If you are using Cloud 2 (https://cloud2.beyondsecurity.com/) or Cloud 3 (https://cloud3.beyondsecurity.com/), you must whitelist the following IP addresses to use external scans:
Cloud 2
- 50.112.117.210
- 54.244.94.129
- 50.18.47.202
- 52.40.66.12
- 54.193.253.63
Cloud 3
- 54.246.96.88
- 54.217.247.24
- 46.137.119.184