IoT Anxiety
Sometimes small things can keep you awake at night.
Ansible for Networking: A Primer
Learn how to use Ansible for network automation in this step-by-step guide.
Follow-up: Nexus-OS Dropping Configuration Commands
Not long after I published the let’s drop some configuration commands rant I got a very nice email from Nicolas Delecroix, Technical Marketing Engineer in Cisco INSBU, effectively saying “Would you have time for a short WebEx call to discuss the root cause of the problem and what we did to fix it?”
Of course I agreed and here’s what they told me:
Read more ...Hacker dumps, magnet links, and you
In an excellent post pointing out Wikileaks deserves none of the credit given them in the #MacronLeaks, the author erroneously stated that after Archive.org took down the files, that Wikileaks provided links to a second archive. This is not true. Instead, Wikileaks simply pointed to what's known as "magnet links" of the first archive. Understanding magnet links is critical to understanding all these links and dumps, so I thought I'd describe them.The tl;dr version is this: anything published via BitTorrent has a matching "magnet link" address, and the contents can still be reached via magnet links when the original publisher goes away.
In this case, the leaker uploaded to "archive.org", a popular Internet archiving resource. This website allows you to either download files directly, which is slow, or via peer-to-peer using BitTorrent, which is fast. As you know, BitTorrent works by all the downloaders exchanging pieces with each other, rather getting them from the server. I give you a piece you don't have, in exchange for a piece I don't have.
BitTorrent, though still requires a "torrent" (a ~30k file that lists all the pieces) and a "tracker" (http://bt1.archive.org:6969/announce) that keeps a list Continue reading
Using a Makefile with Markdown Documents
It’s no secret that I’m a big fan of using Markdown (specifically, MultiMarkdown) for the vast majority of all the text-based content that I create. Over the last few years, I’ve created used various tools and created scripts to help “reduce the friction” involved with outputting Markdown source files into a variety of destination formats (HTML, RTF, or DOCX, for example). Recently, thanks to Cody Bunch, I was pointed toward the use of a Makefile to assist in this area. After a short period of experimentation, I’m finding that I really like this workflow, and I wanted to share some details here with my readers.
First, if you’re not familiar with make and its use of a Makefile, check out this introduction. There’s a ton of power and flexibility here, of which I’ve only scratched the surface so far. The basic gist behind a Makefile is that it provides a set of instructions to the make command. Each set of instructions is tied to a target, which has one or more dependencies. In the “traditional” use cases for make, this is to allow programmers to define how a set of files should be compiled as well Continue reading
Anonymity and Abuse Reports
Last Thursday, ProPublica published an article critiquing our handling of some abuse reports that we receive. Feedback from the article caused us to reevaluate how we handle abuse reports. As a result, we've decided to update our abuse reporting system to allow individuals reporting threats and child sexual abuse material to do so anonymously. We are rolling this change out and expect it to be available by the end of the week.
I appreciate the feedback we received. How we handle abuse reports has evolved over the last six and a half years of Cloudflare's history. I wanted to take this opportunity to walk through some of the rationale that got us to this point and caused us to have a blindspot to the case that was highlighted in the article.
What Is Cloudflare?
Cloudflare is not a hosting provider. We do not store the definitive copy of any of the content that someone may want to file an abuse claim about. If we terminate a customer it doesn’t make the content go away. Instead, we are more akin to a specialized network. One of the functions of the network that we provide is to add security to the content Continue reading
Top Reasons To Attend AnsibleFest London 2017
I remember the first AnsibleFest I attended – it was San Francisco 2014. I had been with Ansible for a week and had flown out to meet some of my new colleagues.
As a user of Ansible for the past year, I'd discovered how cheery and helpful the community was. "Newbies" dropping by the IRC channel on Freenode were always helped out, no matter how simple the question. The community spirit is something many people comment on when first using Ansible.
I remember meeting core engineer Brian Coca for the first time at that AnsibleFest too, also a recent joiner to the company. Brian was asked that morning if he'd give a talk, a request he calmly accepted as if he'd been asked to make a cup of tea. Top tip – never miss a talk given by Brian, you will learn something new!
Later, during the happy hour, I talked with lots of attendees, many just wanting to tell us how much they'd enjoyed the day. It was great to see the open source community feel extending to our full day conferences.
Two and half years later and I still see that community spirit day in, day out. Only now it's Continue reading
OpenVPN TAP adapter MTU in Windows
Recently I was in need of setting up some windows clients to connect to my OpenVPN server. This server running on Linux, uses a specific MTU value (let’s say 1400) to ensure maximum compatibility with different clients over different links.
In addition to the OpenVPN process itself, the kernel must also know about the correct MTU so packet size could be adjusted before reaching the tun/tap interface.
This is very easy to do in Linux. In fact you most likely do not need to do anything at all. OpenVPN will adjusted the MTU of the tun/tap interface while creating it. You can check the interfaces effective MTU by using ip link show or ifconfig command.
The same however can not be said about Windows. In a typical scenario, OpenVPN is not even directly responsible for creating the said interface. Instead, it requires the interface to be already in placed (which is achieved by calling tapinstall.exe during the initial setup) and then it would connect to it.
So even though you have specified your MTU settings in the OpenVPN profile, at least at the time of writing, this does not reflect the MTU of the interface that Windows kernel would Continue reading