A Warning About DNS Servers
If you previously implemented DNS in your network environment, you may wish to use your existing DNS servers instead of installing new Windows 2000 Servers to function as DNS name servers. You should also keep in mind that DNS in Windows 2000 is dynamic (DDNS). Records and changes to the DNS database can be dynamically updated through the Active Directory. In order for older DNS name servers to function properly with the Active Directory, you should carefully consider these issues:
SRV records. Your DNS server must support SRV records, which are DNS records that map to the name of a server offering a particular service. If your existing DNS server does not support SRV, you must upgrade to a DNS server that does, or else you must delegate the child domains to a DNS server that supports them.
Incremental zone transfer. You will be happier with your DNS server performance if your DNS servers support incremental zone transfers. They update new or changed DNS records between DNS servers without having to replicate the entire zone database file.
RFC 2136 Dynamic Update Protocol. Although not required, Microsoft highly recommends that your DNS servers support Dynamic Update Protocol. This protocol allows for dynamic DNS so that servers and clients can update DNS records dynamically as they occur. Otherwise, the administrator has to update the DNS records manually.
DHCP Support. If you use a DNS server other than Microsoft, you should make certain that the server can support DHCP because DHCP in Windows 2000 can dynamically update client IP address to DNS name mappings.