As I understand it a DNS forwarder is an entry that forwards DNS queries to a
another DNS server

Recursive - means that if a DNS server can't resolve the host name
requested it will forward it to another DNS server

Er... isn't this the same thing?

Ciao

Paolo

"goundhog" <goundhog@discussions.microsoft.com> wrote in message
news:ADBAAB2F-0065-465D-8E87-176D452327A3@microsoft.com...
> As I understand it a DNS forwarder is an entry that forwards DNS queries
> to a
> another DNS server

Yes, that is the effect. The server to which the local server forwards is
referred to as "the Forwarder" (Odd thing is that the forwarder doesn't
even know it is a forwarder.)

> Recursive - means that if a DNS server can't resolve the host name
> requested it will forward it to another DNS server

No. Not exactly. Recursion is the act of working from the root (or
parent) down, asking another DNS server but using whatever information
it does know to find a child deeper in the tree until a server which is
authoritative is located.

> Er... isn't this the same thing?

No, but it can be confusing -- even to experts who think they understand
the terminology.

Recursion and Forwarding are contrasting terms.

But Iterative and Recursive are other contrasting terms. An iterative
query is one where a DNS reqestor (usually another DNS Server)
asks a simple question and does NOT expect the DNS server being
asks to "go find" the answer -- merely to answer what it knows
directly.

Recursive queries are when a DNS requestor turns over responsibility
to the DNS server being asked. This is normally the case for most
client queries and when a DNS Server forwards to another DNS
Server (i.e., the Forwarder.)

Weird thing is that Recursive queries are sent to forwwarders and
iterative queries are send when the local server is doing it's own
physical recursion.

--
Herb Martin, MCSE, MVP
http://www.LearnQuick.Com
(phone on web site)