Interactive Configuration
Enter configuration mode, using “configure term”
Prompt gives a hint about where you are:
router#configure term
router(config)#ip classless
router(config)#ip subnet-zero
router(config)#int e0/1
router(config-if)#ip addr n.n.n.n m.m.m.m
router(config-if)#no shut
router(config-if)#^Z