Alejandro Acosta Alamo wrote: > > Hello, > I understand the differences between Cut-through and Store & > Forward. My > question is: How do you decide with method to use?, in whch > situation have > you change the switching method?. > > Thanks > > Alejandro Acosta > > A lot of switches support only one method, so you don't have a choice. If you do have a choice, the decision is based on the number of errors on your network. Cut-through doesn't do any error checking and in fact forwards frames that have a bad CRC or are too short. Ethernet says that frames must be at least 64 bytes. Anything less is considered a fragment and is illegal. Cut-through forwards fragments that have an entire destination address that can be looked up to get a port number.
If your switch connects many shared networks, then CRC errors and fragments due to collisions are normal. But why waste bandwidth forwarding these to other ports on the LAN? In this case, you might want to go with store-and-forward which does not forward errored frames or fragments. If your switch connects single devices all using full-duplex, then it's unlikely that you are experiencing many CRC or fragments. So, cut-through makes the most sense. Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=48322&t=48316 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
