Q41. A Mobile Service Provider would like to design and deploy an Ethernet service which has similar physical link failover/failback characteristics on the active/backup links as the APS/MSP SONET properties. Which Layer 2 services should be considered to address this design feature? 

A. Port-Channel 


C. Flex Link 

D. Ethernet Pseudowires 


Q42. Refer to the exhibit. 

In this network design, where should summarization occur to provide the best summarization and optimal paths during a single-failure incident as well as during normal operation? 

A. a single identical summary for all the branch offices placed on routers 1A, 1B, 2A, and 2B 

B. two summaries on 1A and 1B, and two summaries on 2A and 2B 

C. a single identical summary on 3A and 3B 

D. a single summary on each aggregation device for the branches connected to them 


Q43. Voice traffic between two campus enterprise networks is growing. The network designers decide to add a second 10-Mb Metro Ethernet service parallel to their original 10-Mb service in order to provide more bandwidth and diversity. The QoS profile will be the same on the new 10-Mb service due to the voice stability on the first Metro Ethernet link. When the second link is added to the OSPF domain, which traffic design consideration would have the most impact on the voice traffic when both links are active? 

A. per-destination IP address basis 

B. per-flow basis 

C. per-packet basis 

D. per-source IP address basis 


Q44. A network designer wants to improve a company network design due to multiple network crashes. Which technology would allow for the restore of a network connection without informing the Layer 3 protocol? 

A. Bidirectional Forwarding Detection 

B. automatic protection switching 

C. UniDirectional Link Detection 

D. Ethernet OAM 


Q45. You are a network designer and are responsible for ensuring that the network you design is secure. How do you plan to prevent infected devices on your network from sourcing random DDoS attacks using forged source addresses? 

A. ACL-based forwarding 

B. ACL filtering by destination 

C. Unicast RPF loose mode 

D. Unicast RPF strict mode 


Q46. In which two ways is a network design improved by the inclusion of IP Event Dampening? (Choose two.) 

A. reduces processing load 

B. provides sub-second convergence 

C. improves network stability 

D. prevents routing loops 

E. quickly detects network failures 

Answer: AC 

Q47. Refer to the exhibit. 

You must ensure that both core A and core B devices have only the minimum information required for reaching the spoke routers yet maintain full reachability during network failures. 

Which of the following design solutions accomplishes these requirements? 

A. Route summarization, with specific route leaking on hubs A and B 

B. Route summarization, with GRE tunnel on hubs A and B 

C. Implement PfR enhancements on hubs A and B. 

D. Implement ODR for hub-to-spoke routing. 


Q48. Refer to the exhibit. 

Which technology could be used in this design to provide link recovery and high traffic capacity? 

A. Rapid PVST 


C. PAgP 

D. Flex Links 


Q49. Refer to the exhibit. 

If IEEE 802.1w is in use for this network design, what are two locations where spanning-tree root can be placed to ensure the least-disruptive Layer 2 failover for clients within VLANs 3 and 4? (Choose two.) 

A. Switch A 

B. Switch B 

C. Switch C 

D. Switch D 

Answer: CD 

Q50. You are the lead network designer hired by Service Provider XYZ to deploy CoS functionality on the core MPLS network (P routers). The goal of the network design is to provide a complete CoS solution to all customers that purchase services such as dedicated internet access, MPLS L3VPN, and L2VPN (pseudowire). Service Provider XYZ has these design requirements: 

The network supports four service queues with equal treatment for delay, jitter, and packet loss. 

Queues are numbered 0-3, where 0 is the default queue. 

Three queues have one treatment. 

One queue has either one or two treatments. 

How would you design your solution to map the DSCP value properly so that the traffic is assigned to the respective queues in the Service Provider XYZ MPLS core network? 

A. Classify traffic according to DSCP value into appropriate P router queues. 

B. Map the appropriate DSCP value into the EXP field based on the number of queues in the MPLS P routers. 

C. Map the appropriate DSCP value into the EXP field based on the number of queues in the MPLS PE routers. 

D. Based on the DSCP value, traffic is mapped automatically into appropriate queues in the MPLS CE routers.