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by keeperofdakeys 872 days ago
The ".local" domain specifically is a bad choice as many platforms use MDNS instead of DNS for looking up those names. Leading to issues resolving names on some client devices. It's also very common due to Microsoft suggesting it as best practise in the early days of AD.
2 comments

I'm wondering about one thing, now that I've read a few "may cause issues" and "is used for mDNS" replies: what the F is mDNS actually doing in the background?

Is it really going to assign "lancelot.roundtable.local" to my washing machine on a whim, which leaves the microwave unresolvable?

Can't I instruct the mDNS server running on my machine to respond to a particular name ending in .local?

Can't eg. dnsmasq insert itself into a conversation on 224.0.0.251 saying "Let me answer this question" for certain queries?

I'm a little fuzzy on this, but my understanding is that for mDNS to be reliable it is required that all .local hosts implement mDNS to allow for conflict resolution.
If you’ve set up x.local in your DNS for your dryer but your laptop uses mDNS, it’s possible that your lapatop’s mDNS will get a response from your microwave that it’s reachable at x.local. The solution (not an expert, please check this) is to set up the dryer in DNS as x.domain-thar-you-own or x.home.arpa
Thank Apple for this half-baked bullsh*t.
No. Fuck MS for encouraging their MVPs to use a reserved domain.
How so?
Maybe because of this?

> mDNS implementations

> RFC 6762 was authored by Apple Inc. employees Stuart Cheshire and Marc Krochmal, and Apple's Bonjour zeroconf networking software implements mDNS. That service will automatically resolve the private IP addresses of link-local Macintosh computers running MacOS and mobile devices running iOS if .local is appended to their hostnames. In addition, Bonjour devices will use those .local hostnames when advertising services to DNS Service Discovery clients.

> Most Linux distributions also incorporate and are configured to use zeroconf.

> ..The connection of Macintosh and Linux computers or zeroconf peripherals to Windows networks can be problematic if those networks include name servers that use .local as a search domain for internal devices.

https://en.wikipedia.org/wiki/.local

Kinda weird to blame the people who made an RFC, instead of the industry leader who recommended using .local completely on their own, without support from the wider industry. This is explained in the next couple paragraphs, where you stopped copying.
You're right, the confusion about the use of .local domain seems to be more due to Microsoft going back-and-forth about it.

> At one time, Microsoft at least suggested the use of .local as a pseudo-TLD for small private networks with internal DNS servers.

> ..However, more recent articles have cautioned or advised against such use of the .local TLD.

> Microsoft TechNet article 708159[7] suggested .local

> ..but later recommended against it.

> The Microsoft Learn article "Selecting the Forest Root Domain"[8] cautioned against using .local

> By default, a freshly installed Windows Server 2016 Essentials also adds .local as the default dns-prefix when a user doesn't select the advanced option, resulting in a domain with .local extension.

mDNS was announced after the Windows 2000 RTM date, so it would be unfair to blame Microsoft with regards to mDNS functionality.

Not that Microsoft should have made that recommendation, but hindsight and all that.