Exchange 2013 outlook autodiscover

Hi,

I tried searching on the net, not able to find much information.

As outlook 2016 requires autodiscover service, so i have to set it in exchange 2013.

I have set autodiscover URL.

1. i know i have to set a CNAME in my external DNS. 
Do i put the entry "Host" as mail.abc.com? and what should it be pointed to? (the IP address of my exchange server?)

2. Do i also need to set on my internal DNS a Host(A) file named autodisocover as well?

Thank you