Ignite has been shown to have significant issues with port scanning tools hitting it's ports which can cause Ignite nodes to go down and thus causing instability to the cluster it is serving. There are two Ignite clusters in Fusion 4.x -- 1 for the proxy and 1 for API/Connectors-classic components.
The ports you should be focused on can be found by looking at what ports are being listened to via netstat -tpl | grep <componentPID>
These should be around the 47100+ range and 49100+ range. Different installations might not be the exact same ports
The possible solutions are:
1) Don't scan from inside the internal network that Fusion is on. The scanning could be done externally and thus should be blocked by a firewall
2) Don't scan those specific ports if you insist on scanning from inside the network