Example +----------+ +----------+ | | | | eth0| |eth1 eth0| |eth1 -----+ router-A +------------- INTERNET ------------+ router-B +----- | | | | | | | | +----+-----+ +----+-----+ | | |lo0 |lo0 router-A ======== interfaces { ethernet eth0 { address "172.16.117.128/24" hw-id: 00:0c:29:b0:1d:bb } ethernet eth1 { address "192.168.249.128/24" hw-id: 00:0c:29:b0:1d:d9 } loopback lo { address "9.0.0.1/24"