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Why is DNS still hard to learn?

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Re: Why is DNS still hard to learn?

#81

Post by bdavbdav »

alexjplant wrote: post #28
shon wrote: post #2

It’s not. It’s one of the few things that hasn’t changed much and it’s operation is fairly straightforward. dig is a little confusing. It’s more capable but less straightforward than good old nslookup (which still works fine BTW). I think partly DNS and the core protocols may seem confusing to younger people in the industry because so much stuff “just works” now. For example, today wifi routers “just work” right out…

When I was 14 I (poorly) administered an Active Directory environment with mail, web, and CIFS for a restaurant without understanding DNS or DHCP. Instead of setting the WRT54G's DHCP server to hand out the domain controller's static IP as the DNS server for proper name resolution I just used IP addresses and host file entries to make everything work. I also had the MX record for the domain set to the router's WAN IP…

Same boat at a similar age. (Ab)using AD taught me a lot about DNS, largely after the fact. Lots of “so that’s why that didn’t work…” moments later down the line.

Re: Why is DNS still hard to learn?

#82

Post by [deleted] »

knome wrote: post #51
jeroenhd wrote: post #43

Earlier quoted context omitted.

I think it is hard to learn... using the tools people used to learn DNS with. BIND is great at what it does, but its configuration files suck and its manual is long, terse, and unnecessarily complex sometimes. Dig is powerful, but abbreviates everything like we're on an 80 column terminal. At times Wireshark was a better tool debugging DNS issues than Dig was. Give someone PowerDNS or another modern DNS server and I…

>I don't know what the semicolons before the lines are supposed to convey but they're only making things confusing all of the lines that aren't part of the query answer are prefixed with semicolons. so it's basically a comment character. presumably to ease processing of the data it spits out. You know. So you can `dig google.com | grep -v '^;' | grep . | awk '{ print $5 }'` easily. I can imagine people using it in a…

[deleted]

Re: Why is DNS still hard to learn?

#83

Post by dclowd9901 »

jl6 wrote: post #78

It's one of those things where there is a mismatch between how easy it seems to be, and how hard it turns out to be. We all use DNS every day, and it seems really easy. The everyday language of DNS is: domain names, lookups, IP addresses. This language is exposed in browsers for all to see, and through this exposure we develop a mental model of how we think it works. But under the covers there is a whole new language…

It’s the distribution part that makes it hard right? There’s a shit ton of dark magic happening above the atomic level of an individual node that both introduces the majority of the complexity and also the majority of the obfuscation.

DNS is easy. An organization agnostic distribution of information is _really_ tricky.

Re: Why is DNS still hard to learn?

#84

Post by dclowd9901 »

jeroenhd wrote: post #71
knome wrote: post #51

Earlier quoted context omitted.

>I don't know what the semicolons before the lines are supposed to convey but they're only making things confusing all of the lines that aren't part of the query answer are prefixed with semicolons. so it's basically a comment character. presumably to ease processing of the data it spits out. You know. So you can `dig google.com | grep -v '^;' | grep . | awk '{ print $5 }'` easily. I can imagine people using it in a…

Now I just wonder what the double semicolons mean and why they're different from single semicolons :) It's fine, I can Google the answer, I just wished I didn't need to. I already know to use +short when I just want the result(s). I use it in a script to detect and resolve my Pihole's random freezes (by timing the lookup and rebooting the VM every time a lookup fails or takes longer than 200ms, janky but it works).

Perhaps there is info that would normally be present and isn’t, hence stacked semicolons.

Re: Why is DNS still hard to learn?

#86

Post by msie »

bratgpttamer wrote: post #14

I feel like DNS is one of the more straightforward protocols, especially on a practical level, and especially given that most interfaces are a dropdown and two text boxes. I have noticed a lot of developers shy away from it, probably because they don't use it much or it's not their job (rather than it being hard).

Exactly. Why waste time learning something I will only use once or twice a year or 10 times in my career? Or that someone else (who is an expert) can fix for me?

Re: Why is DNS still hard to learn?

#87

Post by monksy »

Spivak wrote: post #44
NikolaNovak wrote: post #31

Earlier quoted context omitted.

I may agree with your point but don't understand the social justice aspect at all; makes it feel like it's something just added in. I think both our perspective as a society and thereforo educational goals have changed over decades, laterally to any social justice aspect. If nothing else, there are order of magnitude more developers of all sorts today than 25 years ago, both as absolute numbers and as relative percen…

And when there is social justice or involved it's about getting more people involved in engineering. I can see where "hey, quit being gross to women" can be read as excluding the unsavory but that framing presumes that a world where that's an intrinsic immutable property of a person. I really don't buy the "some people just can't help being an asshole so having a rule against assholes is exclusionary." The most contr…

This is kind of where I was going with that, but I don't agree with the way its being described. I 100% agree with cracking down on individuals who are hostile based on identity, that was unreasonable and should continue to be excluded from projects.

The history of the developer circles is that we've been a bit rough with the language. (mount, finger, touch, zip, etc are perfectly acceptable things for linux commmands.. theres even a joke about it). Unsavory jokes in mailing list/code bases, etc. However, we've come upon a bunch of people who take the aggressively negative view on the words and interactions used and have taken it upon themselves to rename things and force changes. (Master/main, master/slave, whitelist/blacklist, [theres a whole list of these "undesirable" language things] etc ).

On top of that the CoC has implemented toxic positivity rules on projects. Implementers overlook the fact that they have been used as a weapon to be put in the project it's self. (There have been examples of racial, and gender based discrimination in the enforcement of the rules)

All of this brings in people who do not contribute in a UX, DX, engineering, management sort of way. Even when these things are abused/enforced poorly it still has a significant silencing effect and distancing effect from those who would be a positive contributor but is reluctant to participate.

Re: Why is DNS still hard to learn?

#88

Post by f1shy »

tristor wrote: post #30

I don't agree with this article. I think DNS is something few people take the time to learn, but it's not actually hard to learn. One of the great things about DNS is that the system itself will tell you about it's internal state in response to queries. It's very easy to inspect a DNS server for a known zone and understand how it works, and there's very good tooling that's free and widely available to do this (like d…

Absolutely agree. Back in the days, I was very inexperienced, I was thrown to the task of administering DNS (with BIND) and Sendmail. I had 100+ servers. The first couple of month was a lot of reading, and understanding things, but relatively fast I got a good understanding of it. After 6 month I was teaching DNS to other teams in other countries for the same company. It was not at all hard. I'm a very average engineer, and from 0 to explaining to others in 6 month, is by no means a difficult topic.

Re: Why is DNS still hard to learn?

#89

Post by zehemer »

jeroenhd wrote: post #43
tristor wrote: post #30

I don't agree with this article. I think DNS is something few people take the time to learn, but it's not actually hard to learn. One of the great things about DNS is that the system itself will tell you about it's internal state in response to queries. It's very easy to inspect a DNS server for a known zone and understand how it works, and there's very good tooling that's free and widely available to do this (like d…

I think it is hard to learn... using the tools people used to learn DNS with. BIND is great at what it does, but its configuration files suck and its manual is long, terse, and unnecessarily complex sometimes. Dig is powerful, but abbreviates everything like we're on an 80 column terminal. At times Wireshark was a better tool debugging DNS issues than Dig was. Give someone PowerDNS or another modern DNS server and I…

> As a user of the "--color" flag for the `ip` command, I'd love to see tools like dig produce more modern output

https://github.com/ogham/dog is pretty good in that regard

Re: Why is DNS still hard to learn?

#90

Post by dclowd9901 »

Dylan16807 wrote: post #13
pgray wrote: post #5

the joke i've always heard is DNS combines 2 of the hardest problems in CS: naming things and cache invalidation

It comes with a validity counter in seconds, and you can be very very loose about counting those seconds. It's not the hard kind of cache invalidation. You don't really have to do "invalidation" at all. And on the server side, it's perfectly acceptable to send a mix of old and new versions for a while.

> It's not the hard kind of cache invalidation. You don't really have to do "invalidation" at all.

One of the points he brings up is negative cache, or caching the dns into a state that it won’t retrieve a resolved address even if it’s available simply because the negative case is cached.

Invalidation is definitely a part of it, mostly because you kind of can’t.

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