TCP/IP: IP packet
IP packet contains a 20 bytes (at least) header and the data for the transport layer
IP header contains:
- IP addresses for the source and the destination
- the length of the data
- a 8 bits identifier for the protocol of data carried (TCP, UDP, ICMP,…)
- a 8 bits TTL (Time To Live) field decremented by each device to avoid loops
- a CRC to control the integrity of the header
- ...