[dns-operations] creeping poorness of judgement
paul at redbarn.org
Sat Mar 14 03:04:15 UTC 2020
oh my great goodness. in RFC 7208 we have this:
3.3. Multiple Strings in a Single DNS Record
As defined in [RFC1035], Sections 3.3 and 3.3.14, a single text DNS
record can be composed of more than one string. If a published
record contains multiple character-strings, then the record MUST be
treated as if those strings are concatenated together without adding
spaces. For example:
IN TXT "v=spf1 .... first" "second string..."
is equivalent to:
IN TXT "v=spf1 .... firstsecond string..."
TXT records containing multiple strings are useful in constructing
records that would exceed the 255-octet maximum length of a
character-string within a single TXT record.
note the lack of a space between the word "first" and the word "second".
> ;; ANSWER SECTION:
> _spf.tisf.net. 120 IN TXT "v=spf1" "ip4:188.8.131.52/24" "ip6:2001:4f8:3::/48" "ip4:184.108.40.206/24" "ip6:2001:559:8000::/48" "-all"
is going to get most of my mail bounced, or something. in the zone file
this looks pretty different:
> _spf TXT ( v=spf1
> ip4:220.127.116.11/24 ip6:2001:4f8:3::/48
> ip4:18.104.22.168/24 ip6:2001:559:8000::/48
> -all )
if anybody is within shouting distance of joe abley, tell him i probably
can't answer his hopcount.ca e-mail any more. yes, i know that some name
server implementations break strings at 255-character blocks. i fixed
that in BIND 4.9 back in 1992. a correct name server interprets a zone
file having ( and ) as shown.
"creeping poorness of judgement" means that in internet standards, as
with autonomous vehicles, it's nobody's fault when a crash happens.
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