At 06:05 PM 3/13/02, Brian Lodwick wrote: >""PING"" wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > I have follwoing questions: > > > > Q1: When all the ports are in BLOCKing mode at start on switch, > > how the initial broadcasts are then forwarded in a network so that > > switches can learn about each other via BPDUs? > >It is blocking data traffic not protocol updates (BDPUs)
A blocked port also doesn't send BPDUs. But it does hear and process them. Also, during startup, a port transitions out of blocking into listening relatively quickly. In the listening state, it does send BPDUs. > > > > Q2: When a switch breaks the collision domains, then what is the > > point of using Fragment Free method to avoid collisions? > >Fragment Free tries its best. Collisions can still occur. The difference >between the mothods is the amount of the packet that is read before it is >forwarded. True. Cut-through starts forwarding ASAP. Fragment Free waits until at least 64 bytes are received. Store and Forward waits for the entire frame. >If you want to have the best chance of never having a collision >use Store and Forward. Not true. The forwarding method doesn't affect the chances of having a collision. Fragment Free simply means don't forward a fragment (which usually was the result of a collision that already occured). > > /N ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38159&t=38137 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
