[166566] in North American Network Operators' Group
Re: Reverse DNS RFCs and Recommendations
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Wed Oct 30 18:33:40 2013
Date: Thu, 31 Oct 2013 07:36:20 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: nanog@nanog.org
In-Reply-To: <D27DF53349E1E94AA9599001CC1C718917A523BC@kw2k8.KWAUTO.PRI>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Nolan Rollo wrote:
> RFC draft-msullivan-dnsop-generic-naming-schemes-00.txt states:
> When using IP addresses in host names, their numbers SHOULD be
> separated by '.'s (dots) rather than any meta character such as a '-'
> (dash) and expressed in decimal. Host names SHOULD NOT use the '_'
> (underscore) character, host names for hosts with any form of SMTP
> mail service MUST NOT use the '_' (underscore) character. It is
> preferable to use the IP address in reverse format in the same way
> the the IN-ADDR.ARPA. domain is defined.
That's not correct.
Not all domain names are host names, which is why '_' is allowed
for some domain names such as:
_ldap._tcp.example.com [rfc2782]
However, though rfc1034 specifies;
For example, when naming a mail domain, the user should satisfy
both the rules of this memo and those in RFC-822. When creating
a new host name, the old rules for HOSTS.TXT should be followed.
both of "should" in the rfc should, today, be interpreted as "MUST".
Masataka Ohta
