what do i tell my isp?

[Kevin Darcy]

When you register a domain and the name of one or more nameservers for that
domain is *in* the domain itself (e.g. ns.mydomain.com is a nameserver for
mydomain.com), then you supply both the name of the nameserver and its
IP address, so that a so-called "glue record" can be created in the parent
zone (e.g. .com) to avoid the chicken-and-egg problem of not being able to
resolve names in the domain, including the name of the nameserver to use for
resolving names in the domain. The downside of "glue records", however, is
that if you ever change the address of that server, you have to not only
change it in your zone, but also tell your registrar to change the glue
record in the parent zone, otherwise the servers for the parent zone may
continue to give out stale information about that name.

"Classless delegation" is a technique for allowing one organization (e.g.
your ISP) to "delegate" the maintenance of certain names within a zone they
control, to some other organization (e.g. you), using aliases. It's typically
employed in cases like yours where the delegating organization has ownership
of a /24 reverse domain, e.g. 3.2.1.in-addr.arpa, and wants to allow other
organizations to be able to maintain different parts of that namespace (like
your 8-address range). If you and your ISP follow RFC 2317 strictly, then the
"classless delegation" process incorporates a "real" DNS delegation, namely,
from their /24 reverse zone to a subzone served by your nameservers. This
delegation, like any real delegation, requires you to provide the name of
your nameserver to the owner of the parent domain. But such a delegation
would rarely if ever require glue records, because no-one AFAIK puts the
names of their nameservers in the in-addr.arpa hierarchy. So, they probably
wouldn't need the IP address of your nameserver in that case, except possibly
as some sort of doublecheck against typos, etc.

Note that if you and your ISP don't follow RFC 2317 strictly, the aliases can
be pointed to reverse records contained in *any* zone that you control, even
a "forward" zone. In that case, your ISP wouldn't need to know the name of
your nameserver *or* its IP address. They would just need to know where you
want them to point the aliases.


- Kevin

mischa wrote:

> I leased a block of 8 ip's from my isp and want to set up my own dns for
> them. my registrar (dotster) requires a dns with a domain and not an ip,
>
> so for example, if mydomain.com is being delegated by ns.mydomain.com, how
> does my registrar know where ns.mydomain.com is?
>
> If im using classeless delegation, do i still need to provide one domain /
> ip combo for them to put in their dns?