Where is Tcpdump installed on Linux?

It comes with many flavors of Linux. To find out, type which tcpdump in your terminal. On CentOS, it’s at /usr/sbin/tcpdump. If it’s not installed, you can install it using sudo yum install -y tcpdump or via the available packager manager on your system like apt-get.

How do I check tcpdump?

tcpdump also gives us a option to save captured packets in a file for future analysis. It saves the file in a pcap format, that can be viewed by tcpdump command or a open source GUI based tool called Wireshark (Network Protocol Analyzier) that reads tcpdump pcap format files.