Cisco: Advanced Level

Blog Sections:

Main Page | Beginner | Intermediate | Advanced | Other Article

This section is the review material consisting of labs which should be solved in 10 minutes or less. It also contains questions regarding particular technology.

List of OSPF Labs

Problem 01 | Problem 02 | Problem 03 | Problem 04 | Problem 05
Problem 06 | Problem 07 | Problem 08 | Problem 09 | Problem 10
Problem 11 | Problem 12 | Problem 13 | Problem 14 | Problem 15
Problem 16 | Problem 17 | Problem 18 | Problem 19 | Problem 20
Problem 21 | Problem 22 | Problem 23 | Problem 24 | Problem 25
Problem 26 | Problem 27 | Problem 28 | Problem 29 | Problem 30
Problem 31 | Problem 32 | Problem 33 | Problem 34 | Problem 35

The startup configuration can be downloaded here. Alternatively, you can configure these devices based the the topology diagram presented below (not such a bad idea). The physical topology for this and other labs can be found on the main page. If you want to download it the save the content of the link below (I don't have GNS3 only Dynagen format):

Download: topology diagrams and .net map.

Here’s your layer 2 Topology diagram. Click on image to enlarge it.

Layer 2 Topology Diagram.

Layer 3 Topology Diagram.

Your Feedback
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.

OSPF Problem 6

Previous | 10 Minute Labs: OSPF | Next

Try to solve the lab problem in 10 minutes or less.

• Change OSPF configuration of R1′s, R2′s Ser0/0 interfaces, and R3′s Ser0/0.123 sub-interface  you have done in the previous lab such that the Frame-Relay network does not need DR/BDR election.
• R1 should see IP address of 172.16.123.2 as the next-hop address for subnets advertised by R3 when using S0/0 interface.
• R3 should see IP address of 172.16.123.2 as the next-hop address for subnets advertised by R1.
• On R3 do NOT use ‘ip ospf network‘ command to accomplish full adjacency with R2.
• Remove all redundant OSPF/Frame-Relay commands configured in the previous lab (problem 5).

Pic.4

Extra Credit

Take as much time as you need to answer the following questions:

1. What other OSPF mode could you use in NBMA hub-and-spoke topology instead of using the default one? Why?
2. What type of destination address is used in this lab as far as OSPF communication is concerned?
3. What Frame-Relay command is NOT required for OSPF mode used in this lab?
4. What are the default timers (hello/dead) while using OSPF mode you have configured in this lab?
5. What is compatible mode with OSPF mode used in this lab?
6. In case of OSPF mode used in this lab, what does LSDB show as far as the following are concerned (assuming default ospf mode): link connected to, link id, link data?

When you have solved the problem check the hint(s) below:

Lab Hint

• R1 should use only one ‘frame-relay’ map statement
• R3 should use default ospf mode of operation on Ser0/0.123

Your Feedback 
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.

OSPF Problem 5

Previous | 10 Minute Labs: OSPF | Next

Try to solve the lab problem in 10 minutes or less.

• Configure OSPF area 0 on Ser0/0 of R1, and R2 using default OSPF mode of operation.
• Enable OSPF area 0 on R3‘s Ser0/0.123 sub-interface and its Loopback0 interface.
• Ensure there is full reachability and full adjacency in Frame-Relay network configured.
• Ensure R3 can ping 10.0.1.1 (R1′s Loopback0) sourced by its Loopback0 interface.

Pic.4

Extra Credit

Take as much time as you need to answer the following questions:

1. What is the default OSPF mode used on NBMA (non-broadcast, multi-access interfaces) links?
2. What is/are compatible OSPF modes with the default mode used on NBMA links?
3. What would you configure to make other OSPF mode to be compatible with NBMA?
4. What are the default timers (hello/dead) used on NBMA links?
5. How are OSPF neighbors discovered on NBMA links?
6. Which OSPF routing context command is required for the routers to establish OSPF communication?
7. What is going to happen if an OSPF router receives a unicast addressed ‘hello’ packet from its OSPF neighbor?
8. What OSPF router roles does NBMA network elect?
9. Which command shows the role of the router on a specific NBMA link?
10. In case of hub-and-spoke NBMA topology, what OSPF role should spoke routers take (justify your answer)?
11. What are the two ways of configuring the required role in a spoke router in NBMA hub-and-spoke topology?
12. What is OSPF next-hop behavior on NBMA links in a hub-and-spoke topology? What do you need to take care of regarding next-hop?
13. In case of non-broadcast OSPF mode, what does LSDB show as far as the following are concerned (assuming default ospf mode): link connected to, link id, link data?

When you have solved the problem check the hint(s) below:

Lab Hint

• Can R3 reach R1‘s Ser0/0 with the default configuration (before you have introduced changes)?
• What NBMA role should the spokes (R1 and R3) play in this configuration?
• Does R3 use 172.16.123.1 address as its next-hop towards 10.0.1.1?

Your Feedback 
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.

OSPF Problem 4

Previous | 10 Minute Labs: OSPF | Next

Try to solve the lab problem in 10 minutes or less.

• Verify which router has become DR in VLAN 27 (most likely it is going to be R2).
• Force the re-election of the DR making sure that previous BDR becomes DR, and previous DR becomes BDR.
• Do NOT shut down any interface to accomplish this.
• Do NOT clear ip ospf process to accomplish this.
• Do NOT reload the router(s) to accomplish this.

Pic.3

Extra Credit

Take as much time as you need to answer the following questions:

1. Are DR/BDR roles pre-emptive? Why?
2. What would be the quickest and causing least interruption way of changing the OSPF role in a broadcast network?
3. In Case of the same OSPF port priority, what parameter is going to determine DR/BDR election?
4. What would happen if neither SW1 nor R2 became DR? Check your answer in practice.

When you have solved the problem check the hint(s) below:

Lab Hint

• Do you really need a hint here? Looking for a kindergarten? Wrong place dude.

Your Feedback 
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time. 

OSPF Problem 3

Previous | 10 Minute Labs: OSPF | Next

Try to solve the lab problem in 10 minutes or less.

• On SW1 enable OSPF area 27 on VLAN 27 and Loopback0 interfaces.
• Do NOT use ‘network‘ statement or redistribution to accomplish the task.
• On SW2 and R5 enable OSPF area 215 on their Loopback0 and all interfaces with VLAN 215 membership. Use ‘network‘ statement with the most specific wildcard mask to accomplish this.
• Make sure SW2 is never elected a DR in VLAN 215. R1 should always be elected DR in case interfaces in VLAN 215 came up at the same time.

Pic.3

Extra Credit

Take as much time as you need to answer the following questions:

1. Why does OSPF elect DR/BDR on certain types of networks?
2. In what network types does OSPF elect DR/BDR?
3. Does DR have to have full layer 2 reachability to other OSPF routers connected to the same segment? Why?
4. What do we call a router that is neither DR nor BDR?
5. If there are four routers connected to the same broadcast segment (the same broadcast domain), what are going to be OSPF states negotiated between them?
6. In case of broadcast OSPF mode, what does LSDB show as far as the following are concerned (assuming default ospf mode): link connected to, link id, link data?
7. What IP address is used when sending updates towards DR/BDR?

When you have solved the problem check the hint(s) below:

Lab Hint

• Does R5 see R1 as the DR and SW2 as DROTHER?

Your Feedback 
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.

OSPF Problem 2

Previous | 10 Minute Labs: OSPF | Next 

Try to solve the lab problem in 10 minutes or less.

• Enable OSPF area 215 on the link of R1 in VLAN 215 (Fa0/1).
• Enable OSPF area 27 on the link of R2 in VLAN 27 (Fa0/0).
• Use ‘network‘ statement with wildcard mask that matches the network mask of the interface.

Pic.2

Extra Credit

Take as much time as you need to answer the following questions:

1. What are the benefits of using OSPF multiple area topology?
2. What do we call area 0 in OSPF multiple area topology?
3. In the OSPF lab completed, what do you call R1 and R2 (routers connected to area 0 and other area)?
4. What are LSA types: 1, 2, 3, 4, 5, 7 and what do they communicate in OSPF domain?
5. What do we call an OSPF router whose all links belong to a single area?
6. What do we call an OSPF router whose all links belong to an area 0?

When you have solved the problem check the hint(s) below:

Lab Hint

• Does R1 see 172.16.27.0/24 in its routing table?
• Does R2 see 172.16.215.0/24 in its routing table?
• Does the ping sourced from Fas0/0 of R1 destined to 172.16.27.2 work?
• How would you verify that VLAN 27 and VLAN 215 links belong to the areas specified in the task?

Your Feedback
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.

OSPF Problem 1

Previous | 10 Minute Labs: OSPF | Next 

Try to solve the lab problem in 10 minutes or less.

Enable OSPF in area 0 between router R1 and R2 on their point-to-point links (Se0/1).

• Advertise Loopback0 address of both routers in area 0.
• Use ‘network‘ command with the most specific wildcard mask to accomplish the task.

Pic.1

Extra Credit

Take as much time as you need to answer the following questions:

1. What are the OSPF modes of operation available in Cisco® IOS™?
2. Which OSPF modes are RFC-based and which are Cisco® proprietary?
3. Which layer of OSI model would you classify OSPF to?
4. OSPF creates three tables. What are these?
5. What is OSPF LSDB?
6. What does the ‘link-state’ in OSPF describe?
7. What is OSPF hello packet and what is/are its purpose(s) in OSPF domain?
8. What are the two link-local multicast addresses reserved for OSPF communication?
9. What OSPF parameters must match in OSPF packet to establish full adjacency?
10. What is the default destination address OSPF uses to send ‘hello’ packets on point-to-point links?
11. What are the five packet types OSPF uses to communicate? What do they do?
12. Which command would you use to verify OSPF-enabled interfaces (do not use ‘show run’)?
13. Which command would you use to verify the state of the OSPF neighbor?
14. What is a ‘router id’ in OSPF?
15. How does OSPF selects its ‘router id’?
16. Is OSPF ‘router id’ pre-emptive?
17. Can you provide at least three commands to display OSPF router id (what are these)?
18. What would happen if you tried to enable OSPF protocol in a router that has not a single IP address configured?
19. Which command would you use to display LSDB?
20. How many point-to-point links does an OSPF router advertise according to LSDB?
21. What are the default timers (hello/dead) used on point-to-point links?
22. What is/are other OSPF modes of operation that are compatible with the default one used on p2p links?
23. What do you need to configure to make other mode(s) compatible with point-to-point mode?
24. Which DBD parameter must match between OSPF neighbors to get past 2-way state?
25. What is the type of LSA (name and number) that describes the links to other routers in the same area?
26. Which command would you use to display LSDB entries about LSA type 1?
27. In case of point-to-point OSPF mode, what does LSDB show as far as the following are concerned (assuming default ospf mode): link connected to, link id, link data?

When you have solved the problem check the hint(s) below:

Lab Hint

• Does the ping from 10.0.1.1 towards 10.0.2.2 work?

Your Feedback
If you find these labs useful, I would appreciate your feedback. Please send me an email as per following: 

Address: linuxed.jr at gmail.com

Subject: ten minute lab

Answers to the following questions:

1. Would you be interested in receiving answers to the TEN MINUTE LABS?

[yes/no]

2. If 'yes' to the first question: what format of the answers would you be interested in?

a) videos on youtube

b) this blog

c) both

d) other: (provide the format)

Thank you for your time.