SSL Certificate with SubjectAlternativeName (SAN)

If you want to create an SSL certificate for multiple subdomains, you could either use a wildcard certificate like * or you could use an SSL certificate with SubjectAlternativeName (SAN). For example, if you create an SSL certificate with SubjectAlternativeName (SAN) like this: CN: SAN:, In my understanding it was one main […]

Docker Reverse Proxy

When it comes to (simple) web applications, then most of the time Docker is a perfect fit. However, as you begin to migrate your applications into Docker containers, you might ask yourself how to forward all the requests to the different containers. A Docker Reverse Proxy can help!

sysctl tuning on Linux

While most Linux Kernels nowadays come with nice sysctl defaults, there’s always room for improvement. Some parameters can be used for performance tuning, others can be critical for security hardening. What is sysctl? sysctl is an interface to view and dynamically change parameters in Linux and other *NIX operating systems. In Linux, most of the dynamic Kernel settings can be […]

TCP connection states

TCP is the abbreviation for Transmission Control Protocol. It is one of the core protocols in the internet protocol suite and provides a reliable protocol to communicate in computer networks. Nearly every Internet-connected device “talks” TCP and the whole Internet relies on it.