Hi Sumdumphuc,
Ideally, you should change the 'workgroup' name to match the remainder of your network. For example, if all your Windows computers have their 'workgroup' names set to MYHOMENETWORK, then you should configure the DNS with the same 'workgroup' name. This way, the DNS will appear as a computer in your 'Network Neighborhood'.
If you are using your DNS in a Windows Active Directory environment, I would set the DNS 'workgroup' name to match the NetBIOS name that was assigned during the creation of the first Active Directory (A/D) Domain Controller Forest - not the Active Directory DynamicDNS name (DDNS). For example, if your A/D domain is DNS: corp.terraflora.com and the NetBIOS: TERRAFLORA, I would set the DNS 'workgroup' name to TERRAFLORA.
HTH,