Implement and Troubleshoot Passive Interface
Passive interfaces controls the advertisement of routing information
Enables suppression of routing updates over some interfaces
Restricts outgoing advertisements with the exception of EIGRP
- EIGRP suppresses the exchange of Hellos
- Does not allow a neighbor to form
Enabled under the routing process
RIP: Prevent the interface from sending RIP advertisements
router rip passive-interface [default] no passive-interface [interface]
EIGRP: Supresses hello messages, preventing a neighbor relationship to form. Stops routing advertisements and incoming routing updates
router eigrp [as] passive-interface [default] no passive-interface [interface] -- router eigrp [NAME] address-family [ipv4/ipv6] unicast autonomous-system [as] af-interface [interface] [no] passive-interface -- router eigrp EIGRP ! address-family ipv4 unicast autonomous-system 1 ! af-interface default passive-interface exit-af-interface ! af-interface GigabitEthernet0/1 no passive-interface exit-af-interface ! topology base exit-af-topology exit-address-family
OSPF: Setting an interface as passive disables the sending of routing updates on that interface, adjacencies will not be formed. The subnet will continue to be advertised to other interfaces.
router ospf [instance] passive-interface [default] no passive-interface [interface]
ISIS: Suppresses the sending of routing updates through the specified interface.
router isis passive-interface [interface] advertise-passive-only