pc1[type]=generic pc2[type]=generic pc3[type]=generic pc4[type]=generic r1[type]=gateway r2[type]=gateway r3[type]=gateway r4[type]=gateway pc1[eth0]=lan1 pc2[eth0]=lan2 pc3[eth0]=lan3 pc4[eth0]=lan4 r1[eth0]=lan1 r1[eth1]=link12 r1[eth2]=link14 r2[eth1]=link12 r2[eth0]=lan2 r2[eth2]=link23 r3[eth1]=link23 r3[eth0]=lan3 r4[eth0]=lan4 r4[eth1]=link14