Open Shortest Path First (OSPFv2 and OSPFv3) | 713Enable passive interfacesA passive interface is one that does not send or receive routing information. Enabling passive interfacesuppresses routing updates on an interface. Although the passive interface will neither send nor receiverouting updates, the network on that interface will still be included in OSPF updates sent via otherinterfaces.Use the following command in the ROUTER OSPF mode to suppress the interface’s participation on anOSPF interface. This command stops the router from sending updates on that interface.To enable both receiving and sending routing updates, enter the no passive-interface interface command.When you configure a passive interface, the show ip ospf process-id interface command (Figure 413)adds the words “passive interface” to indicate that hello packets are not transmitted on thatinterface.Command Syntax Command Mode Usagepassive-interface {default |interface}CONFIG-ROUTER-OSPF-idSpecify whether all or some of the interfaces will be passive.Default enabled passive interfaces on ALL interfaces in theOSPF process.Entering the physical interface type, slot, and number enablepassive interface on only the identified interface.• For a Gigabit Ethernet interface, enter the keywordGigabitEthernet followed by the slot/port information(e.g. passive-interface gi 2/1).• For a port channel, enter the keyword port-channelfollowed by a number from 1 to 255 for TeraScale andExaScale, 1 to 32 for EtherScale (e.g. passive-interfacepo 100)• For a SONET interface, enter the keyword sonetfollowed by the slot/port information (e.g.passive-interface so 2/2).• For a 10-Gigabit Ethernet interface, enter the keywordTenGigabitEthernet followed by the slot/portinformation (e.g. passive-interface ten 2/3).• For a VLAN, enter the keyword vlan followed by anumber from 1 to 4094 (e.g. passive-interface vlan2222).E-Series ExaScale platforms support 4094 VLANswith FTOS version 8.2.1.0 and later. EarlierExaScale supports 2094 VLANS.The default keyword sets all interfaces on this OSPF process as passive. The passiveinterface can be removed from select interfaces using the no passive-interfaceinterface command while passive interface default is configured.
