Understanding VLAN terminology – Access Trunk Native Tagged Untagged
Ever so often I myself have searched around for the exact difference between all of the different terms associated with VLAN's (Virtual Local Area Networks) and I'm sure a lot of people out there do the same. There's so much out there explaining these terms but it gets confusing when everything is virtualized. How does networking work in a virtualized host where the operating system networking stack provide virtual network functions such as a virtual switch?
I will start out by stating that networking works the same way it is expected to work in the physical world with wires and hardware boxes that switch or route traffic. To understand what these terms mean you need to first understand how VLANs work. VLAN segregation can happen on a IP range basis, on a port to port basis on the switch, based on protocol, based on mac addresses or just based on some other higher layer abstractions. The most common implementation is however port based and I will go ahead by explaining these terms with respect to this premise. Also some of these terms are specifically defined by Cisco switches and have then on gone to become popular in network design vocabulary Continue reading
I will start out by stating that networking works the same way it is expected to work in the physical world with wires and hardware boxes that switch or route traffic. To understand what these terms mean you need to first understand how VLANs work. VLAN segregation can happen on a IP range basis, on a port to port basis on the switch, based on protocol, based on mac addresses or just based on some other higher layer abstractions. The most common implementation is however port based and I will go ahead by explaining these terms with respect to this premise. Also some of these terms are specifically defined by Cisco switches and have then on gone to become popular in network design vocabulary Continue reading
Contain Your Unikernels!
After DockerCon EU in Barcelona several people asked me: “Is this for real?”. Yes it is, and today we are releasing the code for the entire “Unikernels, meet Docker!” demo on GitHub.
To get started, clone the DockerConEU2015-demo repository and follow the instructions in README.md. You will need a Linux host with Docker and KVM installed.
Apart from the MySQL, Nginx and PHP with Nibbleblog unikernels shown in the demo, the repository also contains some simpler examples to get you started that we did not have time to show live in the short time-slot. There’s also an in-progress MirageOS/KVM port, so stay tuned for a future post on that.
Presented as a ‘cool hack’ in the closing session of the conference, this demo is just a taste of what is possible. Next, I’m going to work with the wider unikernel and Docker developer community on a production quality version of this demo. The goal is to make unikernel technology easily accessible to as many developers as possible!
Personally, I would like to thank Amir Chaudhry, Justin Cormack, Anil Madhavapeddy, Richard Mortier, Mindy Preston and Jeremy Yallop for helping me put the demo Continue reading
Slack has transformed the way teams communicate & they now plan to go IPO!
Having kept my pensive empty for quite some time now its time for a kick start. And what better way to start than to talk about Slack - A communication tool that has revolutionized intra-team, inter-team interactions and day to day messaging.
After the dot com burst and the difficult times of 2009 technology industry is now at a point where innovation is ever more flourishing with new companies announcing their birth and the more mature ones going through multiple rounds of funding, acquisitions and IPOs. Slack is one such company that has gone from a small startup to a multi-billion dollar venture and now in the process of going IPO (TechCrunch). The customer first approach with product re-engineering from customer feedback has yet again proved to be one of the most important ingredients to being successful along with laser sharp focus areas. Slack's growth trajectory is clearly exponential, one that I'm sure any founder would love to have in their annual revenue reports.
Being an engineer in a startup, I am lucky enough to be using this communication tool daily. Having used other paid tools like Cisco Jabber to the free ones like Google Hangouts, Skype and Continue reading
Unikernels, meet Docker!
Today, unikernels took to the stage at DockerCon EU in Barcelona!
As part of the Cool Hacks session in the closing keynote, Anil Madhavapeddy (MirageOS project lead), showed how unikernels can be treated as any other container. He first used Docker to build a unikernel microservice and then followed up by deploying a real web application with database, webserver and PHP code all running as distinct unikernel microservices built using Rump Kernels. Docker managed the unikernels just like Linux containers but without needing to deploy a traditional operating system!
This kind of integration helps put unikernels into the hands of developers everywhere and combines the familiar tooling and real-world workflows of the container ecosystem with the improved security, efficiency and specialisation of unikernels. We’ll finish off this post with details of how you can get involved — but first, before we go into Anil’s demonstration in more detail, some background about why unikernels matter, and why it makes sense to use Docker this way.
Why Unikernels?
As companies have moved to using the cloud, there’s been a growing trend towards single-purpose machine images, but it’s clear that there is significant room for improvement. At present, every VM has to Continue reading
A community site for Unikernels
Word about unikernels is spreading and more people are trying to learn about this new approach to programming the cloud. This community site aims to collate information about the various projects and provide a focal point for early adopters to understand more about the technology and become involved in the projects themselves.
Image Credit: Blake Thomson from Noun Project