Having your WordPress Website connected to a Content Delivery Network offers many benefits for an incredibly low price (I use Amazon CloudFront as my CDN and it costs just a few dollars per month). The biggest benefit is that content is delivered to your Website visitors from a location close to them no matter where your server is located e.g. my Australian visitors have content delivered from Sydney whereas the Amazon servers in the U.S.A. serve content to my U.S.A. visitors. Now that Website load speed is a Search Engine Ranking factor (SEO) it is important that Websites load very quickly.
The three CDNs that I tend to hook most of my clients with are Amazon/AWS CloudFront, MaxCDN and CloudFlare. There are various ways to implement the use of a CDN with WordPress but I’ve found the W3 Total Cache Plugin (W3 TC) to do a great job. Configuring a CDN for the first time can be a bit tricky so getting an error message makes things a bit more complicated ….
Error When Testing NetDNA
Today, when setting up a WordPress Site to use MaxCDN (A.K.A. NetDNA) by configuring W3 TC, I received an error when clicking the ‘Test NetDNA’ button in the CDN settings tab of W3 TC; Error: Unable to purge (Your IP Address is not whitelisted). This is the first time I’ve seen this error so though this post may be of use to others that get this same error message.
The odd thing is that, even although the error appears, the use of the CDN, and the delivery of the content from MaxCDN seems to be absolutely fine.
The Solution to the ‘Unable to Purge’ Error
Unfortunately I don’t know what the solution is to this error but, as mentioned, there doesn’t seem to be a problem with the delivery of the content from the CDN itself. I haven’t managed to find a cause for this error message but I’m not too concerned because of MaxCDN delivering content as would be expected when all works well.