Bits 0-7

Bits 8-15

Bits 16-23 Bits 24-31

IP Header (20 bytes)

Version/IHL

Type of service

Length

Identification

flags and offset

Time To Live (TTL)

Protocol

Checksum

Source IP address

Destination IP address

ICMP Header (8 bytes)

Type of message

Codę

Checksum

Header Data

ICMP Payload (optional)

Payload Data