Does the following help ?
They were originally registered in Europe. We are now using these IP addresses here in the US. Those IP address registries shows where the IP addresses was registered not where it is currently being used. Can sometimes be a bit misleading.
Diablo 3 Forums
Just here to confirm that Maskraider is correct. Netherlands is a common one that we see confusion with when a search for the IP is done. These IPs were registered there but this is not the server location.
Diablo 3 Forums
As far as troubleshooting your connection, you may want to perform a WinMTR and a Looking-Glass (when seeing high ping) as suggested here… WinMTR checks your connection from your computer to Blizzard while the Looking-Glass goes from Blizzard to your ISP. Post the reports in your reply,