Dynamic Dns is useful when your computer or server's ip address changes often. The dynamic dns service will keep the domain name's dns up-to-date with your current ip address.
Setup Dynamic Dns
- Find a free dynamic dns provider and configure the service on your router or computer
- Use a CNAME to point your domain or subdomain to your new dynamic dns hostname.
Keep in mind that dns record caching still applies to dynamic dns since it's modifying the ip address in dns when a change occurs. However, since only the dynamic dns hostname is changing, the TTL on that hostname matters most.
Dynamic Dns Alternatives
Dynamic DNS use has dropped significantly over the past few years due to several reasons:
Broadband Connections
Most internet users now have access using broadband connections, which use semi-static ip addresses that rarely change (although they can). You could manually change the ip address when needed.
Static IP Addresses
Most broadband providers now offer static ip addresses for an additional fee, which is always better than using Dynamic DNS.