400-101 Exam - CCIE Routing and Switching (v5.0)

certleader.com

Q1. In a nonbackbone OSPF area, all traffic that is destined to the Internet is routed by using a default route that is originated by the ABR. Which change in the configuration of the OSPF area type causes traffic from that area that is destined to the Internet to be dropped? 

A. The OSPF area changes from NSSA to totally stubby area. 

B. The OSPF area changes from NSSA to regular area. 

C. The OSPF area changes from stub area to totally stubby area. 

D. The OSPF area changes from stub area to NSSA. 

Answer:

Explanation: 

The ABR for the NSSA generates the default route, but not by default. To force the ABR to generate the default route, use the area <area id> nssa default-information originate command. The ABR generates a Type 7 LSA with the link-state ID 0.0.0.0 and is advertised inside the NSSA. This default route will be propagated inside the NSSA as Type 7 LSA 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13692-21.html#nssas 

Q2. Which three protocols support SSM? (Choose three.) 

A. IGMPv2 

B. IGMPv3 

C. IGMP v3lite 

D. URD 

E. CGMP 

F. IGMPv1 

Answer: B,C,D 

Q3. DRAG DROP 

Drag and drop the fragmentation characteristics on the left to the corresponding protocol on the right. 

Answer:  

Q4. What two values are required to implement an EIGRP named configuration? (Choose two.) 

A. virtual-instance-name 

B. address-family 

C. router-id 

D. subnet-mask 

E. process-id 

Answer: A,B 

Q5. DRAG DROP 

Drag and drop the protocol on the left to the corresponding administrative distance on the right. 

Answer:  

Q6. DRAG DROP 

Drag each SNMP term on the left to the matching definition on the right. 

Answer:  

Q7. Which BGP feature allows BGP routing tables to be refreshed without impacting established BGP sessions? 

A. BGP synchronization 

B. soft reconfiguration 

C. confederations 

D. hard reset 

Answer:

Explanation: 

Clearing a BGP session using a hard reset invalidates the cache and results in a negative impact on the operation of networks as the information in the cache becomes unavailable. Soft reset is recommended because it allows routing tables to be reconfigured and activated without clearing the BGP session. Soft reset is done on a per-neighbor basis. 

Reference: http://www.cisco.com/en/US/products/ps6599/products_data_sheet09186a0080087b3a.ht ml 

Q8. Which option describes how a router responds if LSA throttling is configured and it receives the identical LSA before the interval is set? 

A. The LSA is added to the OSPF database and a notification is sent to the sending router to slow down its LSA packet updates. 

B. The LSA is added to the OSPF database. 

C. The LSA is ignored. 

D. The LSA is ignored and a notification is sent to the sending router to slow down its LSA packet updates. 

Answer:

Explanation: 

How OSPF LSA Throttling Works 

The timers throttle lsa all command controls the generation (sending) of LSAs. The first LSA is always generated immediately upon an OSPF topology change, and the next LSA generated is controlled by the minimum start interval. The subsequent LSAs generated for the same LSA are rate-limited until the maximum interval is reached. The "same LSA" is defined as an LSA instance that contains the same LSA ID number, LSA type, and advertising router ID. 

The timers LSA arrival command controls the minimum interval for accepting the same LSA. If an instance of the same LSA arrives sooner than the interval that is set, the LSA is dropped. It is recommended that the arrival interval be less than or equal to the hold-time interval of the timers throttle lsa all command. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fsolsath.html 

Q9. Refer to the exhibit. 

What kind of load balancing is done on this router? 

A. per-packet load balancing 

B. per-flow load balancing 

C. per-label load balancing 

D. star round-robin load balancing 

Answer:

Explanation: 

Here we can see that for the same traffic source/destination pair of 10.0.0.1 to 14.0.0.2 there were a total of 100 packets (shown by second entry without the *) and that the packets were distributed evenly across the three different outgoing interfaces (34, 33, 33 packets, respectively. 

Q10. What are three required commands when you enable source-specific multicast for addresses in the range 233.0.0.0/8? (Choose three.) 

A. ip multicast-routing 

B. ip igmp version 3 

C. ip pim ssm-range 233.0.0.0/8 

D. ip igmp version 2 

E. ip pim ssm-range default 

F. set routing-options multicast ssm-groups 233.0.0.0/8 

Answer: A,B,C