On a hub, you can see other systems’ unicast traffic as long as the interface you are connected to operates at the same speed as the other interfaces. This is very different from hubs and wireless networks.

This is because switches forward unicast traffic only to their intended destinations. In Promiscuous Mode, you can the see the traffic destined to and from your system, including other systems’ multicast and broadcast traffic however, you cannot view any of the unicast traffic from the other systems connected to the switch. If you are on a wired network, there’s a high chance you’re connected directly to a switch located on a small subnet or broadcast domain.

In “Promiscuous Mode,” Wireshark captures all the traffic on the network that we are currently associated with. This makes sense in the world of networking and it’s also favorable from a security perspective. Other systems’ unicast traffic, if received by our network interface card, is not processed because the traffic is not specifically addressed to our system. Whether we’re using wireless or wired network interfaces cards, our system only process the unicast, multicast, and broadcast traffic destined to our system. Windows systems, on the other hand, don’t come with libpcap and must therefore download and install “WinPcap,” which stands for “Windows Packet Capture.” Promiscuous Mode and Monitor Mode UNIX/Linux systems come with “libpcap,” which stands for “Promiscuous Library Capture.” This API is used to grab packets right off the network interface card. Wireshark uses a pcap (packet capture) API to capture packets. Before understanding how Wireshark works, it definitely helps to understand the OSI model, so be sure to familiarize yourself with how computers communicate with each other. If you’re already familiar with tcpdump or Tshark, then Wireshark will be simple to understand.

As a packet analyzer, Wireshark’s functionality includes network troubleshooting, packet capture analysis, real-time network traffic observation, examining security problems, protocol implementation debugging, and reconnaissance. Wireshark is a GUI, cross-platform, open-source protocol and packet analyzer available for Microsoft Windows, Linux, Mac OS, BSD, Solaris, and some other Unix-like operating systems.

Wireshark usage in cyber secuirty