TCPDUMP is a Linux tool which at times is not suitable for use with Gaia.
Specifically, it can use a noticeable amount of CPU.
Check Point created a tool which works better with Gaia OS: CPPCAP
'CPPCAP' is a traffic capture tool which provides the most relevant outputs and is similar to Tcpdump.
The tool is adjusted to Gaia operating system yet requires installation of an applicable RPM.
You can download this tool for R77.30, R80.10, and R80.20 and get more details here: Running TCPDUMP causes high CPU usage