underscore in A or PTR records

[Reindl Harald]

Am 17.02.21 um 10:41 schrieb ONRUBIA AVILES Carlos (CCS/MST):
> Matus,
> 
> What do you mean with " absolutely no, but since underscore is not valid in hostname as per rfc1123, I don't recomment you to use it in hostnamed" ?

_ is not allowed in hostnames

> I tried with the following configuration in zone " dekil.nl " and bind do not accept it:
> 
> 
> hello_mail2.dekil.nl.         3600    IN      A       81.246.48.28
> 
> I have the following message error:
> 
> Feb 17 10:40:41 dnszone904 named[1633]: /etc/bind/zones/master/dekil.nl:19: hello_mail2.dekil.nl: bad owner name (check-names)
> Feb 17 10:40:41 dnszone904 named[1633]: zone dekil.nl/IN: loading from master file /etc/bind/zones/master/dekil.nl failed: bad owner name (check-names)
> Feb 17 10:40:41 dnszone904 named[1633]: zone dekil.nl/IN: not loaded due to errors

_ is not allowed in hostnames


https://tools.ietf.org/html/rfc1123
2.1  Host Names and Numbers

The syntax of a legal Internet host name was specified in RFC-952 
[DNS:4].  One aspect of host name syntax is hereby changed: the 
restriction on the first character is relaxed to allow either a letter 
or a digit.  Host software MUST support this more liberal syntax.

1. A "name" (Net, Host, Gateway, or Domain name) is a text string up to 
24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign 
(-), and period (.)