We feature technical articles across the entire IT spectrum - CCNA networking, security, operating systems, cloud, and programming.

How do I add a Space to Selected Lines within VIM?

Introduction Most likey there will be a time (for one reason or another) where you need to insert a number of spaces to a set of lines within a text file.Within this short article we will show you how via the use of VIM. Steps 1. Within VIM select blockwise visual mode, by pressing CTRL-V.2. … Read more

What is RESTCONF?

Introduction Following on from our previous article around NETCONF and YANG, we will look at the RESTCONF protocol. As per RFC 8040 (RESTCONF Protocol), the IETF describes RESTCONF as, “an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).” Protocol … Read more

An Introduction to NETCONF/YANG

TL;DR NETCONF/YANG provides a standardized way to programmatically update and modify the configuration of a network device. To break this down further. YANG is the modelling language that describes the configuration changes. Whereas  NETCONF is the protocol that applies the changes to the relevant datastore (i.e running, saved etc) upon the device. Introduction Let us start … Read more

How to Configure a Cisco CSR using NETCONF/YANG

Introduction Within this tutorial we will use NETCONF and YANG to configure an interface upon a Cisco CSR router using a combination of Python and the BASH CLI. Furthermore we will use 2 main tools – Pyang and Pyangbind. Before we start lets have a quick overview on what these tools do, Pyang is a YANG … Read more

A Brief Explanation of Kernel Space and User Space

Introduction Within the Linux kernel, knowing how memory is separated is extremely important. As knowing what programs reside where, and the requirement on the system to move memory from one place to another, can provide a huge insight into the performance, or lack of, within a system. And when it comes to the world of … Read more

vSRX on an Isolated Network – How do I Provision via Cloud-Init?

Background Introduced within the Junos OS Release – 15.1X49-D100 – the vSRX now comes with cloud-init. As per Junipers configuration guide, … the cloud-init package (version 0.7x) comes pre-installed in the vSRX image to help simplify configuring new vSRX instances operating in an OpenStack environment according to a specified user-data file. Cloud-init is performed during … Read more

Troubleshooting Connectivity to the Neutron Metadata Proxy

  Introduction After troubleshooting a recent issue with accessing meta services from a guest instance, and jumping through the various steps within the path, I soon realised – this would make for a great article. Issue So first of all let’s look at the issue. The issue was pretty basic. Quite simply I was unable … Read more

A Guide to Network Function Virtualization (NFV)

Introduction NFV is a term that has been around for a few years now. As vendors and the open source communities look to drive the adoption of NFV, a wave of new acronyms and buzzwords are spreading through the industry. Within this article we will look into the various NFV components (such as standards, platforms, … Read more

OpenStack Partitioning – Regions, Availability Zones and Host Aggregates

An OpenStack Cloud can be divided into three main hierarchical zones – Regions, Availability Zones and Host Aggregates. Regions A Region is full OpenStack deployment, including its own API endpoints, networks and compute resources[1], excluding the Keystone and Horizon. Each Region shares a single set of Keystone and Horizon services. Host Aggregates Host Aggregates are logical … Read more