Sites that points their A Record to localhost

Joseph S D Yao jsdy at tux.org
Sat Jan 11 04:36:07 UTC 2014


On 2014-01-10 15:01, Eduardo Bonsi wrote:
...
> It seems like they have their domain configuration A Record pointed
> to the localhost. We all know that the localhost is not routable
> outside of the internet. Therefore I am sure their website cannot
> resolve out of the 127.0.0.1.
> In addition to that, it is possible that this is happening only here
> because of the way our Server configuration is setup in the OS X to
> bring the resolver to the localhost first before it can go out to the
> distributed domains/websites through the Apache conf.
...


There seems to be a pile of misconceptions here.

(1) There is no requirement at all that a domain name have an A record. 
It does not have to resolve to an IP address at all.  It only has to 
have an SOA record and an NS record (preferably more than one); and not 
even that, if it is a subdomain that is not a separate zone.

(2) There is no requirement that a domain name refer to the Web site 
for that domain.  I personally don't like that (for no special reason), 
and neither apparently does the owner of this domain, who forces people 
to go to the trouble of typing in www.p3net.net to get to his or her Web 
site.  Incidentally, there is no requirement that the domain name refer 
to a mail server, either (which used to be common before the Web 
existed), or to an FTP server, or to a Telnet server, or to a nuclear 
reactor control device.  Or to anything.

(3) However, any name MAY resolve to any IP address, routable or not.  
That doesn't mean there's anything useful, or even related to that 
domain, at that IP address.

(4) "127.0.0.1" is the IP equivalent of the English language word "me". 
If I say, "me", I am referring to myself.  If you say, "me", you are 
referring to yourself.  It cannot be used to direct anyone to somewhere 
else.  In fact, some use it to deflect probers AWAY from themselves, and 
back on the prober's own server.  (E.g., if I wanted to probe 
"p3net.net", my server would be probing itself!)

(5) 127.0.0.1 is not among the IP addresses mislabeled as "unroutable". 
It is always routable.  To right here.  Well, for you, right there.

(6) Just because OS X has 127.0.0.1 as the resolver has no effect on 
what that resolver returns.  Don't confuse the concepts.

I think there were some others, but it's getting late.

Joe Yao


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