Delagation

Kevin Darcy kcd at daimlerchrysler.com
Thu Apr 13 21:32:29 UTC 2000


Barry Margolin wrote:

> In article <38F62A4B.8056087C at daimlerchrysler.com>,
> Kevin Darcy  <kcd at daimlerchrysler.com> wrote:
> >Barry Margolin wrote:
> >
> >> In article <38F61F82.DB8AA479 at daimlerchrysler.com>,
> >> Kevin Darcy  <kcd at daimlerchrysler.com> wrote:
> >> >I've often wondered why people prefer to delegate these "classlessly
> >> >delegated" PTR-containing zones from the in-addr.arpa tree at all. The zone is
> >> >just a container: it can be *anything* that's under the control of the entity
> >> >wishing to maintain the entries. By hanging the container zone off of
> >> >in-addr.arpa, you're basically doubling the workload of the provider
> >-- not only
> >> >do they have to generate ($GENERATE?) the CNAMEs, but they also have
> >to delegate
> >> >the container zone. This is an inequitable division of work, and I think it
> >> >underlies one of the reasons why many ISP's simply refuse to do "classless
> >> >delegation".
> >>
> >> Most of the work is in creating the CNAME records.  Delegating the reverse
> >> subdomain is a minor addition, and I don't think it has anything to do with
> >> why some ISPs don't do classless delegation.  I believe the main reason is
> >> that some of them simply aren't familiar with it.
> >
> >Agreed, that's almost certainly the main reason. But the workload I think
> >is another
> >reason. A lot of smaller ISP's probably only have 1 person who really
> >knows DNS very
> >well, and they're probably already busy enough setting up forward zones.
>
> I still don't understand what "workload" you're talking about?  How much
> more work is it to type:
>
> 32/27 IN NS ns1.customer.com.
> 32/27 IN NS ns2.customer.com.
>
> before typing the 32 CNAME records.  Even if they're using $GENERATE,
> typing 3 lines isn't much more work then typing 1.  The file is already
> open, so what's the problem?

Admittedly it doesn't add much. I was only speaking in incremental terms. It just
seems like more of a hassle when there's an extra step involved; one more thing to
get wrong, one more thing to verify if and when problems are reported, etc. It's just
simpler and cleaner in my view if the ISP only needs to generate the CNAMEs and leave
the delegation up to the customer. Then again, I've never worked at an ISP...


- Kevin





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