internal DNS

Winanjaya · 01-31-2010, 11:47 PM

Dear All,

I want to have an internal DNS that would serves our LAN .
and I also had external DNS server..(located on our ISP)
I have configured my internal DNS .. by adding new A record named test.mydomain.com (for example) and I knew that test.mydomain.com also exists as A record on external DNS server..

when I ping test.mydomain.com .. it still return from 202.x.x.x (it should be return from 172.16.250.1? ..

it seems like my internal DNS config below not configured properly..
what I missed? please help

thanks & regards
Winanjaya

//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//

options {
listen-on port 53 { 172.16.250.2; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { localhost; 172.16.250.0/24; };
recursion yes;
forwarders {
202.a.b.c;
61.a.b.c;
};
};

logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};

include "/etc/named.rfc1912.zones";

server 202.a.b.c {
};
server 61.a.b.c {
};
zone "mydomain.com" {
type master;
file "/var/named/mydomain.com.hosts";
};
zone "250.16.172.in-addr.arpa" {
type master;
file "/var/named/172.16.250.rev";
};

and in /var/named/mydomain.com.hosts

$ttl 38400
mydomain.com. IN SOA public. it-department.mydomain.com. (
1265027872
10800
3600
604800
38400 )
mydomain.com. IN NS public.

test.mydomain.com. IN A 172.16.250.1

bathory · 02-01-2010, 12:38 AM

Hi,

I guess you're using your internal dns IP in /etc/resolv.conf.
Now this configuration is not going to work, because you have

Quote:

mydomain.com. IN NS public.

that I guess is the dns at your isp. You should change it to the internal dns and add an A record for it:

Code:

mydomain.com. IN NS internal-dns.domain.com.
internal-dns.domain.com.IN A 172.16.250.1
test.mydomain.com. IN A 172.16.250.1

Regarding named.conf, there are also some things not needed:

Quote:

forwarders {
202.a.b.c;
61.a.b.c;
};

Useless without a forward statement. Besides you don't need to forward queries at public dns if you want to use the internal one (*).

Quote:

server 202.a.b.c {
};
server 61.a.b.c {
};

Also useless as there are no additional options for these servers.

(*)Maybe you should consider using a split dns setup, with the internal view user by your LAN clients and the external to forward queries at the public dns.

Regards