====== Dynamic DNS =====

Automatically update your domain when your IP changes.

> //Dynamic DNS keeps your domain pointing to your server even when your IP changes.//

===== Overview =====

If your ISP assigns dynamic IP addresses that change periodically, you need Dynamic DNS (DDNS) to automatically update your domain when your IP changes.

===== When You Need Dynamic DNS =====

You need DDNS if:
  * Your ISP assigns dynamic IP addresses
  * Your public IP changes periodically
  * You don't have a static IP from your ISP
  * You want reliable hosting without paying for static IP

===== How DDNS Works =====

  1. You register a DDNS hostname (e.g., myhome.ddns.net)
  2. An update client runs on your network
  3. When your IP changes, the client notifies the DDNS service
  4. The DDNS service updates the DNS record automatically

===== DDNS Providers =====

**DuckDNS:**
  * Free, up to 5 hostnames
  * Simple setup
  * Good for personal use

**No-IP:**
  * Free tier available
  * Widely supported by routers
  * Good documentation

**Dynu:**
  * Free tier available
  * Many features
  * Good for advanced users

**Cloudflare:**
  * Free if you use their DNS
  * Good integration with other Cloudflare services
  * Requires Cloudflare account

===== Setup DDNS =====

**Sign up for DDNS service:**
  1. Create account with DDNS provider
  2. Create a hostname
  3. Note your credentials

**Configure update client:**

**Router (if supported):**
  1. Log into router admin panel
  2. Find DDNS settings (usually under Advanced)
  3. Select your DDNS provider
  4. Enter hostname, username, password
  5. Enable DDNS
  6. Save and test

**Software client:**
  1. Install DDNS client on server
  2. Configure with your credentials
  3. Set to run automatically
  4. Test IP change detection

**Script-based:**
  1. Create script to check IP
  2. Use cron job to run periodically
  3. Script calls DDNS update API
  4. Logs changes for debugging

===== Testing DDNS =====

  1. Check current public IP
  2. Verify DDNS hostname resolves to that IP
  3. Change your IP if possible
  4. Verify DDNS hostname updates to new IP
  5. Check DDNS service logs

===== References =====

  * [[https://www.noip.com/support/knowledgebase/free-dynamic-dns-getting-started-guide-ip-version|Free Dynamic DNS Setup Guide: No-IP DDNS Explained]]
  * [[https://www.makeuseof.com/is-dynamic-dns-right-for-you-setup-guide/|Why I Use a Dynamic DNS Instead of a Static IP Address]]
  * [[https://www.ionos.com/help/domains/configuring-your-ip-address/set-up-dynamic-dns-with-company-name/|Set up Dynamic DNS with IONOS]]
  * [[https://docs.netgate.com/pfsense/en/latest/services/dyndns/client.html|Configuring a Dynamic DNS Client | pfSense Documentation]]
  * [[https://routerhax.com/setup-ddns/|How to Set Up Dynamic DNS (DDNS) on Your Router]]

===== See Also =====

  * [[hosting:domain:start|Domain Setup Overview]]
  * [[hosting:domain:public_ip|Find Your Public IP]]

Last updated: 2026-06-19
  * [[hosting:start|Return to hosting]]