Tek's Domain

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QMQP: That Other Mail Transfer Protocol

2021-06-29 4 min read Email Networking Sysadmin stuff Tech explained Teknikal_Domain Unable to load comment count

Everyone (okay, everyone this is relevant to) knows what SMTP is, the standard for mail transfer. It’s even in the name, Simple Mail Transfer Protocol, which is how mail servers have been sending mail to other mail servers since… a while. Well, fun fact, there’s another protocol that accomplishes the same goal: QMQP, the Quick Mail Queuing Protocol.

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How DNSBLs Work

2021-06-27 4 min read Email Security Sysadmin stuff Tech explained Teknikal_Domain Unable to load comment count

Ff you’ve dealt with email for any longer than 5 minutes (as an administrator), you already know it’s a mess. There’s so many security measures, so many checks, so many things to combat bad actors and spam. What if we had some way to have some service publish a list of bad DPs, and mail servers could quickly check that mid-transaction so they can have up-to-date information as to if the in-flight message should actually be accepted or not?

Well, we have exactly that. Enter: the DNS Blacklist.

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Graylog, and the Syslog Protocol, Explained

2021-02-19 9 min read Software Sysadmin stuff Tech Tech explained Teknikal_Domain Unable to load comment count

So if you’ve tried enterprise log management systems, you’ve likely heard of Syslog. If you haven’t, Syslog, is, well, a protocol designed to allow multiple hosts to send their system logs over the network to some other server where they can be analyzed and stored. It’s another one of those weird UDP protocols, and this one is actually stupid simple, even in both of the commonly used forms! Oh, we’ll also cover the one piece of software that I use that handles Syslog — Graylog, which by itself is also really cool.

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AbuseIPDB Checking With Postfix

2021-01-28 11 min read Programming Security Software Sysadmin stuff Tech Teknikal_Domain Unable to load comment count

So if you’ve not heard, there’s this website called AbuseIPDB, which, no affiliation, is a website where webmasters can submit reports of abusive IP addresses, and then query those reports, either manually, or using their REST API. And this is how I did exactly that, to help cut down some of the spam on my email server. Let’s get started.

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Moving From Sophos UTM 9 to pfSense

2020-09-01 9 min read Behind the scenes Networking Sysadmin stuff Tech Teknikal_Domain Unable to load comment count
Updated May 4th, 2021

Yeah I figure why not, at the same time that I’m replacing another key piece of network infrastructure, I might as well just replace the (second) most important piece, right? So cue the music, because…

Now, this is a story, all about how my life network got flipped, turned upside down, and I’d like to take a minute, just sit right there, I’ll tell you how I became the prince of a town called Bel Air the owner of a… just… just cut the music. Let’s begin.

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Ah Yes, the SIMPLE Network Management Protocol

2020-07-31 10 min read Networking Rants Sysadmin stuff Tech Tech explained Teknikal_Domain Unable to load comment count

If that title isn’t a dead giveaway, I’m not happy. But yet I will somehow manage to vent my frustrations and explain something at the same time. Today: SNMP, or, “How to gather lots of stats on remote machines,” or, “Because you thought CVS was hard to wrap your head around.”

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Teknikaldomain.me Website Architecture Overview

2020-06-22 17 min read Behind the scenes Tech Web stuff Sysadmin stuff Teknikal_Domain Unable to load comment count

So I just checked in with initialcommit.com, the website run by Jacob Stopak, the same person I collaborated with to help explain the internals of version control systems, not once, but twice even. And he published an overview of how he made the site, and what tools he used. As I was looking, I noticed, we took a very different approach to get to two similar endpoints.

If you just want to see what I did, read on. If you want to see the differences, or are just curious about the various ways that sites can be built, read his first, then come back with that knowledge in mind.

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Complying With the Latest Security Policies

2020-04-12 12 min read Behind the scenes Blog improvements Tech Sysadmin stuff Web stuff Teknikal_Domain Unable to load comment count

Modern websites and modern browsers support a wide range of security features to communicate specifically what is and is not allowed to be loaded, executed, or sent over the network. Being the person that I am, I’m going to comply with the latest guidelines and best practices as much as I can… and it’s a headache.

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Minor Rant: Linux, Scripts, and SetUID

2019-09-14 3 min read Programmer stuff Programming Rants Sysadmin stuff Tech Teknikal_Domain Unable to load comment count

You know the feeling when a system that you’ve used for years, and trusted, suddenly throws a curveball at you with a fun “Yeah you know this simple and concrete rule that’s never broken? Well in this one exception, it is, and nobody ever points it out. Have fun!”

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