Is it normal to see destinations that don't belong to my server in the incoming firewall log?

The destinations are from the same dedicated server provider and they do not ping. Their explanation is:

"As you have already correctly tested from your side, the IP-addresses are not reachable, because they are not allocated to any server. Because of this the switch tries to broadcast the packets here"

Aren't switches supposed to be a little smarter? Is this normal? Do I have to do anything about it? Can I do anything about it?

EDIT: Further relevant info. The SRC IPs are blacklisted IPs from around the world. They are not local to this subnet. Also this is the HOST machine for KVM (virtualization). The network interface is in PROMISCUOUS mode. (This is probably required for bridge networking)