Replace Linux Cooked Header with Ethernet:if you capture on the "Any" interface on Linux you'll most likely end up with a trace file that contains pseudo headers instead of Ethernet headers. A new Ethernet header will be crafted, using as much information from the cooked header as possible, and written to the output file instead of the original header.

Replace Ethertype: in some cases you may want to force a specific Ethertype to be used instead of the original. If the value set in the "original" field is detected, it will be replaced with the replacement value.