Here I will keep networking related posts.

BGP Hijacking - What is it and how to prevent it?

Wed, 09/30/2020 - 17:04

BGP stands for Border Gateway Protocol, more commonly known as the system that keeps the internet (and by definition, routing) working correctly. Sometimes misconfigurations (Like accidentally announcing a wrong prefix) can break the internet. In this blog post, I will explain BGP Hijacking and how to prevent it. Primarily for people without network experience.

Generating IPv6 PTR records from a Bind9 Zonefile using Bash

Sun, 08/02/2020 - 15:05

The following script takes a Bind9 zonefile, gets all AAAA records from it and generated PTR records based on them.

What you need to do:

  1. Edit the Zone header in the script.
  2. Run the script with ./ /path/to/

This will output the zones on STDOUT. If you want to save this to a zonefile, you can use this example: ./ /path/to/ > /etc/bind/

DigitalOcean Kubernetes with Static IPv4

Sun, 05/03/2020 - 16:57

Thanks to the new VPC functionality in DigitalOcean can be used to provide Kubernetes with a static external IPv4. This can be handy in cases where you need to deal with IP whitelists, for example, if you use your Kubernetes cluster as a CI building tool. However, this requires some config setup and a privileged pod running on each node to automatically update the routes. This article will help guide you through the setup.