While testing out VMware’s Network Insight I noticed a large amount of source IPs showing up as 240.240.240.240. At first I didn’t recognize that address, especially since it’s a class E range.

According to VMware’s KB it’s a placeholder IP for sets of IP > 5000 addresses in order to prevent system load from becoming too high.

Further details are listed below in the article.

VMware KB: vRNI flows show IP address 240.240.240.240 (2150713)