dns server in ubuntu

I need a simple DNS server to work around my experiment. Here is my steps to build a dns server in ubuntu.

1. apt-get install bind9

2. update /etc/bind/named.conf.options
        forwarders {
                8.8.8.8;
        };

        dnssec-enable no;
        //dnssec-validation auto;

       // listen-on-v6 { any; };

3. /etc/init.d/bind9 restart

When encounter the error like,
named[4597]: error (network unreachable) resolving './NS/IN': 2001:dc3::35#53
It seems like the ipv6 address cannot be reachable, so just disable ipv6 setting.

named[4597]: error (no valid RRSIG) resolving 'gov/DS/IN': 192.203.230.10#53
disable dnssec to workaround this error.

Reference:
http://ubuntuforums.org/showthread.php?t=1984950