This is false negative. To be marked for alert.
Explanation:
The network administrator or network engineer when he or she is analyzing IDS logs and founded the ip address is same on source and destination both in outside side.
So the either TCPIP address has to change to be scanned across the network. Since same IP address is same pinging rate will high and pinging the same workstation or desktop or laptop.
Alert will not generate because both tcpip address same and if pinging is success. Ids logs generates based true negative, true positive and false positive will not generate any alert.