Posts from the Past, May 2018

This month—May 2018—marks thirteen years that I’ve been generating content here on this site. It’s been a phenomenal 13 years, and I’ve enjoyed the opportunity to share information with readers around the world. To celebrate, I thought I’d do a quick “Posts from the Past” and highlight some content from previous years. Enjoy!

May 2017

A year ago, I touched on the topic of using a Makefile with Markdown documents to help streamline the process of generating various output formats.

I also explored the use of custom SSH configurations with SSH bastion hosts and uncovered a very basic (but important) error I’d previously overlooked.

May 2016

Two years ago in May I was using Terraform to build an etcd v2 cluster on OpenStack.

May 2015

Three years ago, I was doing a lot of work in my home lab, automating the setup of physical hosts. That led to a post on a fully automated Ubuntu install, which was also related to this post on using an Apt proxy (via apt-cacher-ng).

May 2014

Four years ago, I shared some useful Markdown tools for OS X. Of those tools, I still use pandoc pretty extensively.

May 2013

Five years ago, Continue reading

DNS in the cloud: Why and why not

As enterprises consider outsourcing their IT infrastructure, they should consider moving their public authoritative DNS services to a cloud provider’s managed DNS service, but first they should understand the advantages and disadvantages.To read this article in full, please click here(Insider Story)

DNS in the cloud: Why and why not

As enterprises consider outsourcing their IT infrastructure, they should consider moving their public authoritative DNS services to a cloud provider’s managed DNS service, but first they should understand the advantages and disadvantages.To read this article in full, please click here(Insider Story)

Response: Vendors Pushing Stretched Layer-2

Got this response to my Stretched Layer-2 Revisited blog post. It’s too good not to turn it into a blog post ;)

Recently I feel like it's really vendors pushing layer 2 solutions, rather than us (enterprise customer) demanding it.

I had that feeling for years. Yes, there are environment with legacy challenges (running COBOL applications on OS/370 with emulated TN3270 terminals comes to mind), but in most cases it’s the vendors trying to peddle unique high-priced non-interoperable warez.

Read more ...

Semantics and complexity of GraphQL

Semantics and complexity of GraphQL Hartig & Pérez, WWW’18

(If you don’t have ACM Digital Library access, the paper can be accessed either by following the link above directly from The Morning Paper blog site, or from the WWW 2018 proceedings page).

GraphQL has been gathering good momentum since Facebook open sourced it in 2015, so I was very interested to see this paper from Hartig and Pérez exploring its properties.

One of the main advantages (of GraphQL) is its ability to define precisely the data you want, replacing multiple REST requests with a single call…

One of the most interesting questions here is what if you make a public-facing GraphQL-based API (as e.g. GitHub have done), and then the data that people ask for happens to be very expensive to compute in space and time?

Here’s a simple GraphQL query to GitHub asking for the login names of the owners of the first two repositories where ‘danbri’ is an owner.

From here there are two directions we can go in to expand the set of results returned : we can increase the breadth by asking for more repositories to be considered (i.e., changing first:2 Continue reading

masscan, macOS, and firewall

One of the more useful features of masscan is the "--banners" check, which connects to the TCP port, sends some request, and gets a basic response back. However, since masscan has it's own TCP stack, it'll interfere with the operating system's TCP stack if they are sharing the same IPv4 address. The operating system will reply with a RST packet before the TCP connection can be established.

The way to fix this is to use the built-in packet-filtering firewall to block those packets in the operating-system TCP/IP stack. The masscan program still sees everything before the packet-filter, but the operating system can't see anything after the packet-filter.


Note that we are talking about the "packet-filter" firewall feature here. Remember that macOS, like most operating systems these days, has two separate firewalls: an application firewall and a packet-filter firewall. The application firewall is the one you see in System Settings labeled "Firewall", and it controls things based upon the application's identity rather than by which ports it uses. This is normally "on" by default. The packet-filter is normally "off" by default and is of little use to normal users.

Also note that macOS changed packet-filters around version 10.10. Continue reading

What Drives IPv6 Deployment?

It's been six years since World IPv6 Launch day on the 6th June 2012. In those six years we've managed to place ever increasing pressure on the dwindling pools of available IPv4 addresses, but we have still been unable to complete the transition to an all-IPv6 Internet.

A Hard Rain’s A-Gonna Fall In Public Cloud

Way back in the early days of the commercial Internet, when we all logged into what seemed to be new but what was actually a quite old service used by academic institutions and government agencies that rode on the backbones of the telecommunications network, there were many, many thousands of Internet service providers who provided the interface between our computers and the network capacity that was the onramp of the information superhighway.

Most of these ISPs are gone today, and have been replaced by a few major telco, cable, and wireless network operators who provide us with our Internet service. …

A Hard Rain’s A-Gonna Fall In Public Cloud was written by Timothy Prickett Morgan at The Next Platform.

NSX Workshop: Secure App Infrastructure and Multi-Site Cloud Networking

NSX Workshops

[Summer 2018] Free NSX Training Workshop near you!

Secure Application Infrastructure and Multi-Site Cloud Networking

 

What: Attend a half-day lecture and lab designed to get you started with Micro-segmentation and Multi-Site Cloud Networking (Disaster Recovery).

Why: Not only will you get a business and technical overview of NSX Data Center, you’ll also receive hands-on experience with the products. We’ll make sure you leave knowing how NSX can help secure and extend your network across multiple sites, and into the cloud.

 

Sneak peek (full agenda in registration links):

  • Security: Understand your network traffic flows and intelligently create security groups and policies, leveraging vRNI, Service Composer, and Application Rule Manager to secure your network.
  • Disaster Recovery: Deep dive into multi-site NSX Data Center topologies, learn how to architect your network overlays, and gain visibility across your virtual and physical networks – all so you can build a resilient and flexible network.

RSVP your spot today (click below):

Weekend Reads 051818: Botnets and Throwhammer

The Facebook freak-out provides an outlet for fears regarding the digital environment we inhabit. A few companies control most channels of information. The gadgets that we use for convenience and entertainment also create the mechanisms for near-total surveillance, from tracking devices in our pockets to wiretaps in our homes—hi, Alexa! Someone besides Santa is watching and knows whether you have been naughty or nice. —Nathanael Blake @Public Discourse

Within just 10 days of the disclosure of two critical vulnerabilities in GPON router at least 5 botnet families have been found exploiting the flaws to build an army of million devices. Security researchers from Chinese-based cybersecurity firm Qihoo 360 Netlab have spotted 5 botnet families, including Mettle, Muhstik, Mirai, Hajime, and Satori, making use of the GPON exploit in the wild. —Swati Khandelwal @The Hacker News

Exploitation of Rowhammer attack just got easier. Dubbed ‘Throwhammer,’ the newly discovered technique could allow attackers to launch Rowhammer attack on the targeted systems just by sending specially crafted packets to the vulnerable network cards over the local area network. Known since 2012, Rowhammer is a severe issue with recent generation dynamic random access memory (DRAM) chips in which repeatedly accessing a row of memory Continue reading

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