The IP packet header contains information about the packet such as the version and header length, type of service, total length, identification, flags, fragment offset, time to live, protocol, header checksum, source and destination IP addresses, and any options. This header information is used to route the packet to its destination.

1. IP PACKET HEADER 4-bit version 4-bit Header len 8-bit type of service 16-bit total length (in bytes) 16-bit identification 3-bit flags 13-bit fragment offset 8-bit time to live (TTL) 8-bit protocol 16-bit header checksum 32-bit source IP address 32-bit destination IP address Options (if any) data 0 31 15 16 20 bytes