Re: DNS Reverse lookup zone

In article <bio593$193u$1@sf1.isc.org>,
Andrew Lee <gladius@gladius.f9.co.uk> wrote:
>Barry Margolin <barry.margolin@level3.com> a écrit:
>
>[snip]
>
>>>and then the zone file with
>>>$TTL 1D
>>>@ IN SOA ns1.example.com. hostmaster.example.com. (
>>>all the good stuff );
>>>NS ns1.example.com.
>>>1 PTR mail.example.com.
>>>2 PTR mail1.example.com.
>>>
>>>or would I need the PTR records to point to my ISP?
>>
>> The PTR records should point to your hostnames -- they should just be
>> the opposite of the A records that they're maintaining. So if they
>> have:
>>
>> mail.example.com. IN A x.x.x.1
>> mail1.example.com. IN A x.x.x.2
>>
>> then your records are correct.
>
>great. Would they then have to add A records for my nameserver?
>I.e. how does the rest of the world find my records - this is what

Yes, if the ISP is hosting example.com, and the reverse domain is delegated
to ns1.example.com, they have to create an A record for it.

>confuses me, if the ISP points an A record at my nameserver, then what
>happens when people try to resolve stuff that isn't on my name server?
>Do I need to add a forwarder in the options bit?

The only domains that anyone (other than your local users) should be
querying your nameserver for are the ones that are specifically delegated
to you.

If you have local users querying your nameserver as a resolver, it uses the
"hints" zone to find the root servers, and they tell your server how to
resolve names in outside zones. You don't normally need to use forwarders.

>As you can probably tell, I'm very new to this and am struggling to get
>my head around it properly.

Have you got the book "DNS & BIND"?

>
>>>and then would I not have any other zone files in there at all?
>>
>> There's usually a boilerplate zone for the 127.in-addr.arpa reverse
>> domain.
>
>Sorry, I'm not sure what you mean by this - I have a 127.0.0.zone zone file
>with this in.
.....
>Is this what you meant?

Yes. It's irrelevant to the issue of reverse DNS for your class C, I was
just mentioning it for completeness.

--
Barry Margolin, barry.margolin@level3.com
Level(3), Woburn, MA
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