3.3.e Implement and troubleshoot passive interface

RIP, OSPF, and EIGRP all support what’s known as passive-interfaces.

Enabling an interface as passive will mean we will not send our hellos out on the interface, but we will advertise the interface’s network into the routing protocol.

for OSPF:

en
conf t
router ospf 1
passive-interface <default | interface>

How do you utilize the passive-interface default? Give an example where all interfaces except for g0/1 should be passive.

router ospf 1
passive-interface default
no passive-interface g0/1
end

How can you verify which interfaces are passive?

show ip protocols