How to code: lesson 27

I was reading some code on the Internet today and came across this:


The thing to notice is the hang & symbols in front of the variables, instead of just making things line up. It's a stylistic quirk of the author of this code. It's a good lesson on what not to do.

There is only one important style rule and it is this: make your code look like everyone else's. The question isn't whether it's good or bad, only that it's unusual. Yes, this quick is relatively insignificant, but I point it out is that you should not be tempted, even on the smallest of things.

You see this with the evolution of programmers. In the beginning, their code is quirky as hell. Over time, as they they are exposed to more and more source by others, they start to see how these quirks are irritating, and stop doing them in their own code. The style becomes blander and blander -- but at the same time, the greatness of their construction of the code starts to shine.

When you start writing great code, you'll eventually have to break this rule and do something big and strange. For example, I Continue reading

An Update on IPv6

In the coming weeks another Regional Internet Registry will reach into its inventory of available IPv4 addresses to hand out and it will find that there is nothing left. This is by no means a surprise, and the depletion of IPv4 addresses in the Internet could be seen as one of the longest slow motion train wrecks in history. As of mid June 2015 ARIN has 2.2 million addresses left in its available pool, and at the current allocation rate it will take around 30 days to run though this remaining pool. What does this mean for IPv6?

Open Source Routing: Practical Lab

Earlier, I wrote about some interesting open source routing software that I’ve been exploring lately. In this post, I’ll provide you with some tools to get this lab running on your lab, using Vagrant and Ansible. In this post, I’ll be using VirtualBox, and also Ansible and Vagrant. For this purpose, I’m assuming you’re at least somewhat familiar with these tools. Please checkout my GitHub repository for access to the latest versions of all of the files we’ll discuss below - and an easy way to spin all of this up yourself.

Open Source Routing: Practical Lab

Earlier, I wrote about some interesting open source routing software that I’ve been exploring lately. In this post, I’ll provide you with some tools to get this lab running on your lab, using Vagrant and Ansible. In this post, I’ll be using VirtualBox, and also Ansible and Vagrant. For this purpose, I’m assuming you’re at least somewhat familiar with these tools. Please checkout my GitHub repository for access to the latest versions of all of the files we’ll discuss below - and an easy way to spin all of this up yourself.

Open Source Routing: Practical Lab

Earlier, I wrote about some interesting open source routing software that I’ve been exploring lately. In this post, I’ll provide you with some tools to get this lab running on your lab, using Vagrant and Ansible.

In this post, I’ll be using VirtualBox, and also Ansible and Vagrant. For this purpose, I’m assuming you’re at least somewhat familiar with these tools.

Please checkout my GitHub repository for access to the latest versions of all of the files we’ll discuss below - and an easy way to spin all of this up yourself.

Topology

First, here’s the topology we’ll be working with.

All “circuits” are implemented using VirtualBox host networks, described in the Vagrantfile:

# -*- mode: ruby -*-
# vi: set ft=ruby :

VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
  config.vm.box = "trusty64"
  config.vm.box_url = "http://cloud-images.ubuntu.com/vagrant/trusty/current/trusty-server-cloudimg-amd64-vagrant-disk1.box"
 
  config.vm.define "r1" do |r1|
    r1.vm.host_name = "r1"
    r1.vm.network "private_network",
                         ip: "192.168.12.11",
                         virtualbox__intnet: "01-to-02"
    r1.vm.network "private_network",
                         ip: "192.168.31.11",
                         virtualbox__intnet: "03-to-01"
    r1.vm.network "private_network",
                         ip: "1.1.1.10",
                         virtualbox__intnet: "Network to Advertise"
    r1.vm.provision "ansible" do |ansible|
      ansible.playbook = "r1.yml"
     Continue reading

Open Source Routing: Practical Lab

Earlier, I wrote about some interesting open source routing software that I’ve been exploring lately. In this post, I’ll provide you with some tools to get this lab running on your lab, using Vagrant and Ansible.

In this post, I’ll be using VirtualBox, and also Ansible and Vagrant. For this purpose, I’m assuming you’re at least somewhat familiar with these tools.

Please checkout my GitHub repository for access to the latest versions of all of the files we’ll discuss below - and an easy way to spin all of this up yourself.

Topology

First, here’s the topology we’ll be working with.

All “circuits” are implemented using VirtualBox host networks, described in the Vagrantfile:

# -*- mode: ruby -*-
# vi: set ft=ruby :

VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
 
  config.vm.box = "trusty64"
  config.vm.box_url = "http://cloud-images.ubuntu.com/vagrant/trusty/current/trusty-server-cloudimg-amd64-vagrant-disk1.box"
 
  config.vm.define "r1" do |r1|
    r1.vm.host_name = "r1"
    r1.vm.network "private_network",
                         ip: "192.168.12.11",
                         virtualbox__intnet: "01-to-02"
    r1.vm.network "private_network",
                         ip: "192.168.31.11",
                         virtualbox__intnet: "03-to-01"
    r1.vm.network "private_network",
                         ip: "1.1.1.10",
                         virtualbox__intnet: "Network to Advertise"
    r1.vm.provision "ansible" do |ansible|
      ansible.playbook = "r1.yml"
     Continue reading

How we really know the Sunday Times story is bogus

Stories sourced entirely from "anonymous senior government officials" are propaganda, not journalism. The identities of the sources are hidden not to protect them from speaking out against the government, since they are in fact delivering exactly the message the government wants to get out. Instead, their identities are kept secret so that their message cannot be challenged.

It's not just me claiming this. Every journalistic organization criticizes the practice. Every set of journalistic ethics guidelines calls this unethical.

Yet, somehow it keeps happening. The latest example is the The Sunday Times, Britains largest newspaper, reporting government officials critical of Snowden. We know the story is bogus, because it quotes solely government official spouting the party line. Moreover, even if that weren't the case, it's obvious propaganda, arguing one side of the story, and not even attempting to get the other point of view from Russia, China, or Snowden himself. Snowden is often quoted in newspapers, he can't be that hard to get a hold of. Not contacting Snowden for his side is also a violation of journalistic ethics.

I point this out because there are lots of good criticisms of the story, for example, pointing out that the correct term Continue reading

iPhone 7 rumor rollup: Apple gets funny, iOS 9 drops hints

Humor alert! Humor alert! Yes, as it relates to Apple.And I’m not talking about the standard eye-rolling stuff of corporate dog-and-pony shows such as last week’s Apple Worldwide Developers’ Conference (WWDC) in San Francisco. Nope, here we have Apple enlisting the aid of former SNL comic Bill Hader, who shares a humorous behind-the-scenes peek at what could have been at WWDC… Alas, there were no iPhone 6S or iPhone 7 rumors in there, just a goat and some larger-than-life fingers. But the actual WWDC’s introduction of iOS 9 did spark speculation about the next flagship iPhones.To read this article in full or to leave a comment, please click here

My first Cisco Live!

Even though im still in San Diego, Cisco Live! US 2015 is but a memory.

But what a memory it is! It being my first time attending a Cisco Live conference, I didn’t really know what to expect.

What I was met with, was a conference full of really sharp and nice people. The conference staff was very helpful and polite and really made an impression on me, from the time I first stepped onto the pavement outside San Diego convention center.

We (I brought my better half to the US) arrived very late on saturday, so after a good nights sleep I took the bus to the convention center to register and pick up the first piece of swag, the famous Cisco Live bag.

One of the great benefits of attending the conference was meeting with my good friend Daniel Dib (from lostintransit.se). I hadn’t seen him since January, so it was really cool to meet up with him during the week.

On Monday Daniel and I attended a session together, but most other sessions I went to alone. For the record, I paid for this trip out of my own pocket, so I didn’t have any co-workers Continue reading

Cisco Live 2015 – Helping Others

Another year, another Cisco Live.  Boy, was it a good one.  San Diego is a great city, and convention center there is plenty big to take care of all 25k attendees.  On top of that, the city itself is equipped to handle groups of 40 roaming the streets looking for food and entertainment.

This year’s event had the usual stuff that everyone talks about – breakout session, keynotes, exams, etc. – but Cisco stepped outside of technology this year by helping others.

  • Stop Hunger Now Volunteer Space – Cisco partnered with Stop Hunger Now and set up a space where attendees could assemble meal kits to fight hunger worldwide.  I believe the final number was 100,656 kits assembled, which is a fantastic number.  I’m ashamed to say, though, that I missed this due to scheduling issues, but I’m proud of Cisco and the attendees for participating.
  • Mike Rowe Works Foundation – The keynote speaker this year was Mike Rowe, whom most of us know from his TV show Dirty Jobs.  His foundation helps to support skilled labor movements in order to keep all jobs meaningful.  As part of his appearance, Cisco gave his foundation a nice check for $20,000 and promised another Continue reading

CORE Network Emulator updated to 4.8

The CORE Network Emulator has been updated to version 4.8. This new version fixes the issues I noted in my previous review of CORE release 4.7. It also implements some new features. See the CORE 4.8 release notes for all the details.

The most visible change is the addition of some new services — most notably a new Docker service that will allow Docker containers to be used as nodes in the simulation scenario.

More about CORE

I’ve written a lot about the CORE Network Emulator and all my previous posts are still relevant to CORE 4.8 — except where I discuss the bugs in previous versions that are fixed in the latest release. If you have not used the CORE Network Emulator before, I suggest you read the following posts, in order:

This should get you started using the CORE Network Emulator. If you wish to learn more, please read my other posts about CORE and consult the CORE documentation.

Install CORE 4.8 from packages

One can Continue reading

Openstack and Docker – Part 2

This is a continuation of my previous blog on Openstack and Docker. In this blog, I will cover Openstack Docker heat plugin and Magnum. Following are some of the items that Nova Docker driver cannot do currently: Passing environment variables Linking containers Specifying volumes Orchestrating and scheduling the containers Heat docker plugin solves problems 1-3 … Continue reading Openstack and Docker – Part 2 →

Openstack and Docker – Part 1

In this blog, I will cover the different ways in which Openstack can create and manage Docker Containers. The 3 predominant approaches are using Nova Docker driver, Heat Docker plugin and Magnum. Magnum is pretty new and is under development. Openstack is opensource cloud orchestration software and Docker is opensource container management software. For this … Continue reading Openstack and Docker – Part 1 →

Building a Simple Network TDD Framework

In the following series of posts I will show how to build a simple Test-Driven Development framework for Cisco devices. This framework will allow a network engineer to define traffic patterns in a human-readable format and automatically check if those assumption hold. It will be built as a series of Ansible modules and playbooks. The idea is to show an example of how programming can be used by network engineers even now, before all devices acquire their own APIs as well as introduce some well-known programming paradigms and best practices to network engineers thereby making a small step towards networking nirvana a.k.a. SDN. The reader is assumed to have only a basic networking, linux and python programming skills.

Continue reading

Russia, China reportedly crack Snowden’s files, identify US, UK spies

Russian and Chinese intelligence agencies have reportedly decrypted files of former U.S. National Security Agency contractor and leaker Edward Snowden, and have identified British and U.S. secret agents.MI6, the U.K.’s secret intelligence service, has withdrawn agents from overseas operations in hostile countries, according to a report in the Sunday Times of London, citing U.K. government officials and Western intelligence agencies.The report contains some apparently contradictory information. Although The Sunday Times quoted a U.K. Home Office official saying that Snowden has “blood on his hands,” it also quoted a government source saying that there was no sign that agents have been hurt.To read this article in full or to leave a comment, please click here

With payroll in arrears, online antivirus seller shuts doors

The sudden shutdown of a computer tech support call center has left some of its employees wondering if they will be paid.EZ Tech Support, based in Portland, Oregon, took calls from people who had advertising software installed on their computers that warned of possible security and performance problems. The programs implored people to call the company’s number, which was displayed amid warnings.The company stopped taking calls earlier this week, according to two former EZ Tech Support employees. Contacted by email, its general manager, Gavynn Wells, said he was no longer worked there and was “unclear as to the direction the company will be going into.”To read this article in full or to leave a comment, please click here

SDN for the Network Engineers, What should you do ?

Software Defined Networking is real,everyone talks about SDN, network engineers worry about their jobs and ask below questions. Hundreds if not thousands of articles, a lot of books have been written on SDN. SDN is not a new idea or concept and we see this ping pong game many times but this time it is marketed very… Read More »

The post SDN for the Network Engineers, What should you do ? appeared first on Network Design and Architecture.

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