Day 27 Flashcards - OSPF (Part 2)

What is the formula to calculate OSPF interface cost?

Reference bandwidth / interface bandwidth = cost

What is the default OSPF reference bandwidth?

100 mbps

What is the OSPF cost of an Ethernet (10 mbps) interface with the default reference bandwidth?

10

What is the OSPF cost of a FastEthernet (100 mbps) interface with the default reference bandwidth?

1

What is the OSPF cost of a Gigabit Ethernet interface with the default reference bandwidth?

1

What is the OSPF cost of a 10Gig Ethernet interface with the default reference bandwidth?

1

Configure the OSPF reference bandwidth:R1(config-router)# […]

auto-cost reference-bandwidth megabits-per-second

What is the OSPF cost of a loopback interface?

1

Configure the OSPF cost of an interface:R1(config-if)# […]

ip ospf cost cost

Configure the bandwidth of an interface:R1(config-if)# […]

bandwidth kilobits-per-second

Does the bandwidth command change the speed at which an interface operates?

No(the speed command does)

What is the default OSPF Hello timer on an Ethernet connection?

10 seconds

What is the default OSPF Dead timer on an Ethernet connection?

40 seconds

What is the multicast address for all OSPF routers?

224.0.0.5

OSPF Hello messages are multicast to […]

224.0.0.5

OSPF neighbor states:1. […] / 2. […] / 3. […] / 4. Exstart / 5. Exchange / 6. Loading / 7. Full

DownInit / 2-way

OSPF neighbor states:1. Down / 2. […] / 3. […] / 4. […] / 5. Exchange / 6. Loading / 7. Full

Init2-way / Exstart

OSPF neighbor states:1. Down / 2. Init / 3. […] / 4. […] / 5. […] / 6. Loading / 7. Full

2-wayExstart / Exchange

OSPF neighbor states:1. Down / 2. Init / 3. 2-way / 4. […] / 5. […] / 6. […] / 7. Full

ExstartExchange / Loading

OSPF neighbor states:1. Down / 2. Init / 3. 2-way / 4. Exstart / 5. […] / 6. […] / 7. […]

ExchangeLoading / Full

If no Hello messages have been received, the OSPF neighbor state is […].

Down

If a router receives an OSPF Hello packet but its own router ID is not in the Hello packet, the neighbor state is […].

Init

When an OSPF router receives a Hello packet with its own router ID, the OSPF neighbor state is […].

2-way

OSPF DR/BDRs are elected in the […] neighbor state.

2-way

In which OSPF neighbor state are a Master and Slave determined?

Exstart

In the OSPF Exstart state, which router becomes the Master?

The router with the higher router ID.

In the OSPF Exstart state, which router becomes the Slave?

The router with the lower router ID

In the OSPF […] state, routers exchange DBDs which contain a list of LSAs in their LSDB.

Exchange

OSPF: What does DBD stand for?

Database Description

OSPF: What does LSR stand for?

Link State Request

OSPF: What does LSU stand for?

Link State Update

OSPF: What does LSAck stand for?

Link State Acknowledgement

In the OSPF […] state, routers send LSR messages to request LSAs from their neighbor.

Loading

OSPF LSAs are sent in […] messages.

LSU

In the OSPF […] state, the routers have a full OSPF adjacency and identical LSDBs.

Full

OSPF Message type […] = Hello

1

OSPF Message type 1 = […]

Hello

OSPF Message type […] = Database Description (DBD)

2

OSPF Message type 2 = […]

Database Description (DBD)

OSPF Message type […] = Link-State Request (LSR)

3

OSPF Message type 3 = […]

Link-State Request (LSR)

OSPF Message type […] = Link-State Update (LSU)

4

OSPF Message type 4 = […]

Link-State Update (LSU)

OSPF Message type […] = Link-State Acknowledgement (LSAck)

5

OSPF Message type 5 = […]

Link-State Acknowledgement (LSAck)

Enable OSPF directly on an interface:R1(config-if)# […]

ip ospf process-id area area-id

Configure all interfaces to be OSPF passive interfaces by default:R1(config-router)# […]

passive-interface default