Naming the IPv4 reverse DNS zone
To properly format the Domain field in the interface using IPv4:
1. Drop the last octet from the IP address.
2. Reverse the order of the remaining octets.
3. Append in-addr.arpa to the end of the remaining octets.
4. Enter this value in the Domain field of the Add a DNS Zone feature.
For example, the reverse DNS zone for 192.168.0.1 is 0.168.192.in-addr.arpa.
You will specify the last octet of the IP address within the zone file.
Installing cPanel DNS ONLY
To begin your installation, use the following commands:
Open the /home directory by typing the command cd /home
Fetch the latest installation file from the cPanel servers by typing the command
wget -N http://httpupdate.cpanel.net/latest-dnsonly
Open and run the installation files by typing the command sh latest-dnsonly
Flushing DNS Cache on your system.
When your computer visits a website for the first time, it stores the website’s DNS information in a local cache.
The instructions unique to particular operating systems are below.
From the command line on a windows operating system type:
From a Linux operating system.
Nscd is a daemon that provides a cache for the most common name service requests
From MAC on the terminal window
Directory Service (DNS) cache - Gather information, statistics, initiate queries, flush the cache. dscacheutil replaces most of the functionality of thelookupd tool provided prior to OS X Leopard.
cPanel’s DNS clustering
cPanel’s DNS clustering allows you to synchronize DNS records between multiple cPanel or cPanel DNS ONLY machines. In order to synchronize your DNS records, all machines in the cluster must be running cPanel or cPanel DNS ONLY versions 8.9 or higher.
When configuring your server cluster, it is important to minimize the amount of hops between servers to create the shortest path possible. When possible, you should link webserver server directly to your dns servers or any other servers you wish to update. Each time a DNS zone is modified, the modification will travel down the path to reach each server in the path. The performance of the system is directly proportional to the length of the path.
Notes:
Synchronize Changes: All changes made on your webserver server will be replicated to any server linked to the webserver in the cluster.
Synchronization is one-way: Changes made on the other server will not be replicated to webserver server unless Synchronize Changes is selected on that server as well.
Standalone: All changes made on webserver server will not replicated to any other server(s).
Authoritative DNS
Each domain has at least one authoritative DNS server that publishes information about that domain and the name servers of any domains subordinate to it. The top of the hierarchy is served by the root nameservers, the servers to query when looking up (resolving) a top-level domain name (TLD).
An authoritative name server can either be a master server or a slave server.
Authoritative DNS is the type of DNS that controls the DNS records for a particular domain. For instance, for serverbuddies.com the authoritative DNS servers are ns1.serverbuddies.com and ns2.serverbuddies.com. They only respond to domains they are in charge of.
Contrast this with Recursive DNS are those servers which will give you and answer for any thing. (Google.com, yahoo.com)
