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 220.127.116.11, 18.104.22.168, 22.214.171.124 or 126.96.36.199
If you have a Scheduled Tasks/Cron Job that requires external connections, these will appear from 188.8.131.52 or 184.108.40.206
However, the above addresses are subject to change. So if possible, we'd recommend whitelisting the IP range 220.127.116.11/22.