In most cases, banner preview pages use a standard subdomain, preview.bannerboo.com.
Obviously, this isn't very attractive to people who'd like to use their customer pages, so it is a good idea to park your own custom subdomain on the preview page to make it appear more professional. So instead of https://preview.bannerboo.com you could be using something like https://preview.mydomain.com.
The following steps will help you park your subdomain (e.g. https://preview.mydomain.com) on your Branded preview page.
1. Create a CNAME record
The CNAME record must point to the custom subdomain that you wish to use (e.g. preview.yourdomain.com) TO our BannerBoo preview page's domain (e.g. preview.bannerboo.com).
The subdomain you'd like to use should be a custom one. You shouldn't use it for your website since when you park the subdomain on the BannerBoo preview page, it will display just BannerBoo instead of your website.
You can ask your hosting provider to set up CNAME records for you if you are not familiar with the process. The point is to direct it from custom subdomain to BannerBoo.
— go to DNS records
— create a record
— choose CNAME type
— enter "preview.mydomain.com" to the Name field
— enter "preview.bannerboo.com." to the Value (Domain, Canonical name) field
— save record
2. Check if the CNAME record has already been applied
It can take up to 24 hours for the change to propagate, although it usually happens in a few minutes after it is set. So once the CNAME is set, make sure that it is already applied globally and propagated. A website such as whatsmydns.net enables you to check this by simply typing in your custom subdomain and striking the Search button. If you see your BannerBoo account URL at all locations, you can move on to the next step.
Alternatively, you can open the custom subdomain in a browser and check if it shows BannerBoo preview page; if so, then the CNAME already points to our servers and the next step can be completed.
3. Configure your BannerBoo preview page with a custom subdomain
Sign in to BannerBoo and go to the Branded settings section. Insert your custom subdomain in the subdomain field without adding any protocol. Upload your logo, favicon, set your branded colors and click on Save.
Within a few minutes, your custom domain should display your branded preview page and you can begin using it.
Instead, it will say something like "DNS probe completed on NXDOMAIN," which means your CNAME setting for the subdomain you entered is incorrect. You can go back to step 1 to rectify the issue.