Archive for the ‘System Administrator Articles’ Category

Reverse SSH tunnel or connecting to computer behind NAT router

Introduction Few days ago I encountered a problem. How do you connect to a computer behind NAT router? Any NAT router is also a firewall. Sometimes you do have access to firewall configuration and can set up port forwarding. Yet often it is complicated and even impossible. Common situation is when you want to connect [...]

SMP affinity and proper interrupt handling in Linux

Introduction Hardware interrupts has always been expensive. Somehow these small pieces of software consume so much CPU power and hardware and software engineers has always been trying to change this state of affairs. Some significant progress has been made. Still hardware interrupts consume lots of CPU power. You will rarely see effects of interrupt handling [...]

Useful Linux Networking Commands

This article describes most useful Linux networking commands, as simple as it sounds. The truth is that I am writing this article more for myself. I am rarely doing complex networking configurations. As a result, when I have to configure something, I often forget commands and their syntax. Often it takes hours to find out [...]