Dynamic DNS for Shared Hosting – Does it exist

domain-name-systemdynamic-dnsdynamic-ipshared-hosting

It seems that certain home router firmware is designed to work with Dynamic DNS services (e.g. noip & dyndns) to serve a subdomain from a server behind a consumer ISP. On a similar note, are there any dynamic dns services that will work with a shared web hosting account?

Example

For instance, Dreamhost has an API that can retrieve a domain name's IP address. In theory, the dynamic DNS service would periodically make a request to the Dreamhost API for the website's IP address. If the IP address on Dreamhost changes, the DNS host would automatically make the necessary changes to the zone file for that website as soon as it notices a discrepancy.

Why?

In the past, I had paid for a static IP address on a shared host, my domain name was registered at GoDaddy and the nameserver was set to EveryDNS. Due to catastrophic hardware failure at the shared host, my site was moved and the IP address changed.

In the example setup above, the DNS records would have automatically updated. Instead, I had to manually update my A record.

Question Summary

  1. Is there a Dynamic DNS hosting
    service and shared web host that
    will allow this?

  2. Is the solution
    proposed in the above example
    viable?

  3. Bonus (at the risk of exposing my ignorance on this subject): are there any other
    ways, outside of DNS, to detect the
    IP address for a website? Perhaps a
    script in your shared hosting
    directory could detect an IP change
    and notify the DNS host?

Thanks in advance!

Best Answer

You've already mentioned DynDNS, it sounds like all you're missing is the client. They mention a couple linux-compatible clients on their website.

  • ddclient
  • inadyn

Using either of these in combination with a dynamic DNS service should accomplish what you want.

I originally assumed that your shared hosting would provide you with shell access. Without shell access, things get a bit tricky. First, you need some way to run a script periodically. Some web apps implement "fake cron" by calling a routine on every page load, but that won't help when your site isn't accessible. That means you need access to the crontab.

If you have the ability to run a task periodically, you could develop a script that sends the new IP address to another host you control, which is also the authoritative DNS. The receiving host would use the new IP address to update the zone file, then reload the DNS configuration.

TL;DR No, I don't know of any service that already provides this.

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