A packet header is a section of a packet that contains metadata and control information necessary for the proper routing and delivery of the packet across a network. The header typically includes the following fields:
- Source Address: The address of the device that sent the packet.
- Destination Address: The address of the device intended to receive the packet.
- Protocol Information: Indicates the protocol used (e.g., TCP, UDP, ICMP).
- Sequence Number: Used to order packets correctly when they arrive out of sequence.
- Checksum: A value used for error-checking to ensure data integrity.
- Time to Live (TTL): Limits the packet's lifespan to prevent it from circulating indefinitely.
The header is crucial for network devices to process and route the packet correctly to its destination.
