Secondary DNS

[Kevin Darcy]

Scott.McEwan at eu.nabgroup.com wrote:

> Hello,
> I am going to be setting up a secondary DNS from our primary,
> Can someone help as to where I need to make the addition with our Current DNS
> setup,
> for example i beleive  i need an addition to the named.conf and also on all
> zones.
>
> Any info would be greatly appreciated.

"Slave" is better terminology than "secondary".

Note that there are two different classes of slaves: "published" slaves versus
"stealth" slaves. Published slaves are known *globally*, so any caching-only
nameserver with the proper "hints" file, assuming the delegations are all correct,
can find a published slave and send it queries about the zone in question.
"Stealth" slaves, on the other hand, do not appear in the NS records for the zone,
so they are only known *locally*: the only clients or caching-only nameserver
instances which know to ask that slave about the zone are ones which are explicitly
configured to do so. The value of stealth slaves is that they enhance query
redundancy, performance and load balancing, without cluttering up the DNS namespace
with unnecessary NS records.

You didn't say _why_ you were setting up a slave, so it's hard to know whether it
would be better for you to go with a published slave or a stealth slave. If you're
just now growing your internal network to its second nameserver, I'd probably go
with a published slave, which will position you well if you want to add
caching-only nameserver instances later.

If you decide to go the "published slave" route, then remember to add a relevant
NS record to the delegation of the child zone from the parent zone, as well as to
the zone itself. Those sets of NS records should always match, except potentially
when you are migrating a zone from one set of nameservers to another. Note that if
the domain in question is a registered Internet domain, you'll have to go through
your registrar in order to change the delegation records for it.


- Kevin