>A few Penguinistas spent a weekend working out why they can't get through to Netflix from their Linux machines, because when they tried, their DNS lookups failed.
https://www.theregister.co.uk/2017/07/24/underscore_domain_name_bug/
>Penguinistas
>netflix
>>61549719
temporary patch https://github.com/keszybz/systemd/commit/0926f34
issue https://github.com/systemd/systemd/issues/6426#issuecomment-317203834
>>61549719
>netflix
How bad is the quality control at Red Hat/systemd?
>>61549719
>systemd on gentoo
served him right
>>61550285
how about you stop bitching about proprietary shit
>inb4 muh gnu
>>61549719
does anybody know of a domain name with _ in it?
>DNS resolver in PID 1
Surely this cannot go wrong in any way.
>>61549719
Underscores aren't valid characters in DNS hostnames. The external library systemd uses (libidn2) responds correctly to spec by not processing the invalid request.
So it's not a bug and not part of systemd.
>https://www.ietf.org/rfc/rfc1035.txt
>RFC1035 - DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
>section 2.3.1 - any one of the 52 alphabetic characters A through Z in
upper case and a through z in lower case... any one of the ten digits 0 through 9
Its an invalid character sempai.
Granted, it COULD be used in private domains on custom DNS software, seemingly the '_' character shouldnt be recognized as a valid character for public DNS lookups.
Can anyone give an example of a site that actually uses '_' in its domain?
>>61549719
What was Poettering's snarky reply?
>>61550476
>Can anyone give an example of a site that actually uses '_' in its domain?
ipv6_1-cxl0-c088.1.lhr004.ix.nflxvideo.net
Let me quote few lines from the 10 year younger RFC on DNS:
>any binary string whatever can be used as the label of an resource record.
>Implementations of the DNS protocols must not place any restrictions on the labels that can be used
So, not only is _ fine but so are things like Яндeкc.pф or sää.fi for example. I don't have PoetteringDNS so I can't test if it fails on those too or was _ just a special character that caused it to NOT-A-BUG/WONT-FIX
>>61551004
interesting. Which rfc is this?