What is a Network Sniffer?

Posted by Carlos on June 7th, 2019

A network sniffer is a software tool or piece of hardware which is used to monitor network traffic.  Hardware implementations of a packet analyzer are employed by network administrators or security professionals working with large networks.

There are various software network sniffing tools available that make it possible for anyone to monitor network traffic. The same tool can be used for constructive or malicious purposes depending on who is running the application. Network admins and hackers both have the same tools but with very different purposes. Wireless network sniffers are used to monitoring and potentially get entry into WiFi networks which are becoming more prevalent every day.

How Does a Network Sniffer Work?

A network sniffer takes advantage of the process in which data is transmitted across a network. Networks send data in different packets to maintain data integrity and avoid network congestion. When files or emails are sent they are broken into smaller packets before being sent to their destination. The information included with each transmission includes:

• The destination address
• Number of packets being transmitted
• Reassembly order of the packets
• The Source address

When the data arrives at its destination, the message’s headers and footers are stripped off, and the data is reconstructed. Networks and computers discard all messages that are not intended for them via a network filter.

A network packet sniffer operates by intercepting and logging the network traffic. The software analyzes the traffic and converts it to a user-friendly format. Depending on who is using the packet analyzer, the data provided by the tool can be used in a variety of ways.