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Comment by upofadown | Hacker News Reader

FWIW, the OpenBSD resolve.conf(5) man page says:

>If there are multiple servers, the resolver library queries them in the order listed.

That's the same in FreeBSD:

> (The algorithm used is to try a name server, and if the query times out, trythe next, until out of name servers, then repeat trying allthe name servers until a maximum number of retries are made).

So it seems there is a de facto standard for the default libraries in some *NIX OSes?

Confirmed in Solaris 10 and Solaris 11 as well.

No. All that it is is common heritage in the BIND DNS client library whose doco this is. It is a widely used DNS client library that has made it into numerous operating system's C libraries, from Solaris through GNU libc to OS/2. The manual pages for that library have spread along with it.

* https://www.isc.org/downloads/libbind/

* http://wiki.netbsd.org/individual-software-releases/netresol...

* https://sourceware.org/git/?p=glibc.git;a=blob;f=resolv/READ...

One can even trace its spread from, say, 386BSD through NetBSD to OpenBSD.

* https://github.com/NetBSD/src/blob/516da8a02fc8bc10555ed9acd...

* https://github.com/openbsd/src/blob/df930be708d50e9715f173ca...

Manual pages are not standards, not specifications, but implementation documentation. As Chuck McManis said in this very discussion, to misuse them as standards or specifications is to mistakenly treat implementation as architecture.

The BIND DNS client library is far from the only DNS client library in existence. Other DNS client libraries read /etc/resolv.conf, as part of a BIND DNS client compatibility shim or otherwise. They do not have the same implementation details as the BIND DNS client; they do not all have the same access patterns as the BIND DNS client. Indeed, as I have mentioned elsewhere in this very discussion, even other tools from the same origin, namely nslookup, read /etc/resolv.conf and have different access patterns.

* https://cr.yp.to/djbdns/blurb/library.html

* http://www.chiark.greenend.org.uk/~ian/adns/

* http://25thandclement.com/~william/projects/dns.c.html

* https://groups.google.com/d/msg/comp.protocols.dns.bind/B3tg...

There is not a single common conventional, let alone standard, behaviour to rely upon.

The complaint isn't that the new behaviour is not compliant with some standard. It is that the change is arbitrary and pointless.

None of your links contain the text "resolve.conf".

Nslookup is an end user diagnostic tool and would not be expected to conform to any standard, even if there was one.

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