Wireshark

Wireshark lets you see what’s happening on your network at a microscopic level and is the standard across many commercial and non-profit enterprises, government agencies, and educational institutions. Wireshark has a rich feature set which includes the following: - Deep inspection of hundreds of protocols, with more being added all the time - Live capture and offline analysis - Standard three-pane packet browser - Multi-platform: Runs on Windows, Linux, macOS, Solaris, FreeBSD, NetBSD, and many others - Captured network data can be browsed via a GUI, or via the TTY-mode TShark utility - The most powerful display filters in the industry - Rich VoIP analysis - Read/write many different capture file formats: tcpdump (libpcap), Pcap NG, Catapult DCT2000, Cisco Secure IDS iplog, Microsoft Network Monitor, Network General Sniffer® (compressed and uncompressed), Sniffer® Pro, and NetXray®, Network Instruments Observer, NetScreen snoop, Novell LANalyzer, RADCOM WAN/LAN Analyzer, Shomiti/Finisar Surveyor, Tektronix K12xx, Visual Networks Visual UpTime, WildPackets EtherPeek/TokenPeek/AiroPeek, and many others - Capture files compressed with gzip can be decompressed on the fly - Live data can be read from Ethernet, IEEE 802.11, PPP/HDLC, ATM, Bluetooth, USB, Token Ring, Frame Relay, FDDI, and others (depending on your platform) - Decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2 - Coloring rules can be applied to the packet list for quick, intuitive analysis - Output can be exported to XML, PostScript®, CSV, or plain text