Inet Domain Questions, Please Assist. - TCP-IP

This is a discussion on Inet Domain Questions, Please Assist. - TCP-IP ; What exactly is a registerable Internet domain name and how does that relate to subdomains? For instance if one owns or is renting? xyzabc.com then what exactly is jkl.xyzabc.com? I understand that the jkl is known as a subdomain. But ...

+ Reply to Thread
Results 1 to 5 of 5

Thread: Inet Domain Questions, Please Assist.

  1. Inet Domain Questions, Please Assist.

    What exactly is a registerable Internet domain name and how does that relate
    to subdomains? For instance if one owns or is renting? xyzabc.com then
    what exactly is jkl.xyzabc.com? I understand that the jkl is known as a
    subdomain. But is the complete entity jkl.xyzabc.com something that is
    independently registerable from xzyabc.com? OR if one owns xyzabc.com then
    does one own automatically all
    subdomains off xyzabc.com in Internet domain name space? I guess the
    question boils down to whether '.' is a special and non-registerable
    character below the TLD level and therefore the registerable domain name is
    that entity in the right most portion of the name including one and only one
    '.' which preceeds a valid TLD?




  2. Re: Inet Domain Questions, Please Assist.

    "Ron Reaugh" wrote in message news:...
    > What exactly is a registerable Internet domain name and how does that relate
    > to subdomains? For instance if one owns or is renting? xyzabc.com then
    > what exactly is jkl.xyzabc.com? I understand that the jkl is known as a
    > subdomain. But is the complete entity jkl.xyzabc.com something that is
    > independently registerable from xzyabc.com? OR if one owns xyzabc.com then
    > does one own automatically all
    > subdomains off xyzabc.com in Internet domain name space? I guess the
    > question boils down to whether '.' is a special and non-registerable
    > character below the TLD level and therefore the registerable domain name is
    > that entity in the right most portion of the name including one and only one
    > '.' which preceeds a valid TLD?



    You're making this way too complicated. If we had a.b.c.com, a is a
    subdomain of b.c.com, b is a subdomain of c.com, and c is a subdomain
    of com. Technically com is a subdomain of the root, but it's rare to
    call it that, usually .com is just called a top-level-domain (TLD).

    In short, ownership propagates down the domain tree. The "owners" of
    the .com domain have pretty much complete say as to what will happen
    within that domain. They've "chosen" to sell/rent subdomains, hence
    you can send Network Solutions $20 and get ronreaugh.com registered to
    you. If you then choose to sell subdomains to ronreaugh.com, for
    example if you sold fred.ronreaugh.com to Fred, that's between you and
    Fred. You'd have to set up your name server (the one for
    ronreaugh.com) to either resolve fred.ronreaugh.com, or point to
    Fred's name server and let it resolve it. Fred could then sell
    subdomains to fred.ronreaugh.com. And of course you might well have
    internal subdomains.

    Of course there may be contractual restrictions on further delegations
    (eg. your contract with Fred might state that he may not, in fact,
    sell subdomains), but that doesn't change the physical aspects.

  3. Re: Inet Domain Questions, Please Assist.

    "Ron Reaugh" wrote:
    > xyzabc.com then what exactly is jkl.xyzabc.com? I understand that
    > the jkl is known as a subdomain


    And xyzabc.com. is a subdomain of com., and com. is a subdomain of
    .. (the root).

    > But is the complete entity jkl.xyzabc.com something that is
    > independently registerable from xzyabc.com?


    Not independently, no. You might be able to register it if the owner
    of xyzabc.com. chooses to allow registration, but since you could just
    as easily get your own somethingelse.com domain, there's not much
    point, and so no one has made that sort of registration available,
    AFAIK.

    > OR if one owns xyzabc.com then does one own automatically all
    > subdomains off xyzabc.com in Internet domain name space?


    Yes.

    > I guess the question boils down to whether '.' is a special and
    > non-registerable character


    Sort of. A domain name consists of a series of labels. The labels
    are separated by dots when written for human readers (and often for
    programs as well, though not in the DNS protocol itself). A label can
    contain ".", but then when you write such a domain name, you have to
    come up with some way to indicate that it is a literal "." and not a
    label delimiter.

    So the string "jkl.xyzabc.com." represents the sequence of labels
    "jkl", "xyzabc", "com", "". (Informally, people often leave off the
    last "." and don't think about the final empty label, but in the DNS
    protocol, the empty label is always there.) That sequence of labels
    is a subdomain of the domain which is named by the label sequence
    "xyzabc", "com", "". We can also talk about the label sequence
    "jkl.xyzabc", "com", "". But we would have to write this differently
    - say, as "jkl\056xyzabc.com." - to distinguish it from the first
    case, where "jkl" is a separate label.

    > therefore the registerable domain name is that entity in the right
    > most portion of the name including one and only one '.' which
    > preceeds a valid TLD?


    Some country-code TLDs have subdomains which allow registration of
    third-level subdomains - for example, yahoo.co.uk.

    Registrars probably wouldn't let you register a domain name with a
    label containing ".", but if you register xyzabc.com., then there's
    nothing stopping you from creating subdomain names that have labels
    containing ".", like "ghi\056jkl.xyzabc.com.", as long as your name
    server software supports that.


    paul

  4. Re: Inet Domain Questions, Please Assist.

    prj@po.cwru.edu (Paul Jarc) wrote:

    > > But is the complete entity jkl.xyzabc.com something that is
    > > independently registerable from xzyabc.com?

    >
    > Not independently, no. You might be able to register it if the owner
    > of xyzabc.com. chooses to allow registration, but since you could just
    > as easily get your own somethingelse.com domain, there's not much
    > point, and so no one has made that sort of registration available,
    > AFAIK.


    They have: uk.com and the like from CentralNic, for example.

    --
    Ronan Flood
    working for but not speaking for
    Network Services, University of London Computer Centre
    (which means: don't bother ULCC if I've said something you don't like)

  5. Re: Inet Domain Questions, Please Assist.

    Ron Reaugh wrote:

    > What exactly is a registerable Internet domain name and how does that relate
    > to subdomains?


    Some information on this subject is found in my site:
    http://domains.dan.info/structure/subdomains.html


    --
    == Dan ==
    Dan's Mail Format Site: http://mailformat.dan.info/
    Dan's Web Tips: http://webtips.dan.info/
    Dan's Domain Site: http://domains.dan.info/

+ Reply to Thread