Quick question about Host records

[Bill Moseley]

At 03:08 PM 08/09/00 +0100, Jim Reid wrote:
>Suppose you list ns.hank.org as one of your name servers, but this has
>the same address as ns.jim.org, which is one of my servers. Maybe I'm
>your ISP or I offer a slave DNS facility for hank.org as a favour. One
>day I renumber ns.jim.org. When that happens the entry for ns.hank.org
>in the .org zone would still point at the old address which might not
>run a name server or even be in use any more. Now what if ns.jim.org
>provides slave DNS service for a lot of .org zones? Aside from the
>tedium of getting all those delegations updated, what if I forget to
>tell one of my customers or they fail to change their delegation
>information? Does this clarify things enough?

Yes, I see what you are saying.  But it seems like you are describing
problems that result from errors in administration, not so much problems in
the DNS system caused by two names assigned to the same IP.  I guess it
depends on what's changing: A name server for a bunch of domains gets moved
to a new IP, or one domain hosted on a name server serving lots of domains
gets assigned to a new name server.

I can see benefits from allowing multiple names for the same IP number:

Just like you can setup smtp1.example.com and smpt2.example.com to point to
the same mail server (and setup 1/2 the clients to use each).  Then, when
needed, split the load on that mail server by pointing smpt2 to a new IP
address and having to avoid changing all the client configurations.  The
same could be done with NS setup.

That is, say I'm a new ISP and I have only two machines each running a name
server ns1.example.com and ns2.example.com.

I want to host a bunch of domains.  With the current system, all the
domains (example1.com example2.com and example3...) must use
ns1.example.com and ns2.example.com.

Now, say the people at example3.com are getting very big and hogging
example.com's name servers.  So I buy two new machines to handle their DNS
needs and call them ns1 & ns2.example3.com.

I now have to not only change the registrar's record for example3 to
reflect the new name servers, but everyone in example.com that has their
resolver setup to use ns1 & ns2.example.com much now switch their settings
to ns1 & ns2.example3.com.

It would have been easier to just setup ns1 & n2.example3.com from the
start and tell everyone at example3.com to use ns1 and ns2.example3.com.
Then when I need to move their DNS I only change it at the registrar (and
in example3's zone).  The win is that you don't have to then go through all
of example3's client machines changing their DNS settings.

Anyway, it's a moot point:

Attempting to register a new host name for an existing registered IP via
Dotster returned this:

  540: Attribute value not unique

Attempting to register the new host via NSI Host form returned this:

  We are unable to process the Host Form below because
  of an error within the form. In particular, we noted:


  In order for Network Solutions to process this Host Form,
  you should correct this error and return this form to 
  hostmaster at networksolutions.com.

Now, that's a very helpful error message that they noted ;)


Bill Moseley
mailto:moseley at hank.org