How can I make public DNS server?

I tried to make public DNS server with bind9, but I only can do requests from localhost. Read lots of articles, but still can’t do it. OS - Ubuntu 14.04, named.conf.options: options { directory “/var/cache/bind”; dnssec-validation no; listen-on { any; }; listen-on port 53 { any; }; allow-query { any; }; allow-recursion { any; }; allow-transfer { none; }; allow-query-cache { none; }; recursion yes;

    auth-nxdomain no;    # conform to RFC1035
    listen-on-v6 { any; };

};

root@p2p:/home/yngwie# netstat -tulpn | grep :53 tcp 0 0 public_ip:53 0.0.0.0:* LISTEN 29693/named tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 29693/named tcp6 0 0 :::53 :::* LISTEN 29693/named udp 0 0 public_ip:53 0.0.0.0:* 29693/named udp 0 0 127.0.0.1:53 0.0.0.0:* 29693/named udp6 0 0 :::53 :::* 29693/named