Would you agree with this statement? A classroom is not the same as a school.
Ah ha. I got you. What about a one-room school? That's the sort of logic that you are using. A network that uses just hubs is like the one-room school. It is a single collision (bandwidth) domain. It is also a single broadcast domain, but that's just because they are living in the dark ages like the one-room school and haven't upgraded to a switched environment. A switch subdivides collision domains. But it does not subdivide broadcast domains. You need a router for that, as you know. An Ethernet collision domain is all devices in a network connected via a single cable or hubs. Every device hears every other device's transmission. If two devices send at the same time, a collision results. These device compete for bandwidth. They are in the same bandwidth domain. These devices are also in the same broadcast domain as each other. In addition, these devices are in the same broadcast domain as all devices in their switched network. Devices on the other side of the switch are not in the same collision (bandwidth) domain as these devices however. They don't hear every transmission. They just hear broadcasts because the switch forwards them. They don't compete for bandwidth. Devices on opposite sides of the switch can transmit at the same time and it's not a collision. I think I said it better with the school analogy. ;-) Priscilla At 08:25 PM 3/27/02, John Green wrote: >but please consider this diagram: > > -------------------ROUTER-------------------- > | | | | | | | | > A B C D E F G H > >A,B,C,D are hosts in say network 10.10.10.0 /24 >E,F,G,H are hosts in say network 10.10.9.0 /24 > >say Host A sends a broadcast, then it will be heard by >the network on left side and not on right side as >ROUTER will not allow any broadcast through. >and the hosts in network on left are connected to a >HUB and network on right to another separate HUB. > >Now the collision domain and broadcast domain for the >network on left side is same. is it not ? > > >--- Priscilla Oppenheimer wrote: > > At 01:02 PM 3/27/02, John Green wrote: > > >so Broadcast domains and Bandwidth domains are the > > >same ? > > > > Of course not. We said that bandwidth and collision > > domains are the same on Ethernet. > > > > > (i guess so) > > > > > >For Ethernet broadcast and collision domains are > > the > > >same. right ? > > > > Of course not. You may be confused because some > > people use "broadcast" when > > talking about sending Ethernet at the physical > > layer. A coaxial cable is > > sometimes called a broadcast medium because the bits > > radiate out from the > > sender and reach all senders on the cable. It's an > > unfortunate use of the > > term that has been carried into generic discussions > > of Ethernet, despite > > the demise of coaxial-cable based Ethernet. > > > > Broadcast means a frame addressed to > > FF:FF:FF:FF:FF:FF. Switches forward > > these frames to all ports. They forward unicasts > > only to the correct port > > once they learn the location of destinations. A hub, > > on the other hand, > > forwards all bits without regards for the > > destination address. > > > > This is networking 101. Do you know about the CCNA > > study list? You should > > join that list. > > > > Priscilla > > > > > > >--- Priscilla Oppenheimer wrote: > > > > A bandwidth domain is an area of a network where > > all > > > > devices can hear each > > > > other's transmissions. A collision domain is a > > type > > > > of bandwidth domain, > > > > but it's specific to Ethernet. > > > > > > > > I think people started using the term "collision > > > > domain" first and then > > > > someone said, "yes, but that doesn't apply to > > token > > > > ring which doesn't have > > > > collisions!" so some marketing engineer came up > > with > > > > the term "bandwidth > > > > domain." ;-) > > > > > > > > Priscilla > > > > > > > > > > > > >__________________________________________________ > > >Do You Yahoo!? > > >Yahoo! Movies - coverage of the 74th Academy > > Awards. > > >http://movies.yahoo.com/ > > ________________________ > > > > Priscilla Oppenheimer > > http://www.priscilla.com >[EMAIL PROTECTED] > > >__________________________________________________ >Do You Yahoo!? >Yahoo! Movies - coverage of the 74th Academy Awards. >http://movies.yahoo.com/ ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39851&t=38887 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
