newbie ques re bind & namevirtualhost

[Kevin Darcy]

Yes, one of the problems of having multiple names point to the same
address is that it creates a reverse-lookup ambiguity -- to which of
those names should the PTR point? Generally, though, if you're running a
server, it doesn't really matter if your reverse record points to only
*one* of the names by which you are known, since no application
AFAIK does a forward lookup, followed by a reverse lookup, and then
tries to match the two; generally it's a *server* that looks up a
*client's* IP address, i.e. the reverse lookup is first, then does a
forward lookup on the name to verify that it matches the address. And
that works fine with many-A's-but-only-one-PTR.

Another approach is to just pick one of the names to be the "true" name
and make the others aliases to it. Then the PTR just points back to the
"true" name. Be aware, though, that you can't use aliases on the
right-hand side of things like NS records, MX records, etc.. You'll have
to use the "true" name for that. This might affect your decision of
which name should be the "true" name, e.g. you might want the "myns"
name to be the A record. This is why it's common to see a whole bunch of
aliases in a zone pointing to the nameserver's A record.


- Kevin

tk dev wrote:

> dear all
>
> i apologise if my ques is too simple, but i just don't
> know what to do. pls help.
>
> i've read the first few chapters from "dns & bind"-3rd
> edition,oreilly.
>
> the samples given in the book showed the ns, hosts
> with different i.p.
> in my case, i've one machine & one ethernet card.i'm
> running suse6.4 with named8.2.2-P5 & ..bind8-8.2.2 (i
> got this from
> #named -v)
>
> my ques :
> 1.can i assign more than 1 i.p. on that ethernet card?
>
> 2.can my name server be in the same machine with the
> same ip as all my virtualhosts(web)?
>
> 3.since i used name-based virtual hosts, i'm confused
> as to how to configure the db files?
>
> let's say my ns is called myns.domain.com.(10.0.0.20)
> my virtualhosts to be:
>   - host1.domain.com \
>   - host2.domain.com -  all with the same i.p.
>   - h1.domain2.com   /  e.g. for test 10.0.0.20
>
> in db.domain.com
> can i have
> #name server
> @  IN NS myns.domain.com.
>
> #addr for canonical names
> localhost IN A 127.0.0.1
> myns      IN A 10.0.0.20
> host1     IN A 10.0.0.20
> host2     IN A 10.0.0.20
>
> -I'M a very confused here if different names point to
> 1 ip, i.e. 1 addr will also points to different names
> in the PTR record, then all will be jumbled
> up!!(inclusive of the fact that h1.domain2.com. will
> also points to 10.0.0.20)
>
> Pls help! i'm really at a standstill right now.
>
> thanks in advance for all your help.
> bye
> tk
>
> =====
> 0Oo~~:o)
> Smile! You'r Alive!!!
>
> Q:What's peacefulness?
> A:What's confusion? Peacefulness is the end of confusion.
>
> o.0.Oo.o May there be peace in every step we take :o):tk
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Mail - Free email you can access from anywhere!
> http://mail.yahoo.com/