dns question

[Jason Opperisano]

On Thu, 2004-11-18 at 07:32, Peter Marshall wrote:
> I am sure this is a stupid question ...but I will ask anyway.  Should I be
> allowing my dns server (in my dmz) connect to root servers ?   At the moment
> it is being bloced, and the only thing it can connect to is my ISP's DNS
> server.  Basically, my dns server serves requests for servers in my dmz for
> my internal users.  If it can't find the hit, it passs the request on to my
> ISP's ... I am trying to clean up my firewall logs, and noticed that the DNS
> server is always trying to query root servers.  I was just not sure if this
> should be allowed.  If it is not, (and I suspect there is no need to) Is
> there a way to make my DNS server stop quering the root servers ?
> 
> PS  DNS is a rh9 box running bind.

oops...apparently CTRL+ENTER sends a message in evolution before you're
done typing--sorry about that last message...

if you're specifying:

        forwarders {
                x.x.x.x;
                x.x.x.x;
        };
        forward only;

then your DNS server should not be falling back to the root servers if
your ISP's servers don't have the answer.  the drawback is--if your
ISP's servers don't have the answer--your clients will get a negative
response, which usually isn't what you want.

i normally specify:

        forwarders {
                x.x.x.x;
                x.x.x.x;
        };
        forward first;

and in that case--you need to allow the DNS server out to any IP on port
53, not just to the root servers (the root servers do not provide
recursion).

-j

--
"Dear Baby, Welcome to Dumpsville. Population: You"
	--The Simpsons