[Richard Brodie <leogah@xxxxxxxxxxx>]

> Moreover, I don't understand how ethernet dissector can find if there 
is padding or not.

You can only do this with '802.3' style frames where the type/length 
field contains a length.
In the typical case, where the type/length field identifies a type, it's 
all passed up to the next
layer which will have to work it out for itself.

Richard Brodie.