David Cao

David Cao

David is a Cloud & DevOps Enthusiast. He has years of experience as a Linux engineer. He had working experience in AMD, EMC. He likes Linux, Python, bash, and more. He is a technical blogger and a Software Engineer. He enjoys sharing his learning and contributing to open-source.

Exploring ICMP Port Number with Example

There is no port number associated with ICMP packets. ICMP uses types and codes. The type and code combination identifies the specific message being received. The network software itself interprets all ICMP messages. Today we are going to show you…

Filtering SSH Packets with Tcpdump on Port 22

Tcpdump is a command-line packet analysis tool. We can use tcpdump to capture ssh traffic to troubleshoot connection issues and look for potential security issues on a network.   What is SSH? SSH, which stands for Secure Shell, is a…

Using Tcpdump to Filter DNS Packets

Tcpdump is a very powerful Linux command to capture DNS packets. DNS is short for Domain Name System. It is a database that links meaningful names to a specific IP address. We can use tcpdump to filter DNS packets to…

Capture Ping Packets With Tcpdump

ICMP is a network layer protocol used by network devices to diagnose network communication issues. Tcpdump command on Linux can be used to capture network packets. We can use the following examples to capture ICMP and ICMPv6 packets with tcpdump…