[sf-lug] DNS & ns1.svlug.org - RNAME squashed to lowercase(!) (interesting, but NOT critical!)

Michael Paoli Michael.Paoli at cal.berkeley.edu
Thu Sep 26 03:39:41 PDT 2019


DNS & ns1.svlug.org - RNAME squashed to lowercase(!) (interesting, but  
NOT critical!)

Interesting, but NOT critical! ... I notice:
sf-lug.net. 172800 IN SOA ns0.sf-lug.net.  
michael\.paoli.cal.berkeley.edu. 1568756554 10800 3600 1209600 86400  
@64.62.190.98 (ns1.svlug.org.)
sf-lug.net. 172800 IN SOA ns0.sf-lug.net.  
michael\.paoli.cal.berkeley.edu. 1568756554 10800 3600 1209600 86400  
@2600:3c01::f03c:91ff:fe96:e78e (ns1.svlug.org.)
sf-lug.com. 172800 IN SOA ns0.sf-lug.com.  
michael\.paoli.cal.berkeley.edu. 1568756586 10800 3600 1209600 86400  
@64.62.190.98 (ns1.svlug.org.)
sf-lug.com. 172800 IN SOA ns0.sf-lug.com.  
michael\.paoli.cal.berkeley.edu. 1568756586 10800 3600 1209600 86400  
@2600:3c01::f03c:91ff:fe96:e78e (ns1.svlug.org.)
berkeleylug.com. 172800 IN SOA ns0.berkeleylug.com.  
michael\.paoli.cal.berkeley.edu. 1569330375 21600 3600 1209600 86400  
@64.62.190.98 (ns1.svlug.org.)
berkeleylug.com. 172800 IN SOA ns0.berkeleylug.com.  
michael\.paoli.cal.berkeley.edu. 1569330375 21600 3600 1209600 86400  
@2600:3c01::f03c:91ff:fe96:e78e (ns1.svlug.org.)
berkeleylug.org. 172800 IN SOA ns0.berkeleylug.org.  
michael\.paoli.cal.berkeley.edu. 1569187696 10800 3600 1209600 86400  
@64.62.190.98 (ns1.svlug.org.)
berkeleylug.org. 172800 IN SOA ns0.berkeleylug.org.  
michael\.paoli.cal.berkeley.edu. 1569187696 10800 3600 1209600 86400  
@2600:3c01::f03c:91ff:fe96:e78e (ns1.svlug.org.)

On the master(s), for SOA, RNAME is:
Michael\.Paoli.cal.berkeley.edu.
whereas on slave ns1.svlug.org it's:
michael\.paoli.cal.berkeley.edu.
So ... those are respectively interpreted as email addresses:
Michael.Paoli at cal.berkeley.edu
and:
michael.paoli at cal.berkeley.edu
Now, per RFC(s), Internet @ type email addresses,
the localpart (part before @) is recommended, but not required,
to be treated as case insensitive ... but if I'm not mistaken, it's
also recommended that case be preserved.
And DNS ... for the most part, in general, is mostly case insensitive,
but also generally case preserving.  Seems slightly odd to me
(and perhaps hair less than ideal) that the DNS software on ns1.svlug.org.
apparently squashes that to lowercase.
However, in at least this particular case, doesn't particularly matter
for the data at hand - as the MTAs/mail servers handling that particular
email address, treat the localpart as case insensitive (at least for
matching/processing) ... though I think they also preserve case on it.
... I wonder if that DNS server software has a configuration option
to not squash that data to lowercase.
Also, email - the domain portion is case insensitive - both per DNS
matching and per relevant email RFC(s) - so the
@cal.berkeley.edu portion doesn't matter at all as to case - at least
in terms of functionality (various processing bits may opt to preserve
the case or generally do so, but of no other consequence for that portion
other than possibly cosmetic/appearance).




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