Stub/Passive in OSPF

Saad Ahmed 21 years ago

Your OSPF router has one serial interface, and one Ethernet LAN interface. The subinterface is configured in the following manner:

interface serial 0.122 point-to-point

ip address 192.168.1.1 255.255.255.0

encapsulation frame-relay

frame-relay interface-dlci 122

Your want to allow hosts on your LAN to send and receive data, but you don.t want routing traffic to go through that interface. Which of the following commands should you use to complete your configuration?

A. interface serial 0.122 point-to-point

passive-interface ethernet 0

B. interface ethernet 0

ip address 192.168.12.1 255.255.255.0

passive-interface

C. router ospf 172

area 1 nssa

network 192.168.1.0 0.0.0.255 area 0

network 192.168.12.0 0.0.0.255 area 1

D. router ospf 172

passive-interface ethernet 0

network 192.168.1.0 0.0.0.255 area 0

network 192.168.12.0 0.0.0.255 area 1

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Bob by the Bay 21 years ago

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Doan 21 years ago

I don't see a correct answer.

Doan

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Bob by the Bay 21 years ago

Although area 1 as NSSA reduces LSA traffic from area 0 (doesn't completely eliminate it) it also provides for another router on the Ethernet segment acting as ASBR to pass redistributed routes from another AS/domain as LSA 7 traffic back to area 0 as LSA 5 traffic, choice C may not reduce overall routing protocol traffic through the interface as desired.

Robert

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Bob by the Bay 21 years ago

I'm thinking D works assuming that even though the Ethernet network is a passive interface,network 192.168.12.0 0.0.0.255 area 1 is still advertised in Area 0 via the serial interface while no hellos or LSAs are sent out via the Ethernet.interface.

Robert

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