About

ip packet is the name of a data unit for the network layer (level 3 of the OSI model) (ie IP).

TCP/IP sends a TCP packet known as segment:

• which is carried in one or more IP packets by the IP protocol
• which are each carried in one or more Ethernet packet known as frame by the ethernet

Example

Example of a DNS query IP Packet ¹⁾

where you can see:

• The Mac header
• The Ipv4 header
• The Udp header
• And finally, the payload (in our case, a DNS query)

Forge

Packets can be forged / dynamically created (including source IP addresses).

Structure

IP packets consist of:

• a header for addressing and routing,
• and a payload for user data.

Path

Flow of network packets in an operating system. There are two distinct layers in the packet path:

• IP firewall
• network stack

Type

• Ipv4
• Ipv6
• …