My guess is that your sniffer sees them as 60 bytes, since most sniffers leave don;t count the CRC which is 4 bytes. Most of these are ARP packets.
""Alejandro Acosta Alamo"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hello again, > Priscilla, you have said that an ethernet frame must be at least 64 bytes, > right?. I have just placed an sniffer on my LAN and I found over 3000 out of > 15.000 packets. Does this mean that 20% of those packets are illegal? > > Thanks > > Alejandro Acosta > > ----- Original Message ----- > From: "Priscilla Oppenheimer" > To: > Sent: Monday, July 08, 2002 1:08 PM > Subject: RE: Cut-through vs Store & Forward [7:48316] > > > > 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=48537&t=48316 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
