Host = domain

[Joseph S D Yao]

On Wed, Jul 19, 2006 at 06:56:36PM +0200, Okka Dns wrote:
> 
> Works for me.
> Using bind 9.2.3 
...
> > www	A	@ 
...


I was going to cite where in the ARM this wasn't possible, but ... I
just grepped through the ARM and "@" is a completely undocumented
feature.  ;-)  Which nevertheless everyone knows and uses.

Cricket Liu's "DNS and BIND" doesn't have "@" in the index!  But it's in
Chapter 4, p. 68 of the Fifth Edition [you have gotten your 5e, right?
;-)].  Here it says that the domain name [the left-hand side] may be
specified as "@" if it's the same as the origin.  It says NOTHING about
it being usable as the right-hand side; but even if we for the moment
accept the possibility of it being in the RHS, that would mean that the
above says:

www	A	domain.tld

which is still illegal, as the domain is not the IP address.

Besides, any resource records for "www" do NOT affect the resource
records for the domain itself!  The above does not do what the original
poster wanted.

Several people have already commented that:

@	A	ip.ad.dr.ess

will work, and so it will.  But the original poster was ALSO correct
that the following should work:

{empty space}	A	ip.ad.dr.ess

... but ONLY when this follows something else whose LHS is the origin
domain!  In other words, THIS will work:

$TTL	24h

@	SOA	...

	NS	...
	NS	...

	A	ip.ad.dr.ess

www	A	ip.ad.dr.ess

but the following will only generate TWO identical "A" records for
"www":

$TTL	24h

@	SOA	...

	NS	...
	NS	...

www	A	ip.ad.dr.ess

	A	ip.ad.dr.ess

and the following generates an extra, incorrect A record for "foo":

$TTL	24h

@	SOA	...

	NS	...
	NS	...

www	A	ip.ad.dr.ess
foo	A	other.ip.addr.ess

	A	ip.ad.dr.ess

-- 
Joe Yao
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