Question 1 What is OSPF?
Question 2 What Is Backbone Area?
Question 3 Why and on what environment do we implement OSPF?
Question 4 Why are loopbacks advertised as /32 host routes in OSPF?
Question 5 Mention some characteristics of OSPF?
Question 6 What is OSPF’s metric? How is it identified in routing table? Does it support redistribution?
Question 7 Explain LSA and its all Types such as LSA 1, 2, 3,4,5,7. When do we use LSA type 6?
Question 8 What is the concept of “auto cost reference-bandwidth” and in what scenarios we should use it?
Question 9 Why it’s known as Link state protocol? How it’s different than EIGRP? What algorithm does it use?
Question 10 Explain Area Border Router?
Question 11 What will happen if we make priority of an OSPF router as “zero”?
Question 12 How do I change the reference bandwidth in OSPF?
Question 13 How does OSPF calculate its’ metric or cost?
Question 14 How Do We Configure OSPF Routing Protocol?
Question 15 What are Different OSPF LSA Types?
Question 16 What are the states used in OSPF when forming neighborship?
Question 17 What Is Autonomous System Border Router?
Question 18 What are different neighbor states in OSPF?
Question 19 Which type of area blocks external route?
Question 20 What algorithm is used by OSPF if equal cost routes exist?
Question 21 What are the multicast IPs used by OSPF? What multicast IP does DR/BDR router and non-DR use?
Question 22 What are the packet types does OSPF use? Explain Hello, Dead Timers, LSA, LSU, LSR packets.
Question 23 What is role of topology and routing table in OSPF?
Question 24 What Is OSPF Router-Id?
Question 25 Does DR/BDR election happen in OSPF Point to Point Network?
Question 26 What are the tables Maintained By OSPF?
Question 27 What is the link-state retransmit interval, and what is the command to set it?
Question 28 What different activities neighbour router perform in OSPF?
Question 29 What is the purpose of the variable IP-OSPF-Transmit-Delay?
Question 30 Is it true that only the static option of the virtual link in OSPF allows discontiguous networks, regardless of the mask propagation properties?
Question 31 On which algorithms OSPF depends? What is the principle behind it?
Question 32 Are the multicast IP addresses mapped to MAC-level multicast addresses?
Question 33 Does the Cisco OSPF implementation support IP TOS-based routing?
Question 34 What is the concept of Virtual-link in OSPF? Can virtual link be formed thru stub area?
Question 35 Does the offset-list subcommand work for OSPF?
Question 36 Can an OSPF default be originated into the system based on external information on a router that does not itself have a default?
Question 37 Briefly explain functioning and working of different OSPF?
Question 38 Can I use the distribute-list in/out command with OSPF to filter routes?
Question 39 How can I give preference to OSPF interarea routes over intra-area routes?
Question 40 What Is The Default Dead Interval?
Question 41 What LSA is used for inter area communication? What LSA type is used for inter protocol communication in OSPF?
Question 42 What are the different OSPF network types and give an example for each?
Question 43 Do I need to manually set up adjacencies for routers on the Switched Multimegabit Data Service (SMDS) cloud with the OSPF neighbor subcommand?
Question 44 Explain the concept of Area Border Router (ABR) and Autonomous System Border Router (ASBR). Can router sitting between area 2 and 3 be called as ABR?
Question 45 How OSPF inter area, external routes are denoted or represented in routing table?
Question 46 When routes are redistributed between OSPF processes, are all shortest path first algorithm (SPF) metrics preserved, or is the default metric value used?
Question 47 Name tables which OSPF maintain?
Question 48 What is the DR/BDR in OSPF? How these are elected and in what scenario?
Question 49 How does Cisco accommodate OSPF routing on partial-mesh Frame Relay networks?
Question 50 Which address-wild-mask pair should I use for assigning an unnumbered interface to an area?
Question 51 What Is The Need For Dividing The Autonomous System Into Various Areas?
Question 52 Can I have one numbered side and leave the other side unnumbered in OSPF?
Question 53 Why do I receive the “cannot allocate router id” error message when I configure Router OSPF One?
Question 54 What Is The Benefit Of Dividing The Entire Network Into Areas?
Question 55 Why do I receive the “unknown routing protocol” error message when I configure Router OSPF One?
Question 56 What Is The Default Hello Interval?
Question 57 What do the states DR, BDR, and DROTHER mean in show ip OSPF interface command output?
Question 58 When I issue the show ip OSPF neighbor command, why do I only see FULL/DR and FULL/BDR, with all other neighbors showing 2-WAY/DROTHER?
Question 59 Why do I not see OSPF neighbors as FULL/DR or FULL/BDR on my serial link?
Question 60 Do I need any special commands to run OSPF over BRI/PRI links?
Question 61 Explain OSPF Timers?
Question 62 Do I need any special commands to run OSPF over asynchronous links?
Question 63 Which Cisco IOS Software release began support for per-interface authentication type in OSPF?
Question 64 Can I control the P-bit when importing external routes into a not-so-stubby area (NSSA)?
Question 65 Why are OSPF show commands responding so slowly?
Question 66 What does the clear ip OSPF redistribution command do?
Question 67 Does OSPF form adjacencies with neighbors that are not on the same subnet?
Question 68 What Are The Steps Required To Change Neighborship Into Adjacency?
Question 69 How often does OSPF send out link-state advertisements (LSAs)?
Question 70 How do I stop individual interfaces from developing adjacencies in an OSPF network?
Question 71 When I have two type 5 link-state advertisements (LSAs) for the same external network in the OSPF database, which path should be installed in the IP routing table?
Question 72 Explain OSPF LSA, LSU And LSR?
Question 73 What problems can cause OSPF neighborship in “down” state?
Question 74 Where does the summarization happen in OSPF? Which command is used for summarization at ABR and at ASBR?
Question 75 Should I use the same process number while configuring OSPF on multiple routers within the same network?
Question 76 I have a router that runs Cisco Express Forwarding (CEF) and OSPF, who does load-balancing when there are multiple links to a destination?
Question 77 What is “Process-id”? Does it have local or global significance? Does it need to be same on OSPF neighbor routers?
Question 78 How does OSPF use two Multilink paths to transfer packets?
Question 79 How can you detect the topological changes rapidly?
Question 80 Explain The Various OSPF States?
Question 81 Can we have OSPF run over a GRE tunnel?
Question 82 Is there a way to manipulate and prefer the Type 3 LSAs to originate from two different areas sent to the non-backbone area?
Question 83 Is there a drop/flap of an OSPF neighborship when changing an OSPF area type from NSSA no-summary to NSSA?
Question 84 Why DR And BDR Are Elected In OSPF?
Question 85 What is the concept of “Area” in OSPF? What is Backbone area, stub area, Totally Stubby Area, Not So Stubby area (NSSA)?
Question 86 In the %OSPF-5-ADJCHG: Process ID, Nbr [ip-address] on Port-channel31 from FULL to EXSTART, SeqNumberMismatch error message, what does SeqNumberMismatch signify?
Question 87 How does ISPF impact or improve the OSPF network?
Question 88 Is there a way to compare Cisco NX-OS/IOS OSPF commands?
Question 89 Is there any feature of OSPF protocol for quick convergence and a slow re-convergence of routes?
Question 90 What does BADSEQNUM in the %OSPF-5-NBRSTATE: OSPF-101  Process 101, Nbr 10.253.5.108 on Vlan7 02 from FULL to EXSTART, BADSEQNUM OSPF log message mean?
Question 91 What will be Hello/Dead timers in network having link capacity of >T1 and <=T1?
Question 92 What Parameters Must Match For Two Routers To Become Neighbors?
Question 93 What is O E1, O E2 letters in OSPF? Which is default external type 1 or external type 2?