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.

2 ways to check DNS PTR Record in Linux

DNS PRT record is short for pointer record. It is one of the common Domain Name System (DNS) records. It resolves an IP address to a domain or hostname. It is also called DNS reverse record. The following commands can…

Check DNS A Record with Examples

DNS A record maps a domain name to the IP address (Version 4) of the server hosting the domain. The “A” stands for “address”. DNS A record indicates the IP address of a given domain. DNS A record is the…

Best and Fastest DNS Servers in 2023

A DNS, or Domain Name Server, is what helps translate human-friendly URLs into computer-friendly IP addresses. This is what enables our devices to connect to the internet and access the content we want to see. When people change their DNS,…

10 Useful Examples of Openssl S_client Command

The OpenSSL s_client command is a helpful test client for troubleshooting remote SSL or TLS connections. This post covers various examples of testing SSL connections with different ciphers, TLS versions, and SSL server certificate analysis. OpenSSL s_client connect openssl s_client…

Check SSL TLS cipher suites in Linux

An SSL cipher, or an SSL cipher suite, is a set of algorithms or a set of instructions/steps that helps to establish a secure connection between two entities. SSL cipher suites determine the method through which a secure connection will…