Jeremy's IT Lab CCNA OSPF (Part 2) Day 27

Configure all interfaces to be OSPF passive interfaces by default:

R1(config-router)# [...]

passive-interface default

Configure the bandwidth of an interface:

R1(config-if)# [...]

bandwidth kilobits-per-second

Configure the OSPF cost of an interface:

R1(config-if)# [...]

ip ospf cost cost

Configure the OSPF reference bandwidth:

R1(config-router)# [...]

auto-cost reference-bandwidth megabits-per-second

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

No

(the speed command does)

Enable OSPF directly on an interface:

R1(config-if)# [...]

ip ospf process-id area area-id

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

Init

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

Down

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

Exchange

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

Loading

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

Full

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 which OSPF neighbor state are a Master and Slave determined?

Exstart

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

2-way

OSPF Hello messages are multicast to [...]

224.0.0.5

OSPF LSAs are sent in [...] messages.

LSU

OSPF Message type 1 = [...]

Hello

OSPF Message type 2 = [...]

Database Description (DBD)

OSPF Message type 3 = [...]

Link-State Request (LSR)

OSPF Message type 4 = [...]

Link-State Update (LSU)

OSPF Message type 5 = [...]

Link-State Acknowledgement (LSAck)

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

2

OSPF Message type [...] = Hello

1

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

5

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

3

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

4

OSPF neighbor states:

1. [...]

2. [...]

3. [...]

4. Exstart

5. Exchange

6. Loading

7. Full

Down

Init

2-way

OSPF neighbor states:

1. Down

2. [...]

3. [...]

4. [...]

5. Exchange

6. Loading

7. Full

Init

2-way

Exstart

OSPF neighbor states:

1. Down

2. Init

3. 2-way

4. [...]

5. [...]

6. [...]

7. Full

Exstart

Exchange

Loading

OSPF neighbor states:

1. Down

2. Init

3. 2-way

4. Exstart

5. [...]

6. [...]

7. [...]

Exchange

Loading

Full

OSPF neighbor states:

1. Down

2. Init

3. [...]

4. [...]

5. [...]

6. Loading

7. Full

2-way

Exstart

Exchange

OSPF: What does DBD stand for?

Database Description

OSPF: What does LSAck stand for?

Link State Acknowledgement

OSPF: What does LSR stand for?

Link State Request

OSPF: What does LSU stand for?

Link State Update

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

40 seconds

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

10 seconds

What is the default OSPF reference bandwidth?

100 mbps

What is the formula to calculate OSPF interface cost?

Reference bandwidth / interface bandwidth = cost

What is the multicast address for all OSPF routers?

224.0.0.5

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

1

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 loopback interface?

1

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

10

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

2-way