Re-Introduction to PCAP Replay and GopherCAP

A while back we introduced GopherCAP, a simple tool written in Golang that leverages Google's GoPacket library for advanced packet replay. We were challenged by a special dataset that traditional tools simply could not handle. 

More than a year has passed since we posted that initial introduction article in which we emphasized PCAP replay as the first GopherCAP use case. The GopherCAP command-line tool was implemented as a Go binary that incorporates multiple subcommands. Some are meant to be used in tandem, such as map and replay commands which were introduced in our previous blog post. Others are meant to tackle specific use cases where traditional tooling falls short. This post introduces one such subcommand - filter.