It is used in routers and Internet gateways to automate the task of keeping your DNS record up to date with any IP address changes from your ISP. It can also be used in installations with redundant backup connections to the Internet.

Inadyn can maintain multiple host names with the same IP address, and has a HTTP/HTTPS based IP detection which runs well behind a NAT router.

Selected DDNS providers are supported natively, see inadyn(8) for the complete list. Other providers can be supported using the generic DDNS plugin. Some of these services are free of charge for non-commercial use. Others take a small fee but provide more domains to choose from.