strange packet denial

[dzpost@dedekind.net]

The following report of a denied packet has been appearing about once
or twice a day in my system logs:

Jul  4 10:12:48 gateway kernel: Packet log:
  input DENY eth0 PROTO=2 0.0.0.0:65535 224.0.0.2:65535
  L=32 S=0x00 I=19572 F=0x0000 T=1 O=0x00000494 (#5)

My question is:  What does this mean?  This was on my gateway/firewall
machine on a small home network, and eth0 is my internal interface.

I think I understand why the packet is being blocked, but I'm more
more concerned with what it is and where it's coming from.  What does
it mean for the source address to be 0.0.0.0?  And what is 224.0.0.2?

This machine is running Debian 2.2 (potato) with kernel 2.2 using
ipchains.  My internal net uses the 192.168.x.x address range.

Thanks for any help.

--
David Zelinsky
dzpost@dedekind.net