Network > Dynamic DNS

Dynamic DNS (DDNS) is a service provided by various companies and organizations that allows for dynamic changing IP addresses to automatically update DNS records without manual intervention. This service allows for network access using domain names rather than IP addresses, even when the target’s IP addresses change. For example, is a user has a DSL connection with a dynamically assigned IP address from the ISP, the user can use DDNS to register the IP address, and any subsequent address changes, with a DDNS service provider so that external hosts can reach it using an unchanging domain name.

Dynamic DNS implementations change from one service provider to another. There is no strict standard for the method of communication, for the types of records that can be registered, or for the types of services that can be offered. Some providers offer premium versions of their services, as well, for a fee. As such, supporting a particular DDNS provider requires explicit interoperability with that provider's specific implementation.

Most providers strongly prefer that DDNS records only be updated when IP address changes occur. Frequent updates, particularly when the registered IP address is unchanged, may be considered abuse by providers, and could result in your DDNS account getting locked out. Please refer to the use policies posted on the provider's pages, and abide by the guidelines. SonicWALL does not provide technical support for DDNS providers - the providers themselves must be contacted.

Topics:

•	Supported DDNS Providers

•	Configuring Dynamic DNS

•	Dynamic DNS Settings Table

Supported DDNS Providers

Not all services and features from all providers are supported, and the list of supported providers is subject to change. SonicOS currently supports the following services from four Dynamic DNS providers:

•	Dyndns.org - SonicOS requires a username, password, Mail Exchanger, and Backup MX to configure DDNS from Dyndns.org.

•	Changeip.com - A single, traditional Dynamic DNS service requiring only username, password, and domain name for SonicOS configuration.

•	No-ip.com - Dynamic DNS service requiring only username, password, and domain name for SonicOS configuration. Also supports hostname grouping.

•	Yi.org - Dynamic DNS service requiring only username, password, and domain name for SonicOS configuration. Requires that an RR record be created on the yi.org administrative page for dynamic updates to occur properly.

Additional Services offered by Dynamic DNS Providers

Some common additional services offered by Dynamic DNS providers include:

•	Wildcards - allows for wildcard references to sub-domains. For example, if you register yourdomain.dyndns.org, your site would be reachable at *.yourdomain.dyndyn.org, e.g. server.yourdomain.dyndyn.org, www.yourdomain.dyndyn.org, ftp.yourdomain.dyndyn.org, etc.

•	Mail Exchangers - Creates MX record entries for your domain so that SMTP servers can locate it via DNS and send mail. Note: inbound SMTP is frequently blocked by ISPs - please check with your provider before attempting to host a mail server.

•	Backup MX (offered by dyndns.org, yi.org) - Allows for the specification of an alternative IP address for the MX record in the event that the primary IP address is inactive.

•	Groups - Allows for the grouping of hosts so that an update can be performed once at the group level, rather than multiple times for each member.

•	Off-Line IP Address - Allows for the specification of an alternative address for your registered hostnames in the event that the primary registered IP is offline.

For information on setting up DDNS Profiles, see Configuring Dynamic DNS.