name spaces?

  • Thread starter Thread starter Rath
  • Start date Start date
Rath said:
Could u plz explain Namespaces?
Click to expand...

Warning you are going to get some conflicting answers
(if you get enough responses, that is).

A name space is a group of names that are all reachable
from a common parent -- this is the simplest "definition".

In mathematics (and thus computer science), the term
"space" is used for things that can "reach each other"
or which "are reachable from a common starting point."

["Memory space" is used to describe the case where one
program can or cannot touch the memory of another program.
In Win32, each program is in a separate memory space
because they cannot directly touch the memory of, or be
touched by, other programs.]

Many people confuse a "name space" with a name tree;
and it is difficult to tell them apart SOMETIMES if the
tree is indeed separate from other "name spaces" it may
be both.

Examples: The INTERNET is a name space. Every
name in that name space is reachable (by definition)
from the ROOT ("." or DOT) domain down.

If you cannot reach a name from the "." root domain then
it is by definition NOT in "The Internet Name Space" (or
it is misconfigured even though it is supposed to be.)

If you have a private root, or not root at all for you Internal
name tree, i.e., you cannot find it by searching from The
Internet then it would be a private name space.

Notice that this is different from merely having a private
name which may or may not be a private name space --
the terms don't always fit for some deployment designs.

From your internal perspective you may be able to resolve
all names (your private ones and The Internet) but others
(i.e., on The Internet) cannot resolve you private name
tree names since they are not (properly) delegates from
their public parent OR some firewall prevents such
resolution.
 
Rath said:
Could u plz explain Namespaces?
Click to expand...

The root is the root of all namespaces under it, com. is a namespace and
everything under com. is in its namespace, microsoft.com. is a namespace,
that belongs to the com. namespace. The root is at the very top, all other
domains under it are in its name space, com. net. org. are all namespaces,
and considered to be top level domains, a TLD is the highest level anyone
can own, within a given root. But the root is really the top level, even
though it is not called the top level domain.

A lot of people don't know that there a many roots on the internet, some
exclusive, some are inclusive. The difference being that some roots know
more TLDs than others. The ICANN root is the one that most people are
familiar with even if they've never heard of it. I can name off several
roots right off the top of my head, of course there is the ICANN root, which
includes the IANA root, but there is also the ORSC root, the Pacroot, the
Atlantic root, Public root, Unified Root, and the ORSN root just to name a
few and are the most reliable. You could start your own root namespace, but
that doesn't mean anybody but you will use it. The problem is the root
server at some of these roots are not very reliable, no domain in a root is
any more reliable than the root servers in that root. If the root servers
are down, all domains in that root will be down.
Most if not all of these roots can resolve the ICANN Root, but the ICANN
root only resolves a small number of the TLDs in the other roots. So believe
it or not, most people cannot access all of the internet by name because
they use the ICANN root. Some of these roots will let you buy your own top
level domain. For instance, try www.cars.saab in the ICANN root.

What's the point of all these roots?
If a business has a global network that they want excluded by most computers
and don't want to maintain their own root servers they can get a TLD in one
of these roots, have global resolution with a name 99% of the worlds
computers cannot access by name.
 
In
Rath said:
Could u plz explain Namespaces?

Thanx in Adv.
Click to expand...

I feel namespaced-out after these other fine responses to your question. At
least you now know what a namespace is by definition and the reason why this
is a broad term and depends really in what context you mean. But let's add
to the confusion...

If you are thinking in AD terms as to what to call your "namespace" or the
AD domain's start of it's namespace, then the rules and definitions apply,
but we can stretch them. If I have an AD domain called example.com with no
children (sub domains), then I can say that's my AD's infrastructure's
domain name and it's namespace. At the same token, I can create a totally
different tree in the forest called example.com. It's a different namespace.

You know what is strange as well, let's say forest1's namespace starts at
example.com. THen I install and promote a new server in a whole new forest
called forest2, and it has nothing to do with forest1, and create the very
first domain in the new forest called "sub.example.com", and even though
forest1's name there is already in forest1 that existing "example.com" zone,
then that would be a totally different namespace because I arbitrarily made
it that way as far as AD is concerned. It's like two private domains on the
same LAN and they can actually use the same DNS server, even though it will
look like it's all one namespace in DNS, it's really two logically different
namespaces in Active Directory.

--
Ace

This posting is provided "AS-IS" with no warranties or guarantees and
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If you are having difficulty in reading or finding responses to your post,
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Express or any other newsreader of your choosing), and configure a newsgroup
account, pointing to news.microsoft.com. This is a direct link into the
Microsoft Public Newsgroups, and it is FREE and DOES NOT require a Usenet
account with your ISP. With OEx, you can easily find your post, track
threads, cross-post, and sort by date, poster's name, watched threads or
subject.

Not sure how? It's easy:
How to Configure OEx for Internet News
http://support.microsoft.com/?id=171164

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft MVP - Windows Server Directory Services
Microsoft Certified Trainer
Assimilation Imminent. Resistance is Futile.
Infinite Diversities in Infinite Combinations.
=================================
 
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