Update 'Bind9 DNS Server'

Bind9-DNS-Server.md

@@ -128,3 +128,22 @@ linuxtechi@bind-server:~$
 ### Validating Syntax of bind9 configuration and Zone files
 If you want to cross verify the syntax of your bind 9 configuration file (named.conf.local). Use the command “named-checkconf“, example is shown below:
 ```
+linuxtechi@bind-server:~$ sudo named-checkconf /etc/bind/named.conf.local
+linuxtechi@bind-server:~$
+```
+If there is no syntax error in your bind configuration file, then it should return to shell without showing any errors.
+
+To cross verify the syntax your forward and reverse lookup zone files , use the command “named-checkzone“, example is shown below:
+
+```
+linuxtechi@bind-server:~$ sudo named-checkzone linuxtechi.local /etc/bind/forward.linuxtechi.local
+zone linuxtechi.local/IN: loaded serial 6
+OK
+linuxtechi@bind-server:~$
+linuxtechi@bind-server:~$ sudo named-checkzone linuxtechi.local /etc/bind/reverse.linuxtechi.local
+zone linuxtechi.local/IN: loaded serial 21
+OK
+linuxtechi@bind-server:~$
+```
+
+[Source](https://www.linuxtechi.com/install-configure-bind-9-dns-server-ubuntu-debian/)