "broadcast of death" > can be easy to make. > > As you said, I should assume a switch flooding broadcast packets and if the > switch doesn't have that check, all your network in the same VLAN will crash > since that packet of death will go all over the switches. I don't know what you mean by "packet of death" here. Flooding a unicast packet across your subnet won't cause hosts any consternation. They won't even see it unless their NICs are in promiscuous mode. _______________________________________________ discuss mailing list [email protected] http://openvswitch.org/mailman/listinfo/discuss_openvswitch.org
