For quite some time I wanted to run a local DNS server so I don’t have to remember IP addresses. Yes, there’s many, it’s not my memory.
In the huge amount of instructions I was unable to find exactly what I needed. Therefore I will post my configuration that might be helpful for you.

NOTE: The Synology DNS server does not automatically Dynamic A Records at the moment.
Result: devices using DHCP will not automatically appear in the DNS server. An iPad called “myipad” with domain “myhome.net” that gets an IP address via DHCP will not be reachable via “myipad.myhome.net”.
The DNS server cannot automatically ‘create’ an A-record with the device name and IP address. thread

Setup

Network: 10.1.1.0/24 (255.255.255.0)
NAS: 10.1.1.99
I don’t have an official domain for my local network but decided to use “myhome.net”
Best practice: probably use a “.local” domain as this will never be resolved on the internet, will not cause a conflict etc.

Master Zone: Forward

Zone settings
Zone ID: myhome.net
Domain name: myhome.net
Status: Enable
Serial format: Integer
Enable Zone Transfer Rule: unchecked
Limit Source IP service: unchecked
                         You add your local subnet here (for example: 10.1.1.0 – 255.255.255.0)

SOA record  Hostname: ns.myhome.net

RESOURCE RECORDS

myhome.net            NS  ns.myhome.net
ns.myhome.net         A   10.1.1.99
somedevice.myhome.net A   10.1.1.21

Master Zone: Reverse

Zone settings
       Zone ID: 1.1.10.in-addr.arpa.
       Domain name: 1.1.10.in-addr.arpa.
Status: Enable
Serial format: Integer
Enable Zone Transfer Rule: unchecked
Limit Source IP service: unchecked
                         You add your local subnet here (for example: 10.1.1.0 – 255.255.255.0)

SOA record   Hostname: ns.1.1.10.in-addr.arpa

Resource records reverse

1.1.10.in-addr.arpa.    NS   ns.myhome.net
99.1.1.10.in-addr.arpa. PTR  ns.myhome.net
21.1.1.10.in-addr.arpa. A    somedevice.myhome.net