Configure for External Network

[root@dlp ~]# yum -y install bind bind-utils

[root@dlp ~]# vi /etc/named.conf
.....
.....
options {
 # change ( listen all )
 listen-on port 53 { any; };
 # change if need ( if not listen IPv6, set [none] )
 listen-on-v6 { any; };
 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";
 secroots-file "/var/named/data/named.secroots";
 recursing-file "/var/named/data/named.recursing";
 # change : receive queries from all hosts
 allow-query { any; };
 # network range you allow to transfer zone files to clients
 # add secondary DNS servers if it exist
 allow-transfer { localhost; };

 .....
 .....

 # change : not allow recursive queries
 # answer to zones only this server has their entries
 recursion no;

 dnssec-enable yes;
 dnssec-validation yes;

 managed-keys-directory "/var/named/dynamic";

 pid-file "/run/named/named.pid";
 session-keyfile "/run/named/session.key";

 /* https://fedoraproject.org/wiki/Changes/CryptoPolicy */
 include "/etc/crypto-policies/back-ends/bind.config";
};

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

zone "." IN {
 type hint;
 file "named.ca";
};

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

# add zones for your network and domain name
zone "srv.world" IN {
 type master;
 file "srv.world.wan";
 allow-update { none; };
};
zone "0.16.172.in-addr.arpa" IN {
 type master;
 file "0.16.172.db";
 allow-update { none; };
};
# if you don't use IPv6 and also suppress logs for IPv6 related, possible to change
# set BIND to use only IPv4
[root@dlp ~]# vi /etc/sysconfig/named
# add to the end OPTIONS="-4"