Eu acredito que esta pergunta foi respondida aqui: link
O truque era limpar o campo "Router:" na interface da LAN.
- Go to System Preferences -> Network
- Select your Ethernet device, make sure "Configure IPv4" is set to "Manually", that your subnet mask is set to 255.255.255.0, and that the router box is empty.
Once this is done, netstat -rn should still show the routes for both of the subnets, but only a "link#4" route in place of the default route through 192.168.2.1.