Protocol analyzers (also known as sniffers or network monitors) are used to seize packets in a raw format when they are transmitted over the network. Earlier, Windows Vista operating system had a built-in protocol analyzer called Network Monitor, but it is not used nowadays. The reason is that network monitor tool captures only those packets that are sourced from the computers on which the tool is running. However, you can use the protocol analyzer in other operating systems by simply downloading it. The marketable protocol analyzer tools, such as Wireshark, can capture any packets because they are set in Network Interface Card (NIC) that processes all packets that it receives.
Protocol analyzers also determine the type of traffic in your network. Packet sniffer can capture and show all packets that are used in establishing a network connection.