DNS Server Guide
================

The InterWorx Control Panel provides and easy-to-use interface for managing the DNS Service. 

From the DNS Overview page in NodeWorx, server administrators can add DNS servers, edit the DNS zone defaults, and 
manage active DNS services. 

.. contents::

To Manage the Default DNS Servers
---------------------------------

.. note::

   Default DNS servers refer to the hostname of the nameservers that will be used for the domains hosted
   on the server. **If IP addresses are added in these fields, DNS will not work.** 

#. Log into NodeWorx from the browser (https://ip.ad.dr.ess:2443/nodeworx)
#. In NodeWorx, navigate to **System Services > DNS Server > Overviews**

   .. image:: /images/nw-dns-server.png
      :alt: dns server page 

#. Under Default DNS Servers, update the desired fields: 

   .. image:: /images/nw-dns-default-servers.png
      :alt: default dns servers 

   - **Primary DNS**: The first nameserver to be used for requesting zone data for a given zone. For redundancy, a 
     second (though equally authoritative) nameserver is required
   - **Secondary DNS**: The second nameserver to be used for requesting zone data for a given zone. An optional 
     (equally authoritative) third nameserver can be provided for additional redundancy
   - **Tertiary DNS**: Similar to the secondary nameserver, but it is only used if the primary and secondary server fail
   - **Additional DNS**: Additional DNS. These are not required, but provide additional DNS redundancy

#. Click **Update**

To Set the DNS Zone Defaults
----------------------------

#. Log into NodeWorx from the browser (https://ip.ad.dr.ess:2443/nodeworx)
#. In NodeWorx, navigate to **System Services > DNS Server > Overviews**

   .. image:: /images/nw-dns-server.png
      :alt: dns server page 
    
#. Under DNS Zone Defaults, update the desired fields: 

   .. image:: /images/nw-dns-zone-defaults.png
      :alt: dns zone defaults 

   - **Refresh Time**: Sets the number of seconds that a record will be cached before re-checking the primary 
     server. Recommended values are between 1200 (twenty minutes) and 43200 (twelve hours)
   - **Retry Time**: Sets the number of seconds to retry a refresh after the previous refresh attempt fails. 
     Recommended values are between 180 (three minutes) and 900 (fifteen minutes).
   - **Expire Time**: Sets the number of seconds for refresh and retry attempts before the server will stop serving 
      the zone. Recommended values are between 1209600 (two weeks) and 2419200 (four weeks). 
   - **Negative TTL**: Time in seconds for negative answers (NXDOMAIN) from this zone. Suggested values are between 3600 
     (one hour) and 10800 (three hours). Values higher than 86400 (twenty-four hours) should be avoided
   - **Enforce RFC1912 CNAMES**: RFC1912 states "A CNAME record is not allowed to coexist with any other data." 
     In certain circumstances, it may be desired to relax this restriction if the ramifications are understood. However,
     it is enabled by default. 

#. Click **Update** 

To Manage Active DNS Services
-----------------------------

Installing DNS Service on an IP Address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

#. Log into NodeWorx from the browser (https://ip.ad.dr.ess:2443/nodeworx)
#. In NodeWorx, navigate to **System Services > DNS Server > Overviews**

   .. image:: /images/nw-dns-server.png
      :alt: dns server page 
    
#. Under IP Addresses Without DNS Services, select the **checkbox** next to the IP address

   .. image:: /images/nw-dns-install-iterative.png
      :alt: install dns on ip form 

#. From the With Selected dropdown, select **install** 
#. Click **Go** 

Managing DNS Service on an IP Address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

#. Log into NodeWorx from the browser (https://ip.ad.dr.ess:2443/nodeworx)
#. In NodeWorx, navigate to **System Services > DNS Server > Overviews**

   .. image:: /images/nw-dns-server.png
      :alt: dns server page 
    
#. Under Active DNS Services, select the **checkbox** next to the IP address
#. From the With Selected dropdown, select The

   - **Stop**: Stop the DNS Service
   - **Start**: Start the DNS Service
   - **Restart**: Restart the DNS Service
   - **Flush**: Flush the DNS Cache 
   
   .. image:: /images/nw-dns-manage.png
      :alt: manage active dns form 

#. Click **Go**

Removing DNS Service From an IP Address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

#. Log into NodeWorx from the browser (https://ip.ad.dr.ess:2443/nodeworx)
#. In NodeWorx, navigate to **System Services > DNS Server > Overviews**

   .. image:: /images/nw-dns-server.png
      :alt: dns server page 
    
#. Under Active DNS Services (Iterative), click the **checkbox** next to the IP address 

   .. image:: /images/nw-dns-remove-iterative.png
      :alt: remove dns from an ip 

#. From the With Selected dropdown, select **Remove**
#. Click **Go**