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DNSGlobe – Rust TUI to watch DNS propagate around the world

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Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#31

Post by AndyMcConachie »

MaulingMonkey wrote: post #15
teddyh wrote: post #2

The myth of DNS “propagation” needs to die. Changed DNS entries do not “propagate”. The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. DNS resolvers are not linked geographically; there is no “propagation”. If this tool was querying a list of widely-used public (and/or private) DNS resolvers, it might be useful. But pretending that DNS entries propagate geographically does not do anyone…

> The myth of DNS “propagation” needs to die. What's the actual issue? Are you being frustrated by people laboring under the assumption that DNS records are being sent by carrier pidgeon or something? > There is no geographical connection whatsoever. DNS censorship will presumably be based on geopolitical boundaries, which in turn are bound by geography. And I wouldn't be entirely suprised if poor network connections…

>> The myth of DNS “propagation” needs to die.

> What's the actual issue? Are you being frustrated by people laboring under the assumption that DNS records are being sent by carrier pidgeon or something?

The actual issue is that some people misunderstand how DNS works, and the notion that records propagate doesn't help people understand it better. It propagates a misunderstanding of DNS.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#32

Post by phikappa »

AndyMcConachie wrote: post #31
MaulingMonkey wrote: post #15

Earlier quoted context omitted.

> The myth of DNS “propagation” needs to die. What's the actual issue? Are you being frustrated by people laboring under the assumption that DNS records are being sent by carrier pidgeon or something? > There is no geographical connection whatsoever. DNS censorship will presumably be based on geopolitical boundaries, which in turn are bound by geography. And I wouldn't be entirely suprised if poor network connections…

>> The myth of DNS “propagation” needs to die. > What's the actual issue? Are you being frustrated by people laboring under the assumption that DNS records are being sent by carrier pidgeon or something? The actual issue is that some people misunderstand how DNS works, and the notion that records propagate doesn't help people understand it better. It propagates a misunderstanding of DNS.

DNSGlobe – Rust TUI to watch misunderstandings about DNS propagate around the world (github.com/514-labs)

There I fixed it for you.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#34

Post by blacklite »

orangeboats wrote: post #11
OptionOfT wrote: post #8

Vibe-coded. Sorry. https://github.com/514-labs/dnsglobe/blob/c29802162636832e88... You take the `other`, do a `to_string()` on it, which creates a String representation. Then you pass a reference to that String, and, in the case it doesn't contain `time out` or `timeout` or `refused`, the reference gets turned AGAIN into a String (i.e. new allocation), truncated to 48, and then returned. There is no check whether tha…

It's gotten to the point that the moment I see "Rust" and "TUI" together, I immediately assume it's vibe coded. The combination just seems to be vibe coders' favorite, for some reason.

That's not whose favorite it is; it's the favorite of who's doing the work. :)

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#35

Post by drcongo »

LouisvilleGeek wrote: post #20

Not sure of why everyone is negative against this tool? I quite like it. Thanks for sharing!

I like it too. I'll almost certainly get a lot of use out of this and not once will I ever get upset that it uses the word propagation.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#36

Post by jon-wood »

toast0 wrote: post #10
teddyh wrote: post #2

The myth of DNS “propagation” needs to die. Changed DNS entries do not “propagate”. The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. DNS resolvers are not linked geographically; there is no “propagation”. If this tool was querying a list of widely-used public (and/or private) DNS resolvers, it might be useful. But pretending that DNS entries propagate geographically does not do anyone…

a) different DNS systems get the change out to all the authoritatives different ways. Some of them with much delay. Delays are hopefully minimal on modern systems, but I've worked with bad systems where you change dns in the api and it takes minutes and sometimes hours for the authoritatives to start returning new results; traditional notify/axfr based systems often have a queue of several seconds at least. b) as res…

> Delays are hopefully minimal on modern systems

The delays are almost always self inflicted by people who've blindly put 36400 in the TTL field like some sort of magic charm rather than considering how long they want the cache expiry to be. Long ago I was one of them and then I had the company greybeard point out that DNS record updates are a thing we had control over - just drop the TTL to 30 seconds or whatever a day before a planned change of servers and (barring the odd stubborn resolver which thinks it knows better than you do) the time it takes for those caches to refresh goes from 24 hours to 30 seconds.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#37

Post by jon-wood »

tgv wrote: post #28
muppetman wrote: post #24

Earlier quoted context omitted.

Thank you. I have this discussion all the time. The argument I get back "Right, but it seems like the change takes awhile because of the DNS cache expiring, so it's the same as propagating". My counter to that is to say "If I punch you in the mouth, would you just tell people I'd asked you be to be quiet, or would you use the right explanation as to what'd happened?" (It's a stupid counterargument, btw, but it ends t…

But is there a functional difference between push and pull in this case? Is there something that cannot be explained in terms of propagation? Perhaps timing: there's no reason for propagation to wait an hour or a day. BTW, only last week I explained a potential problem of a DNS change with caching, and it was understood. There doesn't seem to be a need to simplify it.

There is absolutely a reason for propagation to wait an hour or a day, and you've set that value in the TTL field for the record in question. It stands for Time To Live and specifies how long downstream resolvers should cache the last value they saw before querying the authoritative server again, if you set that value to a few seconds then almost every DNS resolver in the world will get updated values within a few seconds as they expire the cached value.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#38

Post by teddyh »

browningstreet wrote: post #21
teddyh wrote: post #2

The myth of DNS “propagation” needs to die. Changed DNS entries do not “propagate”. The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. DNS resolvers are not linked geographically; there is no “propagation”. If this tool was querying a list of widely-used public (and/or private) DNS resolvers, it might be useful. But pretending that DNS entries propagate geographically does not do anyone…

Ehh do you remember the defaults back in the day? And how long local vs intermediary vs backbone TTLs could be cached for, even above and beyond the set TTL? The propagation part refers to how long it would take for all those cached requests to expire and when you could tell some random client they should be able to see the new value. Especially when you forgot to lower the TTL ahead of time. It’s a term of art and i…

> local vs intermediary vs backbone TTLs

This is an example of the myth in action. There are no such things. There is a single resolver, which you use, and a set of authoritative server, which that resolver will query when the TTL in the resolver’s cache times out. There is no chain of resolvers.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#39

Post by teddyh »

seamossfet wrote: post #18
OptionOfT wrote: post #8

Vibe-coded. Sorry. https://github.com/514-labs/dnsglobe/blob/c29802162636832e88... You take the `other`, do a `to_string()` on it, which creates a String representation. Then you pass a reference to that String, and, in the case it doesn't contain `time out` or `timeout` or `refused`, the reference gets turned AGAIN into a String (i.e. new allocation), truncated to 48, and then returned. There is no check whether tha…

Nothing wrong with vibecoding a toy project.

There is if you present it to others without telling anyone it’s slop.

Re: DNSGlobe – Rust TUI to watch DNS propagate around the world

#40

Post by teddyh »

MaulingMonkey wrote: post #15
teddyh wrote: post #2

The myth of DNS “propagation” needs to die. Changed DNS entries do not “propagate”. The old cached DNS entries in DNS resolvers simply expire, in an arbitrary order. DNS resolvers are not linked geographically; there is no “propagation”. If this tool was querying a list of widely-used public (and/or private) DNS resolvers, it might be useful. But pretending that DNS entries propagate geographically does not do anyone…

> The myth of DNS “propagation” needs to die. What's the actual issue? Are you being frustrated by people laboring under the assumption that DNS records are being sent by carrier pidgeon or something? > There is no geographical connection whatsoever. DNS censorship will presumably be based on geopolitical boundaries, which in turn are bound by geography. And I wouldn't be entirely suprised if poor network connections…

Yes, I am constantly needing to disabuse people of their misconception that DNS changes start to apply gradually by geographic distance, instead of applying arbitrarily by pure chance of when each resolver happened to query the record previously.
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