Due to the distributed nature of our network, the IP address your site uses to make outbound connections will differ from the IP the domain resolves-to, and hence inbound traffic routes through.
External connections made by shared websites will appear as from either 18.104.22.168, 22.214.171.124, 126.96.36.199 or 188.8.131.52
If you have a Scheduled Tasks/Cron Job that requires external connections, these will appear from 184.108.40.206 or 220.127.116.11
However, the above addresses are subject to change. So if possible, we'd recommend whitelisting the IP range 18.104.22.168/24 and 22.214.171.124/24.