Does bind has some dns-server ips inside?

zhjim · 11-07-2006, 11:25 AM

Hy folks,

I don't think the title is very clear but could not describe it with fewer words. So here comes my question:

When you don't state any DNS-Server in named.conf ( I'm doing it with forwarders {IP...} ) it just magicly uses some. don't know where it gets the IP from, but the querys are ok and everything. Also when I state my ISP DNS-Server through <b>forwarders ...</b> it uses the right DNS-Server.

Can anyone comfirm that. Everythings working fine. I just wonder where BIND gets these IP's.

To check on it use the simple chaching name-server-config from the manual.

Code:

// Two corporate subnets we wish to allow queries from.
acl corpnets { 192.168.4.0/24; 192.168.7.0/24; };
options {
directory "/etc/namedb"; // Working directory
allow-query { corpnets; };
};
// Provide a reverse mapping for the loopback address 127.0.0.1
zone "0.0.127.in-addr.arpa" {
type master;
file "localhost.rev";
notify no;
};

and make iptables show the outgoing dns querys.

Code:

iptables -I OUTPUT 1 -p udp --dport 53 -j LOG --log-prefix "DNS:"

For my case it does not use the dns-server in /etc/resolv.conf.

Would be nice if someone would check on this.

Regards Zhjim

acid_kewpie · 11-07-2006, 11:29 AM

BIND would use the root hints file to go to the main internet name servers, A to M.ROOT-SERVERS.NET. as these handful of DNS servers form the very ultimate point of name resolution for the net, it's not too naive to hardcode their ips.

http://www.linuxfromscratch.org/blfs...rver/bind.html check the root hints section.

zhjim · 11-07-2006, 12:05 PM

Sadly i could not find the root.hints file on my system (Debian). Nonetheless I have dig installed which was named to somehow also work with the root.hints file.

After all i was just wondering if this is "normal" behavior, so I can sleep sound.

Thanks for the quick answer