Summary
Your machine answers to TCP packets that are coming from a multicast address. This is known as the 'spank' denial of service attack.
An attacker might use this flaw to shut down this server and saturate your network, thus preventing you from working properly.
This also could be used to run stealth scans against your machine.
Solution
contact your operating system vendor for a patch.
Filter out multicast addresses (224.0.0.0/4)
