Question:

Do you have to configure DNS information on the AMX controller?

Answer:

If the AMX controller is to make any connection to a hostname rather than an IP address, then yes, you need to configure DNS information.  It is assumed the IP address of the controller is set statically otherwise a dynamic address typically receives DNS information automatically.

A Domain Name System (DNS) stores IP addresses much like a phonebook stores phone numbers.  It is much easier to look up a phone number by a name rather than memorize the phone number.  In relation to a phonebook, a DNS server stores IP addresses instead of phone numbers and the related hostname instead of a person's name.  For example, when you type the hostname of "harman.com" into a web browser a DNS server looks for the IP address associated with "harman.com" and provides this IP address back to the web browser in order to reach this website.  This all happens in the background, just like saying "Call John Doe" on your mobile phone.  The phone knows the number previously stored for John and dials it for you.  Hostnames are not just used across the internet but are also used within private company networks (intranets).

There are many types of IP connections where an AMX controller could use an IP address or a hostname.  One of the most common connections would be a hostname for RMS.  (i.e.  http://MyRMSserver.com/rms) Other connections could be directed by code such as the IP_CLIENT_OPEN or a DUET module.  Master-to-Master communication is another IP connection which could use a hostname versus an IP address.

On an AMX controller, if just one connection uses a hostname then DNS information must be entered on the AMX controller.  It is important to be aware of all the various IP connections an AMX controller may be programmed to establish.  If you are unsure, it would be wise to set the DNS information.