On 4/12/2022 10:12 AM, Paul Koning wrote:

On Apr 12, 2022, at 9:56 AM, Todd Goodman via cctalk <cctalk@classiccmp.org> 
wrote:
...
The big difference in my mind between bridge and switch is:

* Switches learn what port given MACs are on and only sends unicast
   traffic destined for that MAC address on that port and not all
* Bridges send unicast traffic to all ports
Absolutely not.  The only standard device that forwards unicast to all ports is 
the repeater.  I don't know of any packet forwarding device that sends unicast 
traffic to all ports; certainly no such thing can be found in any standard.

Learning was introduced by DEC in the DECbridge 100 (along with spanning tree); 
IEEE later standardized this, with some small mods, in 802.1d.

        paul

You snipped the part where I said except for ports that should not receive the traffic due to blocked ports from the Spanning Tree Protocol in 802.1d and that if that fails you end up with a broadcast storm.

Well, I didn't mention STP in 802.1d specifically because I thought it was obvious.

Bridges were useful even after switches arrived to allow monitoring of traffic on any port of the bridge.  It was useful before switches got port mirroring and even after as it didn't require any configuration.

Todd



Reply via email to