ABSTRACT
Here's how the two headers stack up. The Version field is unchanged between the two protocols. IPv4's Internet Header Length, Type of Service, Identification, Flags, Fragment Offset, and Header Checksum fields are dropped. The Total Length, Time to Live (TTL), and Protocol fields have new names and slightly redefined functions in IPv6. The Option field in IPv4 has been removed from the header and repurposed as an extension capability. Lastly, IPv6 includes two new fields: Class and Flow Label. The following section examines each of the header fields in an IPv6 packet.
