Windows 2000 includes support for dynamic updates to DNS as described in RFC 2136. Every time there is an address event (new address or renewal), the DHCP client sends option 81 and its fully qualified name to the DHCP server, and requests the DHCP server to register a DNS pointer resource record PTR RR on its behalf. The dynamic update client handles the A RR registration on its own. This is done because only the client knows which IP addresses on the host map to that name. The DHCP server may not be able to properly do the A RR registration because it has incomplete knowledge. However, the DHCP server can be configured to instruct the client to allow the server to register both records with the DNS. Registry parameters associated with the dynamic update DNS client are documented in Appendix C. The Windows 2000 DHCP server handles option 81 requests as specified in the draft RFC10 . If a Windows 2000 DHCP client talks to a down-level DHCP server that does not handle option 81, it registers a PTR RR on its own. The Windows 2000 DNS server is capable of handling dynamic updates. Statically configured (non-DHCP) clients register both the A RR and the PTR RR with the DNS server themselves.