Wireshark's most powerful feature is its vast array of display filters (over 316000 fields in 3000 protocols as of version 4.4.8). They let you drill down to the exact traffic you want to see and are the basis of many of Wireshark's other features, such as the coloring rules. This is a reference. For general help using display filters, please see the wireshark-filter manual page or the User's Guid