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Category Archives for "Networking"

IS-IS Multi Instance: RFC8202

Multi-Instance IS-IS
One of the nice things about IS-IS is the ability to run IPv6 and IPv4 in the same protocol, over a single instance. So long as the two topologies are congruent, deploying v6 as dual stack is very simply. But what if your topologies are not congruent? The figure below illustrates the difference.

In this network, there are two topologies, and each topology has two different set of level 1/level 2 flooding domain boundaries. If topology 1 is running IPv4, and topology 2 is running IPv4, it is difficult to describe such a pair of topologies with “standard” IS-IS. The actual flooding process assumes the flooding domain boundaries are on the same intermediate systems, or that the two topologies are congruent.

One way to solve this problem today is to use IS-IS multi-topology, which allows the IPv6 and IPv4 routing information to be carried in separate TLVs so two different Link State Databases (LSDBs), so each IS can compute a different Shortest Path Tree (SPT), one for IPv4, and another for IPv6. Some engineers might find the concept of multi-topology confusing, and it seems like it might be overkill for other use cases. For instance, perhaps you do Continue reading

Why leave a vendor job….twice?

Over the past few months I’ve been working hard on my new start-up company PeakFactory, it’s going really well, but for this post I want to focus on the reason why I chose to leave the companies I used to work for. I thought this was relevant, as many people have asked me why, but also in general there is a lot of discussion how to advance your career in different directions.

Why leave a comfortable and good job at all?

Back in 2013 I was working in a very good position, where I had a lot of freedom in choosing the customers I’d like to work on and was involved in all technical aspects of a project (pre-sales, proof of concepts, implementation and support). Still I had this feeling that I wanted to explore more an different areas for a wider audience. Which is why I decided to start working for a networking vendor. My main reason for choosing a vendor is that I could leverage my experience in the technology and apply it for a wider audience (maybe even worldwide)

Why work for Cisco and Juniper?

In early 2014 I got in touch with Cisco and I left Continue reading

NetDevOps: what does it even mean?

Move over “selfie” — “NetDevOps” is the hottest buzzword that everybody is talking about! It’s so popular that the term even has its own hashtag on Twitter. But when you take the word out of social media, does anyone really know what it means? Or how this perfect portmanteau can revolutionize your data center? Let’s take a moment to discuss what NetDevOps really is all about. In this post, we’ll go over the definition, the best practices, and the tech that best incorporates NetDevOps. Now, when you see #NetDevOps appear on your feed, you can tweet it out with confidence.

What does it all mean?

If you understand the basic principles of DevOps, then congratulations! You’re two-thirds of the way to grasping the concept of NetDevOps. For the uninitiated, DevOps embraces the ideology of interoperability and communication between the development and operations teams in order to break down silos and create better products. The movement also encourages automation and monitoring in order to increase efficiency and reduce error.

DevOps is certainly a great movement, but like the VCR and the DVD player, something new came along and improved upon it. This is where NetDevOps comes in. So, what exactly is Continue reading

REVIEW: Turbonomic, VMware virtualization management tools

Virtualization management tools are becoming a must-have for enterprises that are grappling with increasingly dynamic infrastructure environments. Virtualization management tools allow for proactive capacity planning, which increases performance efficiency, keeps costs in check and avoids disruption.To read this article in full or to leave a comment, please click here(Insider Story)

REVIEW: Turbonomic, VMware virtualization management tools

Virtualization management tools are becoming a must-have for enterprises that are grappling with increasingly dynamic infrastructure environments. Virtualization management tools allow for proactive capacity planning, which increases performance efficiency, keeps costs in check and avoids disruption.To read this article in full or to leave a comment, please click here(Insider Story)

Worth Reading: The Largest Hole in Cloud Security

Configuration errors made while using cloud-storage services are common, security experts say, and often occur when users set access permissions so someone outside of the company—say, a vendor—can see data. “More data has been lost due to poor configuration than anything else on the cloud,” says Vincent Liu a partner at Bishop Fox, a computer-security consulting firm. —Robert McMillan @ Market Watch

The post Worth Reading: The Largest Hole in Cloud Security appeared first on rule 11 reader.

KRACK WPA2 Vulnerability Announced – Upgrade Now

If you haven’t already heard about the KRACK (Key Reinstallation Attack) vulnerability announced today, head over to the information page at https://www.krackattacks.com/ as quick as your fingers will take you because Mathy Vanhoef of imec-DistriNet has found a vulnerability in the WPA2 protocol which has a very wide impact.

KRACKKRACK Attack

The challenge here is that for this isn’t a bug in any particular implementation or commonly-used library; rather, it’s a vulnerability in the protocol itself which means that any correct implementation of the protocol is vulnerable. This also does not just apply to wireless access points; remember that most cell phones can also act as wireless APs for purposes of wireless tethering, so they may be vulnerable too.

Impressively, a number of vendors have released code which has been patched for the vulnerability today, and a number of vendors included fixes before today’s public announcement. However, those are useless if people don’t install the upgrades. I strongly advise going now and finding what your wireless vendor has done, and installing any available patched code.

Ubiquiti Update

Since I know you’re all following my Ubiquiti experiences, I’ll note that UBNT released code Continue reading

Network Automation: Leaky Abstractions

I hear people talk about leaky abstractions all the time. I’m not sure that some of the people that use it have researched the term.

As network-automation blurs the line between software and networking, terms like this are used more commonly than you might expect.

When you hear someone say ‘leaky abstraction’, what does it really mean? This question drove me to a little research effort.

The term ‘leaky abstraction‘ was popularised in 2002 by Joel Spolsky. I totally misunderstood this statement when I first heard it, so naturally the researcher in me went off trawling the web to get a more correct view.

My original and misinformed understanding is explained in the example below.

The Example

Taking the example of a car, the abstraction interface or vehicle controls allows a user to manoeuvre the vehicle between a start and end point whilst keeping the passenger as comfortable as possible.

A car has air modification capability, human body heaters and it can even project audio to your ears. Most vehicles have an on switch (engine start or power switch), they have directional and velocity controls that come in the form of a steering wheel, a set of pedals Continue reading

How to build low-cost IoT sensor networks

Sensor Fusion for Public Space Utilization Monitoring in a Smart City (pdf) is simply the best read for IoT product designers, developers and implementers. It steps through designing a system to measure space utilization in a city — the trade-offs made in sensor selection and calibration, power source selection, network design, data cleaning and normalization, and data processing. The methodology can be generalized for designing any IoT network. The paper is nothing less than a perfect case study about how to build an IoT network.RELATED: 8 tips for building a cost-effective IoT sensor network The most interesting aspects of the paper by Billy Pik Lik Lau, Nipun Wijerathne, and Chau Yuen of the Singapore University of Technology and Design and Benny Kai Kiat Ng of Curtin University is how they matched the sensors to acquire the data at the right resolution to estimate space utilization and built a test bed, minimizing a wide range of implementation issues. To measure space utilization, meaning how populated a space is over multiple time intervals, they chose sound and motion sensors and the fusion of the two. The methodology applied in this paper could be adapted to other sensor types.To read this Continue reading

WPA2 KRACK Vulnerability, Getting Information

*** This page is being updated regularly. Please check back periodically. ***

I'm sure everyone who does anything with networking or Wi-Fi has heard about the announced WPA2 KRACK vulnerability. I won't go into depth with my opinion on it. I'd just like to start a collection of useful information in one single place.

First, the security researcher's website on the attack details:
https://www.krackattacks.com/

Second, read these articles and watch these videos by experts:
Mojo Networks / Pentester Academy Videos: http://blog.mojonetworks.com/wpa2-vulnerability
Aruba Blog: http://community.arubanetworks.com/t5/Technology-Blog/WPA2-Key-Reinstallation-Attacks/ba-p/310045
Aruba FAQ: http://www.arubanetworks.com/assets/alert/ARUBA-PSA-2017-007_FAQ_Rev-1.pdf

*IMPORTANT UPDATE*
What's the TL;DR? There are 9 vulnerabilities that are client related and 1 that is AP / Infrastructure related. All are implementation issues, meaning software patching can fix them! Of the 9 CVE's related to clients, ALL can be mitigated with AP / Infrastructure updates as a workaround, but the infrastructure won't be able to determine if failure is from packet loss issues or attack. The long-term fix is definitely client software patching. The 1 CVE related to AP / Infrastructure is related to 802.11r Fast Transition - if you have it enabled you should patch ASAP. If not, no big Continue reading

25% off SanDisk Ultra 32GB microSDHC UHS-I card with Adapter – Deal Alert

SanDisk has discounted some cards today on Amazon. Their Ultra 32GB microSDHC UHS-I card with Adapter is currently listed for $11.19, which is $0.61 cheaper than the 16GB model. Today they've also priced the 64GB model at $17.99, 128GB for $36.99, and 200GB for $62.99. See these discounts on Amazon, today only.To read this article in full or to leave a comment, please click here

Using the Linux find command with caution

A friend recently reminded me of a useful option that can add a little caution to the commands that I run with the Linux find command. It’s called -ok and it works like the -exec option except for one important difference — it makes the find command ask for permission before taking the specified action.Here’s an example. If you were looking for files that you intended to remove from the system using find, you might run a command like this:$ find . -name runme -exec rm {} \; Anywhere within the current directory and its subdirectories, any files named “runme” would be summarily removed — provided, of course, you have permission to remove them. Use the -ok command instead, and you’ll see something like this. The find command will ask for approval before removing the files. Answering y for “yes” would allow the find command to go ahead and remove the files one by one.To read this article in full or to leave a comment, please click here

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