kernel: martian messages

[Aldo Foot]

I have an old server running on redhat 8.0 (I know... don't ask why).

Recently I've seen lines like the following in /var/log/kernel :

Oct 28 08:53:28 myhost kernel: martian source 255.255.255.255 from
127.0.0.1, on dev eth0
Oct 28 08:53:28 myhost kernel: ll header:
ff:ff:ff:ff:ff:ff:<snipped.unknown.mac.address>

It appears they are related to a network device and not to the linux
machine per se.
I did a web search, but I'm not satisfied with the vague responses for
the question.

what do they mean?

~af