According to Wikipedia:
- Dynamic DNS (DDNS or DynDNS) is a method of automatically updating a name server in the Domain Name System (DNS), often in real time, with the active DDNS configuration of its configured hostnames, addresses or other information.
- The term is used to describe two different concepts. The first is "dynamic DNS updating" which refers to systems that are used to update traditional DNS records without manual editing. These mechanisms are explained in RFC 2136, and use the TSIG mechanism to provide security. The second kind of dynamic DNS permits lightweight and immediate updates often using an update client, which do not use the RFC2136 standard for updating DNS records. These clients provide a persistent addressing method for devices that change their location, configuration or IP address frequently.
For RFC2136 there is #Update clients.from . For dynamic DNS services there are several packages available, see
If the device needing DDNS sits behind a router, you should first check if the router itself can update any DDNS services. Although the selection of services may be limited, there are several advantages to using the router: it will probably be easier to set up, will require little to no maintenance, and will have no downtime (if the router is down you will not have Internet anyway).
Note that some dynamic DNS providers do not require a dedicated client and can be updated with.
- ddclient — Update dynamic DNS entries for accounts on many dynamic DNS services.
- inadyn-fork — Dynamic DNS client with SSL/TLS support.
- http://troglobit.com/inadyn.html || AUR, AUR
- inadyn-mt — A simple dynamic DNS client based on inadyn.
- ndyndns — Supports DynDNS and Namecheap.
- duckdns — Update your DuckDNS.org entries from your computer with systemd.
- https://www.duckdns.org/ || AUR
- noip — Dynamic DNS Client Updater for no-ip.com services.
- petrified — Bash client to update dynamic DNS at freedns.afraid.org.
The configuration can be tested by running
ddclient with the
# ddclient -daemon=0 -noquiet -debug
|No-IP||Use protocol |
|nsupdate.info||Use protocol |
Use an external website to determine IP address
If ddclient is unable to detect your IP address, you can configure ddclient to fetch your IP from an external webpage such as checkip.dyndns.org. This address is used by default when
use=web is specified. It is also recommended to increase the check interval to avoid frequent requests to the IP check service:
daemon=900 # obtain IP address from web status page use=web
An alternative IP check service can be specified with the
daemon=900 # obtain IP address from web status page use=web, web=myonlineportal.net/checkip
Starting ddclient after networking is up
If you find that ddclient is unable to update your IP properly, it may be that the ddclient process is starting before networking is up. To fix it, you can edit the unit file to depend on
# systemctl edit ddclient.service
[Unit] After=network-online.target Wants=network-online.target
Additional configuration for
network-online.target may be necessary, see .
Other DDNS providers are not compatible with ddclient so updating your IP with them may require a special tool or some custom scripting. Remember that if the service allows you to update your IP using the command line, you can automate the process using tools such as cron or systemd/Timers.