Linux

AirPiConsole part two

Welcome back to AirPiConsole blog post, this is part two. If you read part one and followed the configuration steps you should now have a fully working Raspberry Pi Zero W connected to your WiFi network. You should also be able to connect via Bluetooth to get a console connection without knowing the IP address of the Raspi. Now it’s time to move on and start to actually connect to the serial ports.

AirPiConsole part one

As a network engineer I spend a lot of time with my laptop connected via serial cable to various devices. Physical serial connection is needed for initial device setup and sometimes per customer’s security policy I can’t access the network, so I can only use out-of-band management. I also configure many devices at staging lab that I call the “Theory room” because you know, in theory everything works ;-)

Simple Cisco switch inventory with bash and snmp

Scripts, usually I write some because I don’t like repetitive tasks and I’m lazy, meaning I prefer automation over useless hard work. Don’t know where I found this quote but I like it: Don't spend your time doing work a well-trained monkey could do. Today’s request was quite simple: get model and serial number from a bunch of Cisco switches. I now NEDI, Observium and LibreNMS can do that but I preferred to write a quick script I could use as a one shot tool instead of a complete software solution.

AWK and Cisco WLC

When you see an hacker movie you see people typing on the keyboard very fast. Actually the toughest the hacker is the faster he types very long commands and all of them work the first time. Want to impress friends and colleagues? Type on the hackertyper ;-) More experienced network engineers, as I learn during my CCIE studies, type in a [text language=“editor”][/text]2 then copy/paste on the CLI. This approach make easier to spot typos, faster to reuse configuration snippets and to change portions of configuration and more.

Docker join the dots

This post is part of a series about Docker, including: Docker Introduction Docker: Install software inside a container Docker Volumes Docker Networking - bridge container to host NIC We started with the basics and moved on with adding software, using volumes and then bridging a container to the network. As a said I’m neither a developer or a system administrator, I work as Network Engineer so I’m not the main target for Docker but I found it very useful for a specific need and now it’s time to join the dots.

Docker networking bridge to host NIC

This post is part of a series about Docker, including: Docker Introduction Docker: Install software inside a container Docker Volumes Today we’ll see Docker networking with a very specific target in mind: bridge container to the host network. This isn’t supposed to be the way of work of containers: a container should be created to run a single application so container networking, from the point of view of a Network Engineer, is essentialy a Port Address Translation with a firewall exception.

Docker Volumes

In the last post we saw that any filesystem change inside a docker container is lost if not commited to the image. What if we want to share data between containers? We can use Docker’s Data Volumes and Data Volume Containers. Data Volumes or Data Volume Containers? Data Volumes feature allows us to mount a local directory from the host inside a container. That looks good but somehow it breaks the concept of isolation between host and container.

Docker Install software inside a container

In the first post of this series we left with a running Ubuntu 15.04 container. Now it’s time to install software inside the container. A container is “stateless”, meaning any file change inside a container is lost when the container is closed, including software installations. Install software To install software inside a container any method supported for the Linux distribution is fine. I usually install Python 2.7, iftop, htop, tmux so let’s run a container:

Introduction to Docker

Docker and more generic Linux containers technology are a hot topic these days. The website says “for developers and sysadmins”, I am neither of the two but I can still find some useful applications for containers as a Network Engineer. Let’s start from the basics. Install docker and first run We can apt-get to install docker on Ubuntu Linux: apt-get install docker.io Now start docker service: service docker start That was easy.

Debian Administrator's Handbook

A nice and free manual to manage Debian: Accessible to all, this book teaches the essentials to anyone who wants to become an effective and independent Debian GNU/Linux administrator. http://debian-handbook.info/

Tomahawk IPS Test Tool

Tomahawk is a command line tool for testing network-based intrusion prevention systems (NIPS). The concept is simple, you can download virus,attacks,exploit pcaps from many sources and save them on the Tomahawk machine. To test an IPS you need tree network interfaces: one for management, one to send traffic and one to receive. If the attack sent on the interface is received on the other interface the IPS didn’t filtered it.