Both bridges and switches learn the port to use to reach a MAC destination. If they haven't learned it yet, they flood the frame out all ports except the originating port.
Jean Andrews has written some superb books on PC technology. I have a book by her called "A+ Guide to Managing and Maintaining Your PC" that is excellent. But she should stick to her day job. She doesn't seem to know networking. Her description of bridges and switches is false, as you say. Maybe she could write some fiction in her spare time. ;-) The only real difference between bridges and switches is in their architectures, both hardware and software. Switches have more ports. Switches have a more complex switching fabric that lets them forward multiple frames at once. They are often implemented as a crossbar. Think of a bridge as being like a literal bridge across a river or whatever. Think of a switch as being like a complicated Japanese Pachinko machine! Regarding the difference between a MAC table and CAM table: They are just different names for the same thing. Priscilla At 10:57 AM 5/24/02, Kevin Jones wrote: >Ok. I found the source of the information. I would like to here your >feedback on this. > >Course Technology * Thompson Learning, i-Net+ Guide to Internet >Technologies, Jean Andrews, p. 443-445 > >"What is the difference between a bridge and a switch? The main difference >is how they work. A bridge broadcasts data to one or more LANs while a >switch knows which LAN a packet should be sent to." > >"In order to determine which network the packet should be sent to, the >bridge creates and maintains a routing table that lists the computers on >each LAN. A separate table is kept for each LAN. When a data packet >reaches the bridge, the bridge looks at the packet's destination address, >then searches the routing table for the originating LAN, looking for the >destination address of the data packet. If it finds the address in this >routing table, it drops the packet, knowing that the packet will have >already reached its destination, because it was broadcast to all nodes on >the LAN by the LAN's hub." > >"If the bridge did not find the destination address in the routing table for >that LAN, it broadcasts the packet to all nodes on all LANs it is connected >to except the LAN that the packet came from. Therefore, a bridge only makes >a single decision, 'Is this packet destined for a node on its own network?' >If the answer is 'No,', then the bridge simply broadcasts it to all other >LANs." > >"A switch, on the other hand, deosn not work by sending broadcast messages. >Just like bridges, switches also keep tables of all the MAC addresses of all >the devices connected to the switch. They use these tables to determine >which path to use when sending packets." > >"... Using the destination address in the header of the packet, the switch >would refer to its tables and determine the LAN to which the packet is >addressed. The switch then forwards the packet to the proper LAN, rather >than broadcasting the packet to all the LANs." > > From this thread, and from past experience, shall we assume that this is >completely false? While i-Net plus only skims the surface of network >technology, this book (like many others) seems to have a lot of errors. >Another example would be the fact that the MAC tables are referred to as >routing tables. > >That reminds me, what is the difference between a MAC table and a CAM table? > >Kevin ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=44974&t=44649 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
