tshark - Dump and analyze network traffic

TShark is a network protocol analyzer. It lets you capture packet data from a live network, or read packets from a previously saved capture file, either printing a decoded form of those packets to the standard output or writing the packets to a file. TShark's native capture file format is libpcap format, which is also the format used by tcpdump and various other tools.

Without any options set, TShark will work much like tcpdump. It will use the pcap library to capture traffic from the first available network interface and displays a summary line on stdout for each received packet.

TShark is able to detect, read and write the same capture files that are supported by Wireshark. The input file doesn't need a specific filename extension; the file format and an optional gzip compression will be automatically detected.