Re: zone before delegation?

2011-10-29 Thread Bill Owens
On Fri, Oct 28, 2011 at 05:39:05PM +, Laws, Peter C. wrote:
 OK, so simply putting the NS records in the parent zone is sufficient to make 
 it a separate zone.  No need to put stuff in named.conf unless I want to or 
 until I actually delegate to a different set of nameservers.

Actually, the opposite - sorry if I was unclear. Maybe an example will help. . .

If we start with this config:

zone example.com {
type master;
file /usr/local/etc/bind/example.com.zone;
};

# example.com.zone
$TTL 86400
@   IN  SOA ns.example.com  hostmaster.example.com (
2011102900 86400 14400 864000 86400 )
IN  NS  ns.example.com.
;
www IN  A   192.0.2.1

We can add a subdomain of example.com simply by creating the zone file and 
adding an entry in named.conf, *without* placing anything in the example.com 
zone itself:

zone test.example.com {
type master;
file /usr/local/etc/bind/test.example.com.zome;
};


# test.example.com.zone
$TTL 86400
@   IN  SOA ns.example.com  hostmaster.example.com (
2011102900 86400 14400 864000 86400 )
IN  NS  ns.example.com.
;
testserver  IN  A   198.51.100.20

There is no connection between example.com and test.example.com, since the 
records for test are in a separate zone and there's no delegation point (no NS 
records for 'test.example.com'). However, any queries for test.example.com have 
to work through example.com first, and the same server knows about both zones. 
When someone asks for 'testserver.test.example.com' at ns.example.com, it will 
provide an authoritative answer for the A record and include an NS record in 
the additional section. Everything will work just fine; that's true even if 
there are additional authoritative servers, as long as all of the servers for 
example.com are also authoritative for test.example.com.

That said, here's the right way to do it; after creating the subdomain zone 
file and adding the entry in named.conf, go back to the parent:

# example.com.zone
$TTL 86400
@   IN  SOA ns.example.com  hostmaster.example.com (
2011102901 86400 14400 864000 86400 )
IN  NS  ns.example.com.
;
www IN  A   192.0.2.1
;
testIN  NS  ns.example.com.

Now everything's consistent and complete. That configuration will always work, 
regardless of the location of the authoritative nameserver(s) for 
test.example.com. It will also work when you sign test.example.com and add DS 
records in example.com to secure it.

 My thought was to create the new zones as zones on the parent server as a 
 prelude to actually delegating them, in a  sense, delegating the zone to 
 myself.  That will let me clean stuff up and get it ready for the coming 
 move.  

That's fine, but still create the NS records. You can keep them at a low TTL 
until your transition, if you want to speed up the process when you do make the 
change.

 Yes, DNSSEC is, IMHO, much like IPv6 - no one wants to mess with it but a lot 
 of people claim it's inevitable.  *Hopefully* both will end up like maglevs 
 and monorails - technology of the future: always has been, always will be.  
 :-)

Actually I think they're very different. Both will require some effort and some 
pain; IPv6 more of both and for less obvious return (though it truly does have 
some significant advantages). DNSSEC - once it is sufficiently deployed - will 
make some very cool things possible, well beyond the basic, but very important 
addition of end-to-end DNS integrity. Have a look at the freshly minted RFC 
6394 for one early example. . .

Bill.
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RE: zone before delegation?

2011-10-29 Thread Scott Morizot
On 28 Oct 2011 at 17:39, Laws, Peter C. wrote:
 OK, so simply putting the NS records in the parent zone is
 sufficient to make it a separate zone.  No need to put stuff in
 named.conf unless I want to or until I actually delegate to a
 different set of nameservers. 

If you put NS records delegating a subdomain in the parent zone file, 
that creates a zone cut and you can no longer have any records in the 
parent about the child zone except glue records (if one or more of the 
nameservers for the child zone lie below the zone cut) and DS records 
(which are owned and signed by the parent zone and are the one record 
type that don't follow the zone cut rule).

 My thought was to create the new zones as zones on the parent server
 as a prelude to actually delegating them, in a  sense, delegating
 the zone to myself.  That will let me clean stuff up and get it
 ready for the coming move.  

Not sure I understand what you're trying to do, but this is the most 
correct order for establishing a new delegated zone (or moving a zone 
from one nameserver to another). First configure the zone as a master 
zone on the nameservers on which it will run. (Create the zone files and 
the configuration in named.conf on the new nameservers for the zone, 
whether or not they are the same nameservers as the parent.) Make sure 
those nameservers can respond authoritatively for the zone. Then add or 
change the NS records in the parent zone.

The first step configures the nameservers so they can respond 
authoritatively for the zone. The second step tells the rest of the world 
to query those nameservers for the zone. If you're creating a new zone 
cut and you're putting the new child zones on the same nameservers as the 
parent zone, then you can do both steps at once. On the master 
nameserver, move all the child records to the new zonefiles, add the NS 
records to the parent zone, change the named.conf configuration and 
restart named. And update the named.conf with the new child slave 
configuration on the other nameservers.

 Yes, DNSSEC is, IMHO, much like IPv6 - no one wants to mess with it
 but a lot of people claim it's inevitable.  *Hopefully* both will
 end up like maglevs and monorails - technology of the future:
 always has been, always will be.  :-) 

Hopefully? So you actually want people to be able to spoof your 
authoritative DNS records almost at will? That's a curious perspective.

And while IPv6 transition is, at this point, not certain, what is certain 
is that we're effectively out of IPv4 addresses. APNIC has been out for a 
while. RIPE runs out in the next few months. It's uncertain at this point 
when ARIN will run out, but ARIN, AfriNIC and LACNIC will all run out 
sometime in the next couple of years. The only alternative to IPv6 is to 
return to a world of separate proprietary enclaves rather than a single, 
global inter-connected set of networks running the same protocol. It's a 
world of rationing where everyone can only run and access what their 
provider allows and supports. It's an ugly world and nothing at all like 
the Internet we've enjoyed for the past couple of decades. I'm old enough 
to remember what things were like when networks were all proprietary 
enclaves and I'm not eager to return to that model personally. It's 
doubtful that all the CGN solutions will really be the same and likely 
only certain protocols/ports will be supported -- throttling the 
development of new technologies. And it creates a scarcity model which 
will likely push prices for using the service up. With that world as the 
only likely alternative, I certainly hope IPv6 transition succeeds.

Scott

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