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Multicast Routing in AWS

Consider for a moment that you have an application running on a server that needs to push some data out to multiple consumers and that every consumer needs the same copy of the data at the same time. The canonical example is live video. Live audio and stock market data are also common examples. At the re:Invent conference in 2019, AWS announced support for multicast routing in AWS Virtual Private Cloud (VPC). This blog post will provide a walkthrough of configuring and verifying multicast routing in a VPC.

AWS ABCs: Granting A Third-Party Access to Your Account

There can be times when you're working on the AWS Cloud where you need to grant limited access to your account to a third-party. For example:

  • A contractor or a specialist needs to perform some work on your behalf
  • You're having AWS Professional Services or a partner from the Amazon Partner Network do some work in your account
  • You're conducting a pilot with AWS and you want your friendly neighborhood Solutions Architect to review something

In each of these cases you likely want to grant the permissions the third-party needs but no more. In other words, no granting of AdministratorAccess policies because it's easy and just works. Instead, adherence to the principle of least privilege.

This post will describe two methods—IAM users and IAM roles—for proving limited access to third-parties.

3 Tools for Getting VMs From Your Datacenter to the AWS Cloud

Here's a simple scenario: you have some Virtual Machines (VMs) in your on-premises environment, likely in VMware vSphere or Microsoft Hyper-V. You want to either fully migrate some or all of those VMs to the AWS Cloud or you want to copy a gold image to the AWS Cloud so you can launch compute instances from that image. Simple enough.

Now, how do you do it?

Can you just export an OVA of the VM, copy it up, and then boot it? Can you somehow import the VMDK files that hold the VM's virtual drive contents? Regardless the eventual method, how do you do it at scale for dozens or hundreds of VMs? And lastly, how do you orchestrate the process so that VMs belonging to an application stack are brought over together, as a unit?

9 Things to Consider When Estimating Time

Often in my career I have to make an estimate about the so-called “level of effort” (LoE) to do a thing.

  • What's the LoE for me to do a demo for this customer?
  • What's the LoE for me to help respond to this RFP?
  • What's the LoE for me to participate in this conference?

The critical metric by which I usually have to measure the LoE is time. People, equipment, venue, materials, and location are rarely ever a limiting factor. Time is always the limiting factor because no matter the circumstance, you can't just go and get more of it. The other factors are often elastic and can be obtained.

And oh how I suck at estimating time.

As soon as the question comes up, “What's the LoE for…", I immediately start to think, ok, if I am doing the work, I can do this piece and that piece, I can read up on this thing and get it done with slightly more time invested, and then yada, yada, yada… it's done!

What I don't account for is the human element. The unexpected. The fact that we're all different and team members will go about their work in their Continue reading

Five Functional Facts About AWS Service Control Policies

Following on the heels of my previous post, Five Functional Facts about AWS Identity and Access Management, I wanted to dive into a separate, yet related way of enforcing access policies in AWS: Service Control Policies (SCPs).

SCPs and IAM policies look very similar—both being JSON documents with the same sort of syntax—and it would be easy to mistake one for the other. However, they are used in different contexts and for different purposes. In this post, I'll explain the context where SCPs are used and why they are used (and even why you'd use SCPs and IAM policies together).

Read on, dear reader!

Five Functional Facts about AWS Identity and Access Management

This post is part of an open-ended series I'm writing where I take a specific protocol, app, or whatever-I-feel-like and focus on five functional aspects of that thing in order to expose some of how that thing really works.

The topic in this post is the AWS Identity and Access Management (IAM) service. The IAM service holds a unique position within AWS: it doesn't get the attention that the machine learning or AI services get, and doesn't come to mind when buzzwords like “serverless” or “containers” are brought up, yet it's used by-or should be used by-every single AWS customer (and if you're not using it, you're not following best practice, tsk, tsk) so it's worthwhile to take the time to really get to know this service.

Let's begin!

AWS ABCs — Network Building Blocks

Given that my technical background is largely in the networking space (exhibit A, exhibit B, exhibit C (CIE)), one of the first things I tried to wrap my head around when being introduced to AWS is how networking works in the AWS cloud.

What I attempted to do was build a mental model by relating cloud networking constructs such as Virtual Private Cloud (VPC), subnets, and routing tables to on-prem, physical networking constructs. This worked pretty well but I did get tripped up at times because some of these constructs don't map exactly one-for-one.

This post will explain the mental model I used while also calling attention to the elements or behaviors that don't map exactly between on-prem and AWS.

AWS ABCs — Can I Firewall My Compute Instances?

In a previous post, I reviewed what a public subnet and Internet Gateway (IGW) are and that they allowed outbound and _in_bound connectivity to instances (ie, virtual machines) running in the AWS cloud.

If you're the least bit security conscious, your reaction might be, “No way! I can't have my instances sitting right on the Internet without any protection”.

Fear not, reader. This post will explain the mechanisms that the Amazon Virtual Private Cloud (VPC) affords you to protect your instances.

AWS ABCs — EC2 Internet Connectivity

So, you've created a compute instance (ie, a virtual machine) on Amazon EC2. Next question: does the instance require access to and/or from the Internet?

Protip: just because you created the instance in the public cloud, i.e. the cloud that you get to over the Internet, it doesn't mean that your instances all need to sit on the Internet. They can have direct inbound and outbound Internet access, no Internet access, or something in between (which I'll explain).

The basic building block for networking on AWS is the VPC (Virtual Private Cloud). Within a VPC, you define your IP space, gateways, ACLs, DHCP options, and more. Gateways will be the focus of this article.

AWS ABCs — Logging Into a New EC2 Instance

Ok, you've just launched an Amazon EC2 instance (ie, a virtual machine) and you're ready to login and get to work. Just once teeeensy problem though… you have no idea how to actually connect to the instance!

This post will walk through how to log into brand new Linux/BSD and Windows instances (the steps are slightly different for different OS families).

Starting a new series: AWS ABCs

I'd be lying if I said that since starting my new job at Amazon Web Services (AWS), I wasn't looking forward to writing about all the new things I was going to learn. Obviously there's the technology and services that make up the platform itself. But there's also the architectural best practices, the design patterns, and answers to questions like “how does moving to the cloud improve my performance/security/reliability?” Admittedly, I have a lot to learn.

On Why I’m Shifting my Career Focus to Software

For the past few months I've been involved in a case study project with some colleagues at Cisco where we've been researching what the most relevant software skills are that Cisco's pre-sales engineers could benefit from. We're all freaking experts at Outlook of course (that's a joke ?) but we were interested in the areas of programming, automation, orchestration, databases, analytics, and so on. The end goal of the project was to identify what those relevant skills are, have a plan to identify the current skillset in the field, do that gap analysis and then put forward recommendations on how to close the gap.

This probably sounds really boring and dry, and I don't blame you for thinking that, but I actually chose this case study topic from a list of 8 or so. My motivation was largely selfish: I wanted to see first-hand the outcome of this project because I wanted to know how best to align my own training, study, and career in the software arena. I already believed that to stay relevant as my career moves along that software skills would be essential. It was just a question of what type of skills and in which specific Continue reading

The Anatomy of a Cisco Spark Bot

I spent a long time creating my first Spark bot, Zpark. The first commit was in August and the first release was posted in January. So, six months elapsed time. It's also over-engineered. I mean, all it does is post messages back and forth between a back-end system and some Spark spaces and I ended up with something so complex that I had to draw a damn block diagram in the user guide to give people a fighting chance at comprehending how it works.

Its internals could've been much simpler. But that was part of the point of creating the bot: examining the proper architecture for a scalable application, learning about new technologies for building my own API, learning about message brokers, pulling my hair out over git's eccentricities and ultimately, having enough material to write this blog post.

In this post I'm going to break down the different functional components of Zpark, discuss what each does, and why-or not-that component is necessary. If I can achieve one goal, it will be to retire to a tropical island ASAP. If I can achieve a second goal, it will be to give aspiring bot creaters (like yourself, presumably) a strong Continue reading

Explain Cisco ETA to Me in a Way That Even My Neighbor Can Understand It

Cisco Encrypted Traffic Analytics (ETA) sounds just a little bit like magic the first time you hear about it. Cisco is basically proposing that when you turn on ETA, your network can (magically!) detect malicious traffic (ie, malware, trojans, ransomware, etc) inside encrypted flows. Further, Cisco proposes that ETA can differentiate legitimate encrypted traffic from malicious encrypted traffic.

Uhmm, how?

The immediate mental model that springs to mind is that of a web proxy that intercepts HTTP traffic. In order to intercept TLS-encrypted HTTPS traffic, there's a complicated dance that has to happen around building a Certificate Authority, distributing the CA's public certificate to every device that will connect through the proxy and then actually configuring the endpoints and/or network to push the HTTPS traffic to the proxy. This is often referred to as “man-in-the-middle” (MiTM) because the proxy actually breaks into the encrypted session between the client and the server. In the end, the proxy has access to the clear-text communication.

Is ETA using a similar method and breaking into the encrypted session?

In this article, I'm going to use an analogy to describe how ETA does what it does. Afterwards, you should feel more comfortable about how Continue reading

Say Hello to Zpark, my Cisco Spark Bot

For a long while now I've been brainstorming how I could leverage the API that's present in the Cisco Spark collaboration platform to create a bot. There are lots of goofy and fun examples of bots (ie, Gifbot) that I might be able to draw inspiration from, but I wanted to create something that would provide high value to myself and anyone else that choose to download and use it. The idea finally hit me after I started using Zabbix for system monitoring. Since Zabbix also has a feature-rich API, all the pieces were in place to create a bot that would act as a bit of middle-ware between Zabbix and Spark. I call the bot: Zpark.

2017 End of Year Blog Statistics

Didn't I just write the 2016 statistics post like… last week? Another year has flown by and with it another year of attempting to prioritize my writing. I'll be honest, I'm not optimistic about what I'm going to find when I compare 2017 to 2016. It was a year filled with a lot of change and opportunity so I'll use that as my excuse as to why I didn't write as much or as often as I had planned.

I was thinking though: every year I set a goal of writing more posts than the previous year, but that's only 1 metric to go by. Most of my posts are very detailed and fleshed out. It's nothing to write a post that's 1000 words. I regularly eclipse 2000 words and have even hit 3000 words. Perhaps I should be thinking more about word count and not post count? Certainly a 2000 word post takes more effort than a 1000 word post. On the other hand, word count says nothing about quality and could easily lead to excessive wordiness and run-on posts just to tilt the metrics.

Enough musing. Let's review the data!

My Personal Look Back on 2017

Continuing in a tradition I started early this year where I take a look back at the year that just passed, I've again been very fortunate to have had an amazing year, both in my professional and personal lives. Writing this post is my way of forcing myself to stop and take notice of what I was involved in (something I'm not very good at letting myself do in the moment) and also give readers a chance to see the “me” behind the scenes.

Let's go through the list!

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