Configuring a Custom Domain impacts nearly all of the ways that users will connect to your site, whether through the web, the API, WebDAV or FTPS. Because of that, making changes to your custom domain can be a disruptive event. We recommend you plan the switch for a time period where your site has minimal usage, such as a night or weekend.

Preparation For Switching Custom Domain

With planning, it is possible to update with minimal downtime, but there will always be a small period (about 5 to 15 minutes) when the old custom domain is not guaranteed to work and the new custom domain is not yet complete.

This downtime is due to 2 things: registering your SSL certificate (if we are registering it), and a brief time delay where some of our edge servers will serve your old domain's certificate and others will serve your new domain's certificate.

To minimize downtime, you can do some preparation work before the switchover. If your new domain is already pointed to a location via DNS, update the Time To Live (TTL) values on the existing DNS to a low value, such as 60 seconds. This will tell DNS servers across the internet to prepare for a change in the destination of this domain. This step needs to be performed ahead of time, ideally 2-3 days ahead of time, to allow the maximum impact.

If you will be providing your own SSL certificate, upload your new certificate prior to changing the custom domain. (If you will be using a certificate provided by Files.com, you may skip this step. We will generate the new certificate automatically when you change the custom domain.) This step may also be performed in advance of the move.

Switching Your Custom Domain

When ready to switch, create CNAME records for the new domain at your DNS provider. They will point to the same locations as your existing custom domain CNAME records. As soon as you're able to resolve the new CNAMEs, change the custom domain setting in Files.com, and wait for the changes to take effect.

If you are using dedicated IP addresses, you'll need to update your CNAME entries within 5 days of removing the old setting to keep the same dedicated IP addresses. If the CNAME entries for your new custom domain are not set up properly within that 5-day period, your dedicated IPs will be released to be used by other customers.

If you are using your own SSL certificate for the new custom domain, activate it after updating the domain setting.

On the following day after your switchover, you may update the Time To Live (TTL) values on your domain's DNS records to a higher value, such as 300. We strongly recommend leaving the TTL value at 60 seconds because the performance increase provided by large TTL values is negligible compared to being able to respond quickly to changes.

Effects of Changing Custom Domain

Several features depend upon your configured custom domain, so changing the custom domain will have several effects.

Auto-Generated Links

As soon as you update the site setting to indicate the new custom domain, your site will update any Share Link or Inbox URL to reflect the new domain. Existing links will either not work, if the old CNAME entries no longer resolve to your site, or they will cause SSL errors, as the certificate no longer matches the old link address.

Custom User Namespace

Changing your custom domain does not affect your globally unique usernames configuration. If you've already enabled a custom namespace for your users, you will retain that setting after changing your custom domain.

Users with Yubikey / FIDO Authentication

These types of two-factor authentication are tied specifically to the login domain of your site. If you change your site's custom domain settings, every user with this type of 2FA enabled will need to remove their existing 2FA settings and re-configure them. This is baked into the FIDO standards requirement for devices to generate site-specific public/private key pairs, which Files.com follows.

If changing your site settings would impact users, you'll see a message similar to this one when you attempt to change the domain: