ARP populates pkt's network header with an ARP header found in pkt.Data.

ICMPv4 populates the packet buffer's transport header with an ICMPv4 header, if present.

ICMPv6 populates the packet buffer's transport header with an ICMPv4 header, if present.

IPv4 parses an IPv4 packet found in pkt.Data and populates pkt's network header with the IPv4 header.

IPv6 parses an IPv6 packet found in pkt.Data and populates pkt's network header with the IPv6 header.

TCP parses a TCP packet found in pkt.Data and populates pkt's transport header with the TCP header.

UDP parses a UDP packet found in pkt.Data and populates pkt's transport header with the UDP header.