A packet sniffer itself is passive. It observes messages being
sent and received by applications and protocols running on
your computer, but never sends packets itself [10]. Similarly,
received packets are never explicitly addressed to the packet
sniffer. Instead, a packet sniffer receives a copy of packets that
are sent or received from and by application and protocols
executing on your machine. Network professionals also use
Wireshark to troubleshoot networking problems.