Follow the Below Steps to Configure Slave Dns Server With Bind ( Secondary Dns Server ) In Linux:
Step: 1 Configure from Master Server End
Before configure the Slave/Secondary DNS Server we need to do some changes in our all Master/Primary DNS Server configuration files i.e. named.conf ( Main Configuration File ), itsmarttricks.com.for ( Forward Zone ), itsmarttricks.com.rev ( Reverse Zone ) to allow the Query and Zone record transfer to Slave Server.
First configure the /etc/named.conf
Let’s go ahead and configure the /etc/named.conf in Master Server. All changes are highlighted in Blue Color.
//
// 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 { 127.0.0.1; 192.168.1.100; };
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; 192.168.1.0/24; };
allow-transfer { 192.168.1.101; };
recursion yes;

      dnssec-enable yes;
      dnssec-validation yes;

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

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

};
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";
### itsmarttricks Internal Zones ###

  ### Forward Zone ###

  zone "itsmarttricks.com" IN {          # Domain Name
          type master;
          file "itsmarttricks.com.for";  # Name of the Forward Zone File
          allow-update { none; };
          allow-transfer { 192.168.1.101; };
  };

  ### Reverse Zone ###

  zone "1.168.192.in-addr.arpa" IN {  # IP Address
          type master;
          file "itsmarttricks.com.rev";  # Name of the Reverse Zone File
          allow-update { none; };
          allow-transfer { 192.168.1.101; };
  };

Read More - https://www.itsmarttricks.com/how-to-configure-slave-dns-server-with-bind-secondary-dns-server-in-linux/