Are underscores no longer supported in Bind 9.4?

Tony Earnshaw tonni at
Thu Mar 1 03:30:46 UTC 2007

Mark Andrews wrote, on 01. mar 2007 01:45:

>> Does bind 9.4 no longer support underscores (_) in the A records?
>> I know I have these in many records in versions before 9.4.
>> Here is the error that I am getting now.
>> Feb 28 18:29:54 t141 named[8767]:
>> bad owner name (check-names)
>> As soon as I remove the A record with the underscore it in, everything is
>> fine and the zone loads.
>> Is this a new rule / RFC?
> 	No.  It's a 20 year old rule.  See RFC 952 and RFC 1123.
> 	The later extends the syntax to allow leading digits.
> 	Labels in hostnames are restricted to letters, digits and
> 	hypens (LDH).
> 	If you really want underscore you can turn the checks off
> 	however I suggest that you rename the machines as there are
> 	resolver libraries which check.

Haven't begun with 9.4 yet, but shall do shortly. Are underscores 
permitted in TXT records? I'm thinking of things like Kerberos and 
Domainkeys/DKIM TXT records.


Tony Earnshaw
Email: tonni at hetnet dot nl

More information about the bind-users mailing list