ip ospf demand-circuit — interface
ip ospf demand-circuit no ip ospf demand-circuit
This command tells OSPF that this interface is a demand circuit (i.e., an interface configured for dial-on-demand routing). OSPF will suppress verbose traffic (such as periodic hello packets), thus preventing the circuit from being kept up all the time.
This example configures an ISDN interface as a DDR link for OSPF:
interface bri0 ip address 10.12.1.5 255.255.255.0 encapsulation ppp ip ospf demand-circuit