Packet Data

Packet data, or 'packets', refers to pieces of data that are formatted for internet transfer. Packets contain the data itself, as well as information about the data, such as where it came from.

This packet information is used by firewalls to determine whether a given packet abides by the security 'rule sets' that firewalls follow - including features such as the source, destination and content. Different levels of the network may perceive these features differently - so various types of firewalls exist which are able to read the packet data at different levels. As packet data travels through the network, it is reformatted several times. If the packets data proves at all suspicious, a firewall will stop the packet from entering the guarded network.