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Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN?

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On 10/20/15 14:52, Lew Pitcher wrote:
> On Monday October 19 2015 13:37, in comp.os.linux.networking, "William Unruh"
> <unruh@invalid.ca> wrote:
>
>> On 2015-10-19, Joe Pfeiffer <pfeiffer@cs.nmsu.edu> wrote:
>>> William Unruh <unruh@invalid.ca> writes:
>>>
>>>> On 2015-10-19, Richard Kettlewell <rjk@greenend.org.uk> wrote:
>>>>> Baho Utot <baho-utot@columbus.rr.com> writes:
>>>>>> On 10/18/15 17:25, Richard Kettlewell wrote:
>>>>>>> Baho Utot <baho-utot@columbus.rr.com> writes:
>>>>>>>> On 10/18/15 14:32, Richard Kettlewell wrote:
>>>>>>>>> This is nonsense.  www.google.com is a domain name.  See RFC1034 for
>>>>>>>>> terminology.
>>>>>>>>
>>>>>>>> google.com is the domain name.
>>>>>>>>
>>>>>>>> www.google.com is a host name.
>>>>>>>>
>>>>>>>> www.google.com is NOT a domain name, that non-sense started with web
>>>>>>>> masters/devs.
>>>>>>>
>>>>>>> Obviously you didn???t follow the suggestion to see RFC1034.
>>>>>>>
>>>>>> Obviously you didn???t understand RFC1034
>>>>>
>>>>> s3.1 is pretty clear about the definition of ???domain name???.  Which
>>>>> part do you think contradicts it?
>>>>
>>>> As I understand it, for you there domain name encompasses host name. A
>>>> host name
>>>> is also a domain name. For some people a
>>>> distinction is nice, and the word "domain name" differs in that a domain
>>>> name normally implies that there are a number of host names associated
>>>> with it, and a hostname refers (usually) to a single computer/ip, while
>>>> a domain name encompasses a whole buch of host names. Anyway, that was
>>>> the sense in which I interpreted the term "domain name". If it is not
>>>> the sense in which the OP used the term, I apologize.
>>>> Getting bogged down in semantics rarely leads to fruitful discussions.
>>>
>>> It isn't that a domain name is necessarily also a host name, it's that
>>
>> No I am saying that a host name is necessarily also a domain name, seems
>> to be that point of the dispute.
>>
>>> the RFC allows it to be.  You may prefer that administrators never have
>>> a host with the same name as the domain, but that isn't going to stop
>>> them from doing it.
>>
>> You mean like physics.ubc.ca which is a host name and
>> info.physics.ubc.ca which is also a host name.
>>
>> I am willing to accept that physics.ubc.ca is both a hostname and a
>> domain name, but info.physics.ubc.ca is a host name only. The
>> interpretation of RFC1034 appears to be that info.physics.ubc.ca is also
>> a domain name. Not can be, but is.
>
> It is (to me) easier to understand the domain name system if I divorce it
> from "host"s and "IP address"es.
>
> RFC1034 describes names as abstract entities, analogous (to me) to file
> pathnames.
>
> Think of the /usr unix path hierarchy, for instance.
>    /usr
> is a pathname. The thing that
>    /usr
> describes has (or lacks) certain attributes (filesize, permission bits, etc).
> That it has (or lacks) these attributes doesn't invalidate the designation
> of /usr as a pathname.
>
> But, under this, there is more
>    /usr/local
> is also a pathname. The thing that
>    /usr/local
> describes has (or lacks) certain attributes (filesize, permission bits, etc).
> That it has (or lacks) these attributes doesn't invalidate the designation
> of /usr/local as a pathname.
>
> Additionally, that
>    /usr/local
> is a pathname doesn't invalidate
>    /usr
> as a pathname either.
>
> And so on, through
>    /usr/local/src
> to
>    /usr/local/src/flite-2.0.0-release/include/flite.h
>
> Each step results in a pathname, and a node that has (or lacks) certain
> attributes.
>
> Similarly, the Domain Name System defines a "pathname", which they call
> a "domain name". Each refinement of "domain name" results in another "domain
> name". And, each "domain name" has (or lacks) certain attributes (mail
> exchanger, IP address, Chaosnet address, Hesiod address, etc).
>
> Thus
>    com
> is a domain name, which lacks most attributes (including IP address). And
>    google.com
> is a domain name, which has multiple IPV4 addresses, a single IPv6 address,
> and multiple mail exchanges. And
>    www.google.com
> is /also/ a domain name, and also has multiple IPV4 addresses, and a single
> IPv6 address.
>
> HTH
>

You might hear the term Fully Qualified Domain Name (FQDN) and become 
confused because that term seems to imply that something like 
bob.accounting.bobsemployer.com is a domain name instead of a hostname. 
I think that the term should have been called Fully Qualified Domain 
Hostname or maybe Fully Qualified DNS Name, because in the FQDN term, 
Domain Name doesn't mean "domain name" like bobsemployer.com, it means 
"the name on the domain", so the term can be misleading, although its 
used in many official documents and program descriptions just by rote.

On the public part of the Internet, we all utilize a DNS infrastructure 
that use global top level domains like .com, .net, .org, .us, .fr, etc. 
Then people can purchase or accquire domains on those gTLDs such as 
bobsdomain.com. Then we often see hostnames like www.bobsdomain.com or 
blog.bobsdomain.com used under that. These are actually called logical 
hostnames because usually they are just names pointing at a single host. 
Often times the host they are pointing to has its own hostname called 
whatever the owner wants to call it, like myrtle.bobsdomain.com.

Probably a lot of the confusion came about because some web hosting 
companies started calling hostnames like blog.bobsdomain.com subdomains, 
where they are not. blog.bobsdomain.com is only a sub domain if there 
are DNS records underneath it, like mary.blog.bobsdomain.com.

For the most part, you can simply follow this rule "domains encapsulate 
hostnames". Most people don't need to think about what DNS zones are, 
just leave that to DNS administrators. Resources on the network 
generally don't care or even know what their hostnames are or what 
hostnames might be pointing to them. They are mostly there for human 
reference and ease of use of the network.

For example, the hostname www.toyota.com refers to a World Wide Web 
server named "www" in the toyota.com domain (the network associated with 
the Toyota automotive company). The hostname ftp.stanford.edu refers to 
an FTP server named "ftp" on Stanford University's local network (the 
domain stanford.edu)


hostname is the name given to the end-point (the machine in question)
         and will be used to identify it over DNS if that is configured
     domain is the name given to the 'network'
         it will be required to reach the network from an external point 
(like the Internet)

It is usually written in the form,

     hostname.domain.com -- for example

If you are in (say) a college campus named called 'The-University',
and its domain is called 'theuniversity.org',
a machine on the campus network called 'mymachine' would be addressed 
as, 'mymachine.theuniversity.org'.

If you were trying to connect to this machine from your home network,
you would address it with that full name.
The domain part would reach you to the campus network
and the hostname would let you reach the exact machine in the campus.
I am avoiding the details of IP Addressing and gateways here.

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Thread

Is it possible to obtain all of the ip addresses correspoding to a FQDN? Hongyi Zhao <hongyi.zhao@gmail.com> - 2015-10-18 01:43 +0000
  Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Bit Twister <BitTwister@mouse-potato.com> - 2015-10-18 03:27 +0000
  Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Marc Haber <mh+usenetspam1118@zugschl.us> - 2015-10-18 09:45 +0200
    Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Richard Kettlewell <rjk@greenend.org.uk> - 2015-10-18 12:43 +0100
      Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Marc Haber <mh+usenetspam1118@zugschl.us> - 2015-10-18 17:02 +0200
        Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-18 18:17 +0000
          Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Marc Haber <mh+usenetspam1118@zugschl.us> - 2015-10-18 20:30 +0200
            Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Richard Kettlewell <rjk@greenend.org.uk> - 2015-10-18 19:35 +0100
  Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? William Unruh <unruh@invalid.ca> - 2015-10-18 17:31 +0000
    Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-10-18 13:48 -0400
      Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? William Unruh <unruh@invalid.ca> - 2015-10-18 18:22 +0000
        Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Richard Kettlewell <rjk@greenend.org.uk> - 2015-10-18 19:32 +0100
          Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-18 16:45 -0400
            Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-10-18 17:14 -0400
              Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-18 19:09 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-10-18 20:22 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-10-18 20:41 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Rick Jones <rick.jones2@hp.com> - 2015-10-19 20:56 +0000
            Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Richard Kettlewell <rjk@greenend.org.uk> - 2015-10-18 22:25 +0100
              Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-18 19:04 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Richard Kettlewell <rjk@greenend.org.uk> - 2015-10-19 09:22 +0100
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? William Unruh <unruh@invalid.ca> - 2015-10-19 16:55 +0000
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2015-10-19 11:23 -0600
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? William Unruh <unruh@invalid.ca> - 2015-10-19 17:37 +0000
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-10-20 14:52 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-20 18:45 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? William Unruh <unruh@invalid.ca> - 2015-10-21 01:47 +0000
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-21 18:43 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-21 10:54 +0000
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-21 18:38 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Marc Haber <mh+usenetspam1118@zugschl.us> - 2015-10-22 08:57 +0200
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Baho Utot <baho-utot@columbus.rr.com> - 2015-10-22 19:36 -0400
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-10-23 17:44 +0000
                Re: Is it possible to obtain all of the ip addresses correspoding to a FQDN? Marc Haber <mh+usenetspam1118@zugschl.us> - 2015-10-23 21:21 +0200

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