My opensuse box has two NICs, eth1 and eth2. The network physically is delivered by a single cable, but we have to networks on it, so we have two networks on the same physical layer.
Both eth1 and eth2 connects to this physical layer using a simple switch, but they are set up to connect to different networks.
eth1 is set up with IP address like 193.5.x.x
eth2 is set up with IP address 172.19.175.25
My log file is full of messages like:
martian source 255.255.255.255 from 172.19.175.25, on dev eth1
ll header: ff:ff:ff:ff:ff:ff:00:34:52:98:ae:1e:08:00
Sometimes I have similar message but on eth2, and the IP is the IP of eth1 or another computer on this network.
The NICs are set up in a way that the internet is accessed through eth2, and local servers are accessed with eth1. Eth1 also serves as an address to access the computer from the internet.
Basically everything works as intended, except the fact, the the log file is practically unusable because of the millions of martians attacking
I see, that the problem is the two networks somehow mix on the same layer. What can be done? Is there a solution, to stop receiving martians?