I would like to find out if it is possible to have dynamic updates between a Cisco Router's DHCP server and Windows Server 2003's DNS server.



Is it possible for Cisco DHCP Server to send these registrations to a DNS Server on a remote Windows Server?



No, it is not.



With a Windows DNS Server, the client "registers" by writing its address into the DNS file. With a Cisco DHCP, the client does not "register" anything. The DHCP server assigns an address to the client, and stores the information.



You would need to have a process that reads the router config, obtains the DHCP information and then writes it to the DNS Server. The router itself has no mechanism to do this.



No-one has commented on this in the intervening months.  For the benefit of Google Groups and others: A Cisco IOS DHCP server is quite capable of sending Dynamic DNS Updates to a DNS server.  The version 12.3 and later documentation includes a guide to Dynamic DNS Support that has step-by-step guides.