Reverse mapping DNS update

[Kevin Darcy]

Well, the "bible" for DNS and BIND is titled, strangely enough,
_DNS_and_BIND_ (from O'Reilly). The latest edition is Third Edition,
which has been out a while, with Fourth Edition being worked on. Third
Edition only has a couple of pages specifically on "nsupdate". But
I think you probably need a more general overview anyway. Just running
nsupdate is one thing; understanding the whole milieu in which nsupdate
operates, is another.

As for websites, follow the links from the ISC website,
http://www.isc.org, especially http://www.dns.net/dnsrd.


- Kevin


Sivakumar Thiyagarajan wrote:

> >
> >No offense, but I think you need to do some more
> reading on how DNS
> >works.
>
> None taken and you bet I need hell a lot more reading
> to do. Thanks for your response.
>
> But was I way off in expecting the reverse mapping
> update to automatically take place, given that I was
> able to do the hostname-address mapping update.
>
> I am looking ito the RFC and also some books to
> decipher them. Can you point me towards any nice
> websites/books on nsupdate stuff? -  the general
> DNS stuff does not seem to discuss this.
>
> thanks
> p.s.
> sorry to use your personal(?) id. I lost my thread's
> header when I switched to the digest mode of the mail
> list.
>
> >Reverse (address-to-name) mappings in DNS are stored
> in a completely
> >different part of the namespace hierarchy than
> forward
> >(name-to-address)
> >mappings. If you want <ipaddress> to reverse-resolve
> to <hostname>,
> >this requires a totally separate and distinct record
> than the one which
> enables
> ><hostname> to forward-resolve to <ipaddress>.
> Specifically, for address
> >a.b.c.d, you'd need to add a record of type PTR with
> the name
> >d.c.b.a.in-addr.arpa. If you are not authoritative
> for the appropriate
> >reverse domain (e.g. c.b.a.in-addr.arpa,
> b.a.in-addr.arpa or
> >a.in-addr.arpa)
> >then in general you cannot create an address-to-name
> mapping for your
> >host.
> >Note, however, that if you have a smaller-than-256
> range of addresses
> >(let's
> >say, the lower half of a.b.c.*), then with the
> co-operation of the
> >owner of
> >the parent reverse domain (e.g. the owner of
> c.b.a.in-addr.arpa), you can
> >play some aliasing or delegation tricks to allow you
> effectively
> >control
> >those reverse mappings. See RFC 2317 for more details
> and/or search the
> >archives of this list for some permutation of
> "classless in-addr.arpa
> >delegation".
> >- Kevin
> >
> >Sivakumar Thiyagarajan wrote:
> >
> >> hi gurus,
> >>
> >> After using nsupdate to add a host and its ip
> address, given the hostname
> >> nslookup is able to get ip address when but not the
> other way around.
> >> i.e. given the ip address, the nslookup doesnt give
> the host name back.
> >>
> >> #  nsupdate
> >> > update add <hostname> <ttl> IN A < ipaddress >
> >> >
> >> Any thing else needs to be done? The host name
> appears in a DNS database
> >> dump though.
> >>
>
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