[BlueOnyx:22319] Re: DNS

[neal pressman]

i ran into this a week ago for a 1 off request from a customer who needed 
an "_" to use some 3rd party email service.

i just added it to the db.domain.name.include file be hand

--
Open WebMail Project (http://openwebmail.org)


---------- Original Message -----------
From: Michael Stauber <mstauber at blueonyx.it>
To: blueonyx at mail.blueonyx.it
Sent: Mon, 13 Aug 2018 14:02:19 -0500
Subject: [BlueOnyx:22318] Re: DNS

> Hi Colin,
> 
> > I have been asked by a client to create a new CNAME record on the DNS
> > for the following:
> > 
> > NEW Record Type: CNAME
> > 
> > Hostname: _69F8BF440B0DA58166380745E0EB4F5F.domain.co.uk
> > 
> > Point to:
> > 
57BB458482A5AB33474E97891351014E.E610BBD363C7C2E032B35DDA755B2B52.55WcQD58
V50sJqcKeKP5.comodoca.com
> > 
> > Bind says no! :-/
> > 
> > It won’t accept either of the host names using the GUI and adding it 
to
> > the include file causes an error.
> The regular expressions that the GUI uses to validate input type
> "hostname" is like this:
> 
> <typedef name="hostname" type="re"
> 
> data="^(([a-z0-9]|[a-z0-9][a-z0-9\-]*[a-z0-9])\.)*([a-z0-9]|[a-z0-
> 9][a-z0-9\-]*[a-z0-9])$"
> 
> />
> 
> So ... no upper case characters and no leading "_". Granted, we're a 
> bit more strict there than RFC 952 and RFC 1123, which say that the 
> characters are case insensitive. Meaning: Put a big "A" there or a small
> "a" and it doesn't matter. Both are treated as the same.
> 
> Still: The fact remains that host- and domain names (according to 
> RFC) may not start with anything *but* a character or (as of RFC 
> 1123) a number. Hence: The underscore is a total no-no.
> 
> Unless you're talking domain keys (which are deprecated anyway) or 
> SRV records.
> 
> I guess what your client really wants is either a CAA-record or a
> SRV-record and not a C-name?
> 
> -- 
> With best regards
> 
> Michael Stauber
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> Blueonyx at mail.blueonyx.it
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------- End of Original Message -------