It’s important to know your limits. In this case study we find a situation stemming from SMTP being throttled. This is part of the packet capture I received: The top lines show the previous conversation ending. SMTP successfully sent 3 messages. After the 3rd message the mail server stopped responding and retransmits began. This pattern was repeatable. More than that it was repeatable from other EC2 instances. The only thing between the EC2 instances and the mail server was a router and a firewall.

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Alexa App for Kids

If you refer to this post, you’ll see that one of my objectives for this year was to develop an Alexa app for my kids. Well, I am happy to report this objective as completed. The cover art and the image below show the high level architecture. The app idea actually started based on something I was doing for my kids that they really took a liking to. Unfortunately, for this post it might be an idea that I could actually publish and potentially monetize.

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Being that I recently took the plunge to a static site hosted on AWS S3 I thought I would create a post outlining the high-level process for future reference. There are quite a few blogs in the interwebs outining this process, but if this helps someone else too then it’s a win-win. If you are curious as to WHY I migrated, you can find a short bit about that in this post.

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Relentless

This is old news, but I recently found out that Jeff Bezos considered “Relentless” as a possible name for his company instead of Amazon. If this is news to you as well, you can read a short article about it from Business Insider here. Webster Dictionary defines “relentless” this way: showing or promising no abatement of severity, intensity, strength, or pace For some reason this word has stuck with me the past couple of weeks.

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Moving to S3

Moving to S3 I’m currently in the process of moving my blog to Amazon S3. I’m not the first to do this and I won’t be the last. My reasons for this are similar to everyone else. Wordpress is an excellent blogging and site platform. I have really enjoyed working with it and getting to know its innards. As I continuously evaluate the purpose of my site though, I have to keep the technology behind it in sync.

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Well, Tom and the team at CloudShark have put together an excellent packet capture challenge on their blog once again. It has actually been awhile since I’ve dug into a capture due to my recent shift in focus to Amazon Web Services, so this was a lot of fun for me. I feel like once you’re a “packet junkie” you are always one! <span style="color: #ff0000;">*SPOILER ALERT*</span> The rest of this post describes the challenge and the process I followed for solving the challenge.

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I no longer have a need for the Cisco Meraki MX64. It was only used for testing. It is in working condition. It has been reset to defaults and is unclaimed. It comes in the original box with the power and network cable. See the listing here.  

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We spend a lot of time monitoring our internal networks. Obviously, this is where we have the most tools at our disposal and where our actual responsibility lies. But, to provide good service to our customers and/or end users we also need to be aware of what is happening at our Internet providers and above. If you have global services then I recommend you monitor the submarine cables as well. For example, this was the latest submarine cable damage that impacted regions in Africa.

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Author's picture

Chris Sereno

For 11 years networking was my profession with a specialized focus on proactive and reactive performance analysis. More recently I have embraced the AWS platform. This blog reflects my experience both past and present.

AWS Architect at Caterpillar, Inc.

US