Protocol Dissector Tool for Deoding in Band Packet Header on A Switch

Serviceability of networks is a vital part of network management which helps in isolating faults and triaging network issues. Packet analyzers help in identifying faults, security threats and other implementation flaws in the networking software by capturing network traffic and analyzing it. Packet analyzing is heavily based on protocols which need to be decoded from the raw format and presented to the user in an understandable format. In this work, a Command Line Interface based protocol dissector tool has been developed which runs on the operating system of a switch and performs packet decoding by capturing in band packets flowing between control and data plane of the switch. The tool also provides support for packet filtering in order to only capture packets which the user needs. Existing packet dissectors run on Wireshark in the form of Lua plugins. However, in this work the implementation of the entire system is based on C. Some of the public protocols decoded by this tool involve IPv4, IPv6, UDP, TCP, ARP, ICMP and so on. Also, this tool supports decoding of private protocols as well.