You can change a default DNS Zone template which is used when creating a new-account or domain.
By default, cwp is using default.tpl for all new accounts and domains.

If you need to change it please note that you need to make a file as default.tpl is overwritten on every cwp update.
Default DNS Zone template files are in this folder: /usr/local/cwpsrv/htdocs/resources/conf/dns/bind/zones/

When you create a new file then you can activate it as a default from cwp.admin -> CWP Settings -> Edit Settings

Options that are replaced:

%domain% = new domain
%dns-email% = email of domain owner
%ns1% = nameserver 1
%ns2% = nameserver 2
%ip% = account/domain IP address

Please read more detailed info here.

Create configuration file: /root/dns_sync_slave2.conf

USERNAME="slave"
SERVER="121.122.123.124"
SSHPORT="22"
SOURCESYNCLOCATION="/var/named/slave"
CHECKMAINDNS="centos-webpanel.com"
LOCALSYNCLOCATION="/var/named/slave"
LOCALCONFFILE="/etc/named/slave_additional.conf"

* SERVER = IP of Slave DNS Server & Manager.
* SSHPORT = SSH-Port of Slave DNS Server & Manager.
* SOURCESYNCLOCATION = Location of DNS zone files on Slave DNS Server & Manager.
* CHECKMAINDNS = This is a domain used for testing Slave DNS Server & Manager, it can be any and it doesn't need to be on the server.
* LOCALSYNCLOCATION = Location for DNS zone files on this local server.
* LOCALCONFFILE = Configuration files which contains the list of all zone files on this local server.

Setup cron how often you want to check for changes

crontab -e

* On servers with many clients and domains 100+ we recommend 5min cron.
* For servers with 1000+ you can go even with every 1-2 minutes.
example every 1 minute

* * * * * sh /scripts/dns_sync_slave2

In file /etc/named.conf after last include add:

include "/etc/named/slave_additional.conf";

Prepare config files

touch /etc/named/slave_additional.conf
chown named.named /etc/named/slave_additional.conf

go in cwp.admin -> Server Settings -> SSH Key Generator
there you need to generate new Keys

Go to Slave DNS Server & Manager
add key to the Slave DNS Server & Manager user you are using as "slave"

mkdir /home/slave/.ssh
nano /home/slave/.ssh/authorized_keys

** paste your key here which you had generated on the Slave2 DNS Server

chown -R slave.slave /home/slave/.ssh
chmod 600 /home/slave/.ssh/authorized_keys
chmod 700 /home/slave/.ssh/

You will also need to enable bash shell for that user so rsync could work

chsh -s /bin/bash slave

You can now test ssh connection like this from Slave2 DNS Server to Slave DNS Server & Manager
ssh slave@SERVER-IP -p SSH-PORT
If your connection goes ok without asking for the password then you are fully set.

Latest Update: March 7, 2021

For Slave DNS Manager is recommended that you have a clean server with CWP which will be used as Slave DNS (ns2).

Create a New Account on the CWPpro Server
* This is the server you plan to use as Slave DNS Server & Manager
username: recommended is slave (as it will be used in the tutorial)
domain: domain which you plan to use for slave dns manager gui and API access

Download Slave DNS Manage and upload it to public_html folder on your cwp account
Latest update: July 20, 2019. (manual update required by overwriting files)

cd /home/USERNAME/public_html
wget http://dl1.centos-webpanel.com/files/cwp/addons/cwp-slave_dns.zip
unzip cwp-slave_dns.zip
mv slave_dns/* .
rm -f index.html

Fix file permissions (you can do that also from cwp)

chown -R USERNAME.USERNAME /home/USERNAME/public_html/*

MySQL: Create User and Database
Go to CWP module: MySQL Manager --> Create Database and User

Edit file /home/USERNAME/public_html/inc/db_conn.php.sample and enter your database connection details
Rename sample file to get DB connection into production

mv inc/db_conn.php.sample inc/db_conn.php

Import database by using PhpMyAdmin or with MySQL command

mysql DATABASENAME < sql/slave_dns.sql

Create permissions for the user to be able to control the bind DNS.
Replace USERNAME with the user of the account you had created in cwp

FILENAME: /etc/sudoers.d/USERNAME

%USERNAME  ALL= NOPASSWD: /bin/systemctl start named
%USERNAME  ALL= NOPASSWD: /bin/systemctl stop named
%USERNAME  ALL= NOPASSWD: /bin/systemctl restart named
%USERNAME  ALL= NOPASSWD: /bin/systemctl reload named
%USERNAME  ALL= NOPASSWD: /bin/systemctl status named
%USERNAME  ALL= NOPASSWD: /bin/systemctl is-active named

touch /etc/named/slave.conf
chmod 771 /etc/named
usermod -a -G named USERNAME
chown USERNAME.named /etc/named/slave.conf

mkdir /var/named/slave
chown named.named /var/named/slave

Edit File: /etc/named.conf and add this in options section before closing }

masterfile-format text;

Add after options{} where other include lines are specifed

//Slave dns configuration
include "/etc/named/slave.conf";

Now you can login to DNS Manager GUI by using a domain link of the account you have created

Default login for DNS Manager GUI admin/root
Username: root
Password: FX8QKxvQ
* Please change the default password after the first login

Adding WebServers to DNS
- On dns manager GUI create a new user for each server or use a single for all webservers if you plan to transfer accounts from one to another webserver.
- On CWP WebServer go to DNS Functions -> Slave DNS Manager

For Slave Host you need to use the same URL you are accessing DNS Manager GUI, example

http://slave-dns.manager.domain.com

* You can also add this as an addon domain to the account later.

CWPpro WebServer configuration

Edit File: /etc/named.conf and add this in options section before closing }

//Slave dns configuration
allow-transfer {111.112.113.114;};
allow-recursion {111.112.113.114;};
also-notify {111.112.113.114;};
masterfile-format text;

Mostly know issues
issue: domain/zone not deleted from /etc/named/slave.conf
apache logs file: /usr/local/apache/domlogs/DOMAIN.error.log
apache logs line: sed: couldn't open temporary file /etc/named/sedzizIXw: Permission denied
solution: chmod 771 /etc/named

issue: Slave BIND/DNS not showing changes
solution: try to restart named and check if the service has some errors in the /var/log/messages

Please note that we have two options of slave DNS:
- Slave DNS Server on our hosted server (you get an account with domain limit you need)
- Slave DNS Server download version (a full and FREE Slave DNS Manager where you can add/remove users, set domain limits and manage domains)
* The only requirement is to have a CWPpro license.

Slave DNS Server & Manager on our hosted server
For those having only a single VPS or dedicated server and with a need additional remote DNS server as ns2 they can order a slave DNS from our website.

Features of CWP Slave DNS server hosted by us:
- Automatic sync DNS zones from a master server (your CWPpro) on serial change.
- Automatic sync DNS zones on add/remove.
- Manage DNS zones/domains from your CWP or our Website GUI.
- You get an account on our Slave DNS Manager where you have a limited number of domains based on the package you order.
- You don't need to buy an additional server and manually setup DNS on it.

You can order it here.

Slave DNS Server & Manager download version
A Full and FREE Slave DNS Server & Manager where you can add/remove users, set domain limits and manage domains.
The most important part is that this is a completely FREE and scalable for bigger hosting providers with many domains.

Features of CWP Slave DNS Server & Manager download version:
- Completely FREE, The only requirement is to have CWPpro to be able to sync zones.
- Automatic sync DNS zones from a master server (your CWPpro) on serial change.
- Automatic sync DNS zones on add/remove.
- Unlimited number of accounts.
- Option to limit the number of domains per account (if you sell/offer DNS cluster to other clients).
- Ability to connect multiple Slave2 DNS Servers (used as DNS Cluster).
- Ability to connect multiple CWPpro WebServers on a single account.
- Ability to connect multiple CWPpro WebServers on separate accounts.

You can check the installation instructions here.

Possible scenarios:
You can connect multiple CWPpro WebServers to single Slave DNS Manager and make it as ns2 for all of the CWPpro Webservers.
You can also use it as ns1 and then add multiple additional Slave2 DNS Servers as ns2, ns3, ns4....

Slave DNS Server & Manager - How it works:
In CWPpro WebServer on dns zone serial change, new account/domain/subdomain add/remove/edit it syncs DNS zone to the Slave DNS Manager.
DNS Zone is added to Slave DNS Manager from CWPpro WebServer via API on the Slave DNS Manager then Bind dns server (on the slave) transfers zone to itself acting as a slave dns server.

Slave2 DNS Server - How it works:
Big providers mostly have a custom DNS Cluster which handles all dns domains they have on multiple webservers to reduce resource usage by dns on the webservers.
Slave2 DNS Server is designed to be an additional DNS Server for big providers which need to have stability if some DNS servers get overloaded or unavailable.

It's using rsync running via cron which checks for changes on the Slave DNS Manager and based on the changes from rsync it will add or remove dns zone from itself.
It also has the ability to check if Slave DNS Manage is responding on dns queries before accepting new changes to prevent multiple DNS servers to be down at the same time.

Slave DNS Servers can be located in different data centers worldwide.

You can check the installation instructions for Slave2 DNS Servere here.

INFO
* Only WebServers need to have CWPpro, DNS servers don't need to have it.

You can register and start using FreeDNS here
http://freedns.centos-webpanel.com

To start using FreeDNS you need to set following Name-Servers for your domain with your domain registrar:

ns1.centos-webpanel.com
ns2.centos-webpanel.com

Starting named:
Error in named configuration:
/etc/named.conf:57: zone 'ns1.web.co.uk': already exists previous definition: /etc/named.conf:46
/etc/named.conf:58: zone 'ns2.web.co.uk': already exists previous definition: /etc/named.conf:47
[FAILED]

Edit file /etc/named.conf with your favorite file editor or from CWP and remove duplicated entries for above specified zones.

It's required that you have installed CentOS WebPanel and at least one public IP address.
** Please note that some domain providers will require that you have IP from two different IP ranges.

Settings
CWP.admin - DNS Functions --> Edit NameServers IPs

Add here add your subdomains you want to use for the NameServers and one IP for each nameserver eg.
ns1.centos-webpanel.com --> 185.4.149.83
ns2.centos-webpanel.com --> 185.4.149.90

If you are using one IP then it should looks like:
ns1.demo.com --> 185.4.149.83
ns2.demo.com --> 185.4.149.83

Don't forget that this NameServer must be registered with your domain registrar or they will not work!!!

Changing DNS records can take up to 24-48 hours!!!

Please use this website for quicker/live DNS testing: http://leafdns.com/

Enom Instructions: http://www.enom.com/help/faq_dns.asp
Godaddy Instructions: https://uk.godaddy.com/help/add-my-own-host-names-as-nameservers-12320
NameCheap: https://www.namecheap.com/support/knowledgebase/article.aspx/768/10/how-do-i-register-personal-nameservers-for-my-domain