IP Packet structure 4-bit 8-bit Version Header Type of Service 16-bit Total Length(Bytes) Length (TOS) 3-bit 16-bit Identification Flag specifies how to interpret the 8-bit Time to start of the Payload, which is Live (TTL) 8-bit Protocol the header of a transport Protocol such as tcP or UDP 32-bit Source P Address 32-bit Destination IP Address Options (if any) PayloadIP Packet Structure 4-bit Version 4-bit Header Length 8-bit Typeof Service (TOS) 16-bit Total Length (Bytes) 16-bit Identification 3-bit Flags 13-bit Fragment Offset 16-bit Header Checksum 8-bit Time to Live (TTL) 8-bit Protocol 32-bit Source IP Address 32-bit Destination IP Address Options (if any) Specifies how to interpret the start of the Payload, which is the header of a Transport Protocol such as TCP or UDP Payload