DNS Configuration

https://www.youtube.com/watch?v=ddRMrfxM3Eg
cat > /etc/named.conf

//
// 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.
//
// See the BIND Administrator’s Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.html

options {
listen-on port 53 { 127.0.0.1; 192.168.1.7;};
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”;
recursing-file “/var/named/data/named.recursing”;
secroots-file “/var/named/data/named.secroots”;
allow-query { localhost; any;};

    /*
     - If you are building an AUTHORITATIVE DNS server, do NOT enable recursion.
     - If you are building a RECURSIVE (caching) DNS server, you need to enable
       recursion.
     - If your recursive DNS server has a public IP address, you MUST enable access
       control to limit queries to your legitimate users. Failing to do so will
       cause your server to become part of large scale DNS amplification
       attacks. Implementing BCP38 within your network would greatly
       reduce such attack surface
    */
    recursion yes;

    dnssec-enable yes;
    dnssec-validation yes;

    /* Path to ISC DLV key */
    bindkeys-file "/etc/named.root.key";

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

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

};

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”;

zone “appsdba.info.” IN {
type master;
file “appsdba.info.zone”;
allow-update { none; };
};

zone “1.168.192.in-addr.arpa.” IN {
type master;
file “1.168.192.in-addr.arpa”;
allow-update { none; };
};

include “/etc/named.rfc1912.zones”;
include “/etc/named.root.key”;

cat > /var/named/appsdba.info.zone
$TTL 86400
@ IN SOA localhost root.localhost (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS localhost
localhost IN A 127.0.0.1
erpr12 IN A 192.168.1.5
racs-scan IN A 192.168.1.41
racs-scan IN A 192.168.1.42
racs-scan IN A 192.168.1.43
lb IN A 192.168.1.90
lb IN A 192.168.1.91

cat > /var/named/1.168.192.in-addr.arpa
$ORIGIN 1.168.192.in-addr.arpa.
$TTL 1H
@ IN SOA dns.appsdba.info. root.dns.appsdba.info. ( 2
3H
1H
1W
1H )
1.168.192.in-addr.arpa. IN NS dns.appsdba.info.
101 IN PTR erpr12.appsdba.info.
102 IN PTR racs-scan.appsdba.info.
103 IN PTR racs-scan.appsdba.info.
104 IN PTR racs-scan.appsdba.info.
105 IN PTR lb.appsdba.info.
106 IN PTR lb.appsdba.info.

systemctl restart named

systemctl status named.service

nslookup racs-scan.appsdba.info
nslookup lb
nslookup erpr12.appsdba.info

systemctl disable firewalld

firewall-cmd –zone=public –add-port=53/tcp –permanent
firewall-cmd –zone=public –add-port=53/udp –permanent
firewall-cmd –reload