Hi, when I ran this "show int counters errors", I have a bunch of "giants" on my interfaces. Can someone explain why I might have these giant frames? And how would I go about to recreate it in a lab environment?
Without knowing anything about your topology/layer2/layer3 protocols it's difficult to say why you may be getting them. Often it can be related to trunking on a link (ISL or 802.1q) or MPLS label addition.
Have a look at this document and then come back if you have further questions.
