how to overcome underscore in A record

[Mark Andrews]

> You can do:
> this-machine in A 123.2.234.4
> this_machine in CNAME this-machine.somedomain.com.
> _ are allowable in CNAMEs because the RFC doesn't consider them "hostnames",

	Incorrect.  RFC 952 says that both aliases (CNAME owners)
	and the offical names need to be meet the same syntax rules.

	CNAMEs are not checked by named because they can point to
	types other than A or AAAA.  Additionally CNAMEs can point
	outside of the zone making it almost impossible to do the
	check when loading the zone.

	One could always add post-load checks of CNAME records to
	ensure that CNAME owners that fail to meet the host name
	rule don't point to A or AAAA records.


> but in the end getting rid of the _ all together is probably the best
> choice.

	Agreed.

> On Sun, Aug 24, 2008 at 11:18 PM, PM Wong <s11976 at net1.hkbu.edu.hk> wrote:
> 
> > We've been using the older version (pre 9.3)
> > and the underscore in the hostname in A recored
> > like
> > this_machine IN A 123.2.234.4
> >
> > is okay.
> > We have to upgrade the bind to 9.5
> > The new version does not like underscore in the hostname
> >
> > Is there any way to workaround ?
> > (otherwise we have to re-publish the web site URL
> > with a new one
> > as the user has used the underscore in its web site
> > for quite some time)
> >
> >
> 
> 
> -- 
> -Ben Croswell
> 
> 
> 
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org