Setup: Computer with 2 ethernet ports – one as completely isolated network for its clients, the second connecting to the external LAN:
2: eth-intern: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:19:99:77:27:a9 brd ff:ff:ff:ff:ff:ff inet 192.168.32.1/24 brd 192.168.32.255 scope global eth-intern valid_lft forever preferred_lft forever 3: eth-extern: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:19:99:77:23:65 brd ff:ff:ff:ff:ff:ff inet 192.168.17.199/24 brd 192.168.17.255 scope global eth-extern valid_lft forever preferred_lft forever No routing between them:
default via 192.168.17.1 dev eth-extern proto static 192.168.17.0/24 dev eth-extern proto kernel scope link src 192.168.17.199 192.168.32.0/24 dev eth-intern proto kernel scope link src 192.168.32.1 No bridging, no NAT (modules aren't even loaded). Still, clients on the 32 subnet can ping/connect to 192.168.17.199 just fine (nothing behind, though). Why is that?
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