reasonable length of FQDN

[Mark Andrews]

> In article <drphne$cog$1 at sf1.isc.org>,
>  Roman Mashak <romez777 at gmail.com> wrote:
> 
> > Hello,
> > 
> > what may be the reasonable length of fully-quialilfied domain name
> > that can be set up in application? I'd wish this length would cover
> > possible user desires and at the same time wouldn't violate standard.
> 
> 255 characters assuming one octet per character. 
> 
> http://www.ietf.org/rfc/rfc2181.txt
> 
>    The DNS itself places only one restriction on the particular labels
>    that can be used to identify resource records.  That one restriction
>    relates to the length of the label and the full name.  The length of
>    any one label is limited to between 1 and 63 octets.  A full domain
>    name is limited to 255 octets (including the separators).

	Well the DNS can only support hostnames up to 253 octets.
	Note a hostname does not have a period at the end (RFC 952).

	The same limits apply to mail domains in the DNS for the
	same reasons.
 
> -- 
> Christian Smith
> Dynamic Network Services, Inc.
> 
> 
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org