ifconfig should set up corresponding routes automatically

In JNode, you have to:
ifconfig eth-pci(0,17,0) 192.168.1.5
route --add 192.168.1.0 eth-pci(0,17,0)
route --add 0.0.0.0 eth-pci(0,17,0) 192.168.1.1 #the gateway
resolver --add 208.67.222.222 #DNS

In Linux, you can set /etc/network/interfaces with all that info at once. You can also manually do:
ifconfig eth0 192.168.1.5 netmask 255.255.255.0 gw 192.168.1.1
And it will do the equivalence of all 3 commands above (all apart from DNS).
JNode should support that syntax, too.