300-420: Designing Cisco Enterprise Networks (ENSLD)

Question #: 101
Topic #: 1
An architect is working on a design to connect a company’s main site to several small to medium-sized remote branches. The solution must include redundant
WAN links, but the customer has a limited budget and wants the ability to increase the link speed easily in the future. QoS will run on the branch routers, so there is no need for consistent end-to-end QoS. Which solution does the architect propose?

A. dual-homed WAN MPLS with single-edge router
B. dual-homed Internet with a single-edge router running a site-to-site VPN topology
C. dual-homed WAN MPLS and Internet links via dual-edge routers
D. dual-homed Internet with dual-edge routers running a hub-and-spoke VPN topology

Selected Answer: D

Question #: 102
Topic #: 1
An engineer must design a solution to connect a customer to the Internet. The solution will include a Layer 3 circuit with a CIR of 50 Mbps from the service provider. The hand-off from the provider’s switch to the customer’s router is 1Gbps. Which solution should the engineer include to prevent potential issues with choppy voice traffic?

A. Reduce the bandwidth of the connection to the router.
B. Implement hierarchical QoS with a parent policing policy.
C. Implement hierarchical QoS with a parent shaping policy.
D. Add a bandwidth statement to the router interface.

Selected Answer: B

Question #: 103
Topic #: 1
Refer to the exhibit. Customers report low video quality and delays when having point-to-point telepresence video calls between the two locations. An architect must optimize a design so that traffic follows the same path for egress and ingress traffic flows. Which technique optimizes the design?

A. Configure route leaking on the router in area 2.
B. Configure route leaking on the router in area 1.
C. Configure the high metric on the router in area 4.
D. Configure route filter on the router in area 4.

Selected Answer: A

Question #: 104
Topic #: 1
Refer to the exhibit. An engineer is designing a BGP solution for a client that peers with ISP1 for full Internet connectivity and with ISP2 for direct exchange of routes for several third parties. Which action, when implemented on the edge routers, enables the client network to reach the Internet through ISP1?

A. Run an eBGP session within different VRFs for each ISP.
B. Advertise a default route for downstream routers within the client network.
C. Apply the AS-path prepend feature for ISP2.
D. Apply route filtering such that the client advertises only routes originated from its own AS.

Selected Answer: B

Question #: 105
Topic #: 1
An engineer must propose a solution for a campus network that includes the capability to create multiple Layer 3 virtual networks. Each network must have its own addressing structure and routing table for data forwarding. The solution must be scalable to support hundreds of virtual networks and allow simple configuration and management with minimal administrative overhead. Which solution does the engineer recommend?

A. hop-by-hop EVN
B. multihop MPLS core
C. multihop IPsec tunneling
D. hop-by-hop VRF-Lite

Selected Answer: B

Question #: 106
Topic #: 1
An engineer must design a VPN solution for a company that has multiple branches connecting to a main office. What are two advantages of using DMVPN instead of IPsec tunnels to accomplish this task? (Choose two.)

A. support for AES 256-bit encryption
B. greater scalability
C. support for anycast gateway
D. lower traffic overhead
E. dynamic spoke-to-spoke tunnels

Selected Answer: BE

Question #: 107
Topic #: 1
How is Internet access provided to a WAN Edge router that is connected to a MPLS transport link?

A. OMP advertises a default route from a WAN Edge router that is connected to the MPLS and Internet transport networks.
B. Internet access must be provided at the WAN Edge router through either a 4G/5G link or local Internet circuit.
C. An extranet must be provided in the MPLS transport network to allow private traffic to reach the public Internet.
D. TLOC extensions are used to route traffic to a WAN Edge router that is connected to the Internet transport network.

Selected Answer: A

Question #: 108
Topic #: 1
DRAG DROP –
Drag and drop the elements from the left onto the functions they perform in the Cisco SD-WAN architecture on the right.
Select and Place:

Suggestion Answer:

Question #: 109
Topic #: 1
Which method does Cisco SD-WAN use to avoid fragmentation issues?

A. PMTUD is used.
B. Access circuits are configured with 1600 byte MTU settings.
C. Jumbo frames are enabled.
D. Traffic is marked with the DF bit set.

Selected Answer: A

Question #: 110
Topic #: 1
DRAG DROP –
Drag and drop the descriptions from the left onto the corresponding WAN connectivity types and categories on the right.
Select and Place:

Suggestion Answer:

Question #: 111
Topic #: 1
A global organization with several branches hired a network architect to design an overlay VPN solution. The branches communicate with each other frequently.
The customer expects to add more branches in the future. To meet the customer’s security requirements, the architect plans to provide traffic protection using dynamic IPsec tunnels. Which solution should the architect choose?

A. DMVPN
B. EasyVPN
C. L2TP
D. GETVPN

Selected Answer: A

Question #: 112
Topic #: 1
DRAG DROP –
Drag and drop the descriptions from the left onto the corresponding VPN types on the right.
Select and Place:

Suggestion Answer:

Question #: 113
Topic #: 1
A customer requests a VPN solution to connect multiple sites with the company headquarters. All the sites use the same IP subnet. The engineer plans to use
VPLS. Which solution must the engineer include in the design?

A. different VLANs on each site
B. address translation to hide overlapping subnets
C. 802.1Q connectivity on the LAN side of the CE
D. route exchange with the service provider

Selected Answer: C

Question #: 114
Topic #: 1
An ISP provides Layer 3 VPN service over MPLS to a customer with four branches and multiple CE routers at each branch. To exchange the routes that are learned from the CE routers, which BGP address family should the ISP activate among the PE routers?

A. address-family multicast
B. L2VPN EVPN
C. VPNv4 unicast
D. IPv4 unicast

Selected Answer: C

Question #: 115
Topic #: 1
In the SD-WAN underlay network, which WAN Edge VPN ID is defined as the transport VPN and is used to carry control traffic?

A. VPN 0
B. VPN 512
C. VPN 128
D. VPN 256

Selected Answer: A

Question #: 116
Topic #: 1
A company’s security policy requires that all connections between sites be encrypted in a manner that does not require maintenance of permanent tunnels. The sites are connected through a private MPLS-based service that uses a dynamically changing key and spoke-to-spoke communication. Which type of transport encryption must be used in this environment?

A. GETVPN
B. DMVPN
C. GRE VPN
D. standard IPsec VPN

Selected Answer: A

Question #: 117
Topic #: 1
Which PIM mode uses a shared tree only?

A. bidirectional
B. sparse
C. dense
D. source-specific

Selected Answer: A

Question #: 118
Topic #: 1
Which two statements describe source trees in a multicast environment? (Choose two.)

A. Source trees guarantee the minimum amount of network latency for forwarding multicast traffic
B. Source trees create an optimal path between the source and the receivers
C. Source trees use a single common root placed at some chosen point in the network
D. Source trees can introduce latency in packet delivery
E. Source trees can create suboptimal paths between the source and the receivers

Selected Answer: B

Question #: 119
Topic #: 1
Which two best practices must be followed when designing an out-of-band management network? (Choose two.)

A. Enforce access control
B. Facilitate network integration
C. Back up data using the management network
D. Ensure that the management network is a backup to the data network
E. Ensure network isolation

Selected Answer: AE

Question #: 120
Topic #: 1
What is a benefit of using VRRPv3 as compared to VRRPv2?

A. VRRPv3 supports IPv4 and IPv6
B. VRRPv3 supports authentication
C. VRRPv3 supports preemption
D. VRRPv3 supports stateful switchover

Selected Answer: A

Question #: 121
Topic #: 1
A customer is discussing QoS requirements with a network consultant. The customer has specified that end-to-end path verification is a requirement. Which QoS solution meets this requirement?

A. IntServ model with RSVP to support the traffic flows
B. DiffServ model with PHB to support the traffic flows
C. marking traffic at the access layer with DSCP to support the traffic flows
D. marking traffic at the access layer with CoS to support the traffic flows

Selected Answer: A

Question #: 122
Topic #: 1
Which nonproprietary mechanism can be used to automate rendezvous point distribution in a large PIM domain?

A. Embedded RP
B. BSR
C. Auto-RP
D. Static RP

Selected Answer: B

Question #: 123
Topic #: 1
Which QoS feature responds to network congestion by dropping lower priority packets?

A. CBWFQ
B. tail drop
C. WRED
D. strict priority

Selected Answer: C

Question #: 124
Topic #: 1
What is an advantage of designing an out-of-band network management solution?

A. In the event of a production network outage, network devices can still be managed.
B. There is no separation between the production network and the management network.
C. In the event of a production network outage, it can be used as a backup network path.
D. It is less expensive than an in-band management solution.

Selected Answer: A

Question #: 125
Topic #: 1
An engineer is designing a QoS policy that queues excess packets for later transmission. Which mechanism must be included in the design?

A. shaping
B. WRED
C. policing
D. RED

Selected Answer: A

Question #: 126
Topic #: 1
An organization is designing a detailed QoS plan that limits bandwidth to specific rates. Which two parameters are supported by the traffic policing feature?
(Choose two.)

A. violating
B. marking
C. shaping
D. bursting
E. conforming

Selected Answer: AE

Question #: 127
Topic #: 1
An engineer must propose a QoS architecture model that allows an application to inform the network of its traffic profile and to request a particular type of service to support its bandwidth and delay requirements. The application requires consistent and dedicated bandwidth end to end. Which QoS architecture model meets these requirements?

A. DiffServ
B. LLQ
C. WRED
D. IntServ

Selected Answer: D

Question #: 128
Topic #: 1
An engineer is designing a multicast network for a financial application. Most of the multicast sources also receive multicast traffic (many-to-many deployment model). To better scale routing tables, the design must not use source trees. Which multicast protocol satisfies these requirements?

A. PIM-SSM
B. PIM-SM
C. MSDP
D. BIDIR-PIM

Selected Answer: D

Question #: 129
Topic #: 1
An engineer is working for a large cable TV provider that requires multiple sources streaming video on different channels using multicast with no rendezvous point.
Which multicast protocol meets these requirements?

A. PIM-SM
B. PIM-SSM
C. any-source multicast
D. BIDIR-PIM

Selected Answer: B

Question #: 130
Topic #: 1
What is the function of the multicast Reverse Path Forwarding check?

A. It allows for a loop-free distribution tree from the source to receivers.
B. It serves as an Auto RP Mapping agent.
C. It prevents bootstrap messages from reaching all routers.
D. It is used to discover and announce RP-set information.

Selected Answer: A

Question #: 131
Topic #: 1
An architect is designing a multicast solution for a network that contains over 100 routers. The architect plans to create several multicast domains and balance the
PIM-SM traffic within the network. Which technology should the architect include in the design?

A. DVMRP
B. IGMP
C. MOSPF
D. MSDP

Selected Answer: D

Question #: 132
Topic #: 1
An engineer must design a scalable QoS architecture that allows the separation of the traffic into classes based on predefined business requirements. The design must also utilize the differentiated services code points as the QoS priority descriptor value and support at least 10 levels of classification. Which QoS technology should the engineer include in the design?

A. RSVP
B. DiffServ
C. Best Effort
D. InterServ

Selected Answer: B

Question #: 133
Topic #: 1
A network engineer is redesigning a company’s QoS solution. The company is currently using IP Precedence, but the engineer plans to move to DiffServ. It is important that the new solution provide backward compatibility with the current solution. Which technology should the design include?

A. expedited forwarding
B. assured forwarding
C. class selector code points
D. default per-hop behavior

Selected Answer: C

Question #: 134
Topic #: 1
An enterprise customer has these requirements:
✑ end-to-end QoS for the business-critical applications and VoIP services based on CoS marking.
✑ flexibility to offer services such as IPv6 and multicast without any reliance on the service provider.
✑ support for full-mesh connectivity at Layer 2.
Which WAN connectivity solution meets these requirements?

A. VPWS
B. MPLS VPN
C. DMVPN
D. VPLS

Selected Answer: D

Question #: 135
Topic #: 1
When designing interdomain multicast, which two protocols are deployed to achieve communication between multicast sources and receivers? (Choose two.)

A. IGMPv2
B. BIDIR-PIM
C. MP-BGP
D. MSDP
E. MLD

Selected Answer: CD

Question #: 136
Topic #: 1
Refer to the exhibit. A customer needs to apply QoS to the network management traffic passing through the GigabitEthernet 0/2 interface. All eight queuing classes are in use, so the new requirement must be integrated into the existing policy. Which solution must the customer choose?

A. Mark the traffic to DSCP CS6 and assign it to the ROUTING class. Then, prioritize traffic within the class.
B. Mark the traffic to DSCP CS2 and assign it to the ROUTING class. Then, baseline existing queue sizes to determine if additional bandwidth can be provisioned to the ROUTING class.
C. Mark the traffic to DSCP CS4 and assign it to the SIGNALLING class. Then, prioritize traffic within the class.
D. Mark the traffic to DSCP CS5 and assign it to the SIGNALLING class. Then, baseline existing queue sizes to determine if additional bandwidth can be provisioned to the SIGNALLING class.

Selected Answer: B

Question #: 137
Topic #: 1
An architect must address sustained congestion on the access and distribution uplinks of a network. QoS has already been implemented and optimized, but it is no longer effective in ensuring optimal network performance. Which two solutions should the architect use to improve network performance. (Choose two.)

A. Configure selective packet discard to drop noncritical network traffic.
B. Bundle additional uplinks into logical EtherChannels.
C. Utilize random early detection to manage queues.
D. Implement higher-speed uplink interfaces.
E. Reconfigure QoS based on the IntServ model.

Selected Answer: BD

Question #: 138
Topic #: 1
An engineer must design a QoS solution for a customer that is connected to an ISP over a 1Gbps link with a 100Mbps CIR. The ISP aggressively drops all traffic received over the CIR, which is causing numerous TCP retransmissions. The customer is not using any RTP applications but wants to maximize bandwidth usage up to the CIR. Which QoS solution should the engineer choose?

A. policing
B. queuing
C. traffic shaping
D. policer with markdown

Selected Answer: C

Question #: 139
Topic #: 1
The customer solution requires QoS to support streaming multimedia over a WAN. An architect chooses to use Per-Hop Behavior. Which solution should the engineer use to classify and mark traffic traveling between branch sites?

A. CBWFQ with DSCP AF2
B. LLQ with DSCP EF
C. CBWFQ with DSCP AF3
D. LLQ with DSCP AF4

Selected Answer: C

Question #: 140
Topic #: 1
An engineer must design an in-band management solution for a customer with branch sites. The solution must allow remote management of the branch sites using management protocols over an MPLS WAN. Queueing is implemented at the remote sites using these classes:
✑ Class1 equals voice traffic
✑ Class2 equals mission-critical traffic
✑ Class3 equals default traffic
How must the solution prioritize the management traffic over the WAN?

A. Mark the traffic with DSCP EF and map into Class1 with a minimum bandwidth assigned by reducing the bandwidth available to Class2.
B. Mark the traffic with DSCP CS1 and map into Class2 with a minimum bandwidth assigned by reducing the bandwidth available to Class3.
C. Mark the traffic with DSCP CS6 and map into Class1 with a minimum bandwidth assigned by reducing the bandwidth available to Class2.
D. Mark the traffic with DSCP CS2 and map into Class2 with a minimum bandwidth assigned by reducing the bandwidth available to Class3.

Selected Answer: D

Question #: 141
Topic #: 1
An engineer is designing a multicast network for a company specializing in VoD content. Receivers are across the Internet, and for performance reasons, the multicast framework must be close to the receivers within each AS. For high availability, if the sources in one AS are no longer available, the receivers of that AS must be able to receive the VoD content from the sources in another AS. Which feature must the design include?

A. SSM
B. anycast RP
C. bidirectional PIM
D. MSDP

Selected Answer: D

Question #: 142
Topic #: 1
An organization plans to deploy multicast across two different autonomous systems. Their solution must allow RPs to:
✑ discover active sources outside their domain
✑ use the underlying routing information for connectivity with other RPs
✑ announce sources joining the group
Which solution supports these requirements?

A. SSM
B. MSDP
C. PIM-DM
D. PIM-SM

Selected Answer: B

Question #: 143
Topic #: 1
Which type of rendezvous point deployment is standards-based and supports dynamic RP discovery?

A. bootstrap router
B. Anycast-RP
C. Auto-RP
D. static RP

Selected Answer: A

Question #: 144
Topic #: 1
An engineer must design a QoS solution for a customer. The network currently supports data only, but the customer will roll out VoIP and IP video in conjunction with the new QoS solution. The engineer plans to use DiffServ. To ensure priority for voice services, which model must the design include?

A. 8-class model
B. 4-class model
C. 6-class model
D. 12-class model

Selected Answer: A

Question #: 145
Topic #: 1
Which NETCONF operation creates filtering that is specific to the session notifications?

A.
B.
C.
D.

Selected Answer: A

Question #: 146
Topic #: 1
DRAG DROP –
Drag and drop the properties from the left onto the protocols they describe on the right.
Select and Place:

Suggestion Answer:

Question #: 147
Topic #: 1
DRAG DROP –
Drag and drop the characteristics from the left onto the telemetry mode they apply to on the right.
Select and Place:

Suggestion Answer:

Question #: 148
Topic #: 1
An engineer needs a standards-driven YANG model to manage a multivendor network environment. Which model should the engineer choose?

A. Native
B. OpenConfig
C. IETF
D. IEEE NETCONF

Selected Answer: B

Question #: 149
Topic #: 1
An engineer is working with NETCONF and Cisco NX-OS based devices. The engineer needs a YANG model that supports a specific feature relevant only to
Cisco NX-OS. Which model should the engineer choose?

A. Native
B. IEEE
C. OpenConfig
D. IETF

Selected Answer: A

Question #: 150
Topic #: 1
A client is moving to Model-Driven Telemetry and requires periodic updates. What must the network architect consider with this design?

A. Updates that contain changes within the data are sent only when changes occur.
B. Empty data subscriptions do not generate empty update notifications.
C. Periodic updates include a full copy of the data that is subscribed to.
D. The primary push update is sent immediately and cannot be delayed.

Selected Answer: C