Here is the part where Wireshark filters come into play. From this tons of information maybe you are interested in only a minor part like BGP traffic or a certain IP source and destination. The problem is that if you capture the packets traveling through a backbone router you will end having huge file ( yes, even up to 1G if you capture long enough) and a lot packets details in it. Wireshark is extremely useful when it comes to network troubleshooting as it capture the packets and you can have a detail look into them checking if everything is OK in parameters, message, format and so on. – Decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2 – 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 platfrom) – Capture files compressed with gzip can be decompressed on the fly – 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 – Captured network data can be browsed via a GUI, or via the TTY-mode TShark utility – Multi-platform: Runs on Windows, Linux, OS X, Solaris, FreeBSD, NetBSD, and many others – Deep inspection of hundreds of protocols, with more being added all the time It is the continuation of a project that started in 1998. Wireshark development thrives thanks to the contributions of networking experts across the globe.

Wireshark is one of the world’s foremost network protocol analyzer, and is the de facto standard across many industries and educational institutions. When it comes to network sniffing or packet capturing or whatever you want to call it, I believe that the name Wireshark (formerly Ethereal) ring a bell in your head.

Sometime the problem is right there, you can see it and it’s easy to fix, but in other cases you’ll have to put an eye in the packets that are traveling through it and search deeper for the solution. Now and then, especially when you expect less, the network crashes or encounter an issue and then you had to troubleshoot.

Wireshark filter source