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.

Check SSL Connection with OpenSSL S_client Command

SSL (Secure Sockets Layer) connection is a connection that provides secure communications on the Internet for such things as web browsing, e-mail, instant messaging, and other data transfers. Although SSL was replaced by an updated protocol called TLS (Transport Layer…

How to Fix Unable to get Local Issuer Certificate

“Unable to get Local Issuer Certificate” is a common SSL certificate error. It is related to the incomplete certificate chain such as (most commonly) missing the intermediate certificate or missing the root certificate authority (CA) certificate in its trusted certificate…

what is an epic in jira?

An epic is often a larger user story that is broken down into smaller stories in order to be worked on. The important thing to note about epics is that they aren’t just an agile tool. Teams of all work…

Understanding SSL certificates

Server certificates are known as SSL/TLS certificates. It verifies and validates the identity of the certificate holder or applicant before authenticating it. It also establishes an encrypted communication channel and switches the protocol to HTTPS once installed on the server.…

Check SSL Certificate Chain with OpenSSL Examples

certificate chain is an ordered list of certificates, containing an SSL/TLS Certificate and Certificate Authority (CA) Certificates, that enable the receiver to verify that the sender and all CA’s are trustworthy. The chain or path begins with the SSL/TLS certificate,…

Exploring Tcpdump Filters with Examples

Let’s dive into the fascinating world of tcpdump! It’s a command-line packet analyzer that allows you to capture and inspect network traffic. Think of it as a microscope for your network. We’ll break down how to use its filtering capabilities…