Document memset, and fix it so that it fills the full size of the packet buffer, not all bar the last position.
Document memset, and fix it so that it fills the full size of the packet buffer, not all bar the last position.

neographophobic/BlueCube,neographophobic/BlueCube,neographophobic/BlueCube,neographophobic/BlueCube,neographophobic/BlueCube,neographophobic/BlueCube