What are network packets?
Packet is data unit of TCP/IP communication transferring, which operates on the second layer (network layer) and the third layer (transport layer) of OSI. The framework of a packet is very complicated, but primarily, it is composed of destination IP, source IP, data, etc. Destination IP is the IP address of receiver where this packet will reach; source IP is the IP address of sender where the packet is from; and data is the content of this packet. Only those computers installed TCP/IP protocols can communicate with each other owing to such framework of packet, in fact, when we communicate via network which bases on TCP/IP, what transferred through network are packets. To keep network secure, network administrators need to know what packets are active on network by analyzing packets and find out the problems. In a word, comprehending and parsing packets are essential to network security.
