[irusensei]

Not surprised. They used to have training material incentivizing professionals to use .local as TLD for Active Directory realms. Thats a reserved domain for Multicast DNS.

Working on Linux automation systems we would need to make sure to disable anything related to Avahi in our images otherwise name resolution would fail for some customers.

[ndriscoll]

Haven't they been telling people to do that since before it became reserved? If so, the problem is more that you can't "reserve" something that's already in wide use, and mdns should've used something like .mdns.

It's like when .dev became a gTLD, knowingly breaking a bunch of setups for a mix of vanity and a cash grab. Obviously dropped the ball on the engineering side.

[WorldMaker]

Seems more a reason to never use stuff you don't actually control and are reserved for future purposes. Everyone knew who was in charge of DNS TLDs and that while they were being at first conservative in how many they assigned, they reserved the right to assign as many as they wanted.

But also, yes Microsoft documentation used .local before mDNS reserved it, and IIRC Microsoft was also involved in suggesting it for mDNS as mDNS came out of the multi-company standardization efforts from Apple's Bonjour. That said, my impression of most of that documentation from that time is that it was incorrectly using .local as a fake TLD where they should have been using .example or .example.com and also pointing people to the RFCs that those were not valid choices in a real setup. A problem with such documentation is that it is too easy to take literally. A follow up problem was sort of the "accidental security through obscurity" benefits of using non-globally resolvable addresses becomes "best practice" through essentially stubbornness and status quo (related to all the recent rediscussions on HN about NAT44 is not a firewall except by accident and you can have very good firewalls that aren't NAT44).

[justsomehnguy]

> Haven't they been telling people to do that since before it became reserved

If you actually try to find an evidence for this (even time traveling to 2015 before the great wipe of most pre-Vista docs) you wouldn't find a confirmation for this. What you would find is what the official docs always recommended the root domain to be an official bought one on the public internet. And this excludes .local.

[szszrk]

My company used .local for EVERYTHING. I took it as normal at the time, until I got into problems with VMWARE products.

Support patiently explained .local is reserved for something else and kindly provided Wikipedia links.

They never responded why they used .local in their docs, trainings, webinars they provided, though :)

[EvanAnderson]

Things from docs making it into production is insidious. There were some early Sun docs that referenced a 129.9.0.0/16 network. Some helpful contractor in my locality, specializing in local government work, configured several police, fire, and city governments with that subnet internally back in the 90s. A few of them are still running that way today. I remember running into some oddball behavior with the Teredo adapter in Windows 7 that I traced back to it behaving differently because the PC's IP address didn't fall into RFC1918 space.

[PcChip]

I’ve worked with hundreds of customers that use .local internal domains and vmware, what issues are you describing?

[irusensei]

My impression is that Ballmer IE6 era Microsoft didn't gave a shit about standards.

[p_ing]

Usage of .local for AD predated mDNS. That advice stopped with the advent of mDNS in favor of 'corp.<registered_domain>.<tld>'.

[EvanAnderson]

The original Windows 2000 guidance for AD was corp.example.com, from my recollection. The silly .local thing (which does predate mDNS) happened as a result of the Small Business Server refresh for Active Directory.