These are the IP addresses that may scan your server when it is listed on the website.

208.167.241.190
208.167.241.185
208.167.241.186
208.167.241.183
208.167.241.189
108.61.78.147
108.61.78.148
108.61.78.149
108.61.78.150

After you add the server to the website, it will generally be scanned from the same dedicated scanner. However, it is possible the queries can come from different scanners so we suggest ensuring all of these IPs are able to reach your server to prevent unintended time where the server is listed as "Offline".