The Most up-to-date Guide To 400-101 practice exam Apr 2021


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Q151. Refer to the exhibit. 

Which two statements about this route table are true? (Choose two.) 

A. The BGP routes are internal. 

B. The OSPF routes with the E2 flag retain the same metric as they leave the router. 

C. The OSPF routes with the IA flag have their administrative distances incremented as they leave the router. 

D. The BGP routes are external. 

E. The OSPF routes with the E2 flag have their metrics incremented as they leave the router. 

Answer: A,B 

Explanation: 

IBGP routes have an Administrative distance of 200, while EBGP have an AD of 20. Here we see that the BGP routes have an AD value of 200. 

With OSPF, external routes fall under two categories, external type 1 and external type 2. 

The difference between the two is in the way the cost (metric) of the route is being calculated. The cost of a type 2 route is always the external cost, irrespective of the interior cost to reach that route. A type 1 cost is the addition of the external cost and the internal cost used to reach that route. The metric for E2 routes do not change when advertising to other routers. 


Q152. Which statement describes the purpose of the Payload Type field in the RTP header? 

A. It identifies the signaling protocol. 

B. It identifies the codec. 

C. It identifies the port numbers for RTP. 

D. It identifies the port numbers for RTCP. 

Answer:

Explanation: 

PT, Payload Type. 7 bits: Identifies the format of the RTP payload and determines its interpretation by the application. A profile specifies a default static mapping of payload type codes to payload formats. Additional payload type codes may be defined dynamically through non-RTP means. An RTP sender emits a single RTP payload type at any given time; this field is not intended for multiplexing separate media streams. A full list of codecs and their payload type values can be found at the link below: 

Reference: http://www.networksorcery.com/enp/protocol/rtp.htm 


Q153. What is the destination MAC address of a BPDU frame? 

A. 01-80-C2-00-00-00 

B. 01-00-5E-00-00-00 

C. FF-FF-FF-FF-FF-FF 

D. 01-80-C6-00-00-01 

Answer:

Explanation: 

The root-bridge election process begins by having every switch in the domain believe it is the root and claiming it throughout the network by means of Bridge Protocol Data Units (BPDU). BPDUs are Layer 2 frames multicast to a well-known MAC address in case of IEEE STP (01-80-C2-00-00-00) or vendor-assigned addresses, in other cases. 

Reference: http://www.ciscopress.com/articles/article.asp?p=1016582 


Q154. Refer to the exhibit. 

What is wrong with the configuration of the tunnel interface of this DMVPN Phase II spoke router? 

A. The interface MTU is too high. 

B. The tunnel destination is missing. 

C. The NHRP NHS IP address is wrong. 

D. The tunnel mode is wrong. 

Answer:

Explanation: 

By default, tunnel interfaces use GRE as the tunnel mode, but a DMVPN router needs to be configured for GRE multipoint by using the “tunnel mode gre multipoint” interface command. 


Q155. Refer to the exhibit. 

You discover that only 1.5 Mb/s of web traffic can pass during times of congestion on the given network. 

Which two options are possible reasons for this limitation? (Choose two.) 

A. The web traffic class has too little bandwidth reservation. 

B. Video traffic is using too much bandwidth. 

C. The service-policy is on the wrong interface. 

D. The service-policy is going in the wrong direction. 

E. The NAT policy is adding too much overhead. 

Answer: A,B 

Explanation: 

In this example, the web traffic will fall into the default class, which is only 15 percent of the 10Mbps Internet connection (1.5Mbps). Meanwhile, video traffic is allowed 50% of the 10 Mbps. 


Q156. Which two OSPF network types require the use of a DR and BDR? (Choose two.) 

A. non-broadcast networks 

B. point-to-point networks 

C. point-to-multipoint networks 

D. broadcast networks 

E. point-to-multipoint non-broadcast networks 

Answer: A,D 


Q157. Which three options are characteristics of a Type 10 LSA? (Choose three.) 

A. It is an area-local, opaque LSA. 

B. Data is flooded to all routers in the LSA scope. 

C. It is used for traffic-engineering extensions to OSPF. 

D. It is a link-local, opaque LSA. 

E. Data is flooded only to the routers in the LSA scope that understand the data. 

F. It is used for traffic-engineering extensions to LDP. 

Answer: A,B,C 


Q158. What is a reason for an EIGRP router to send an SIA reply to a peer? 

A. to respond to an SIA query with the alternative path requested 

B. to respond to a query reporting that the prefix has gone stuck-in-active 

C. to respond to an SIA query that the router is still waiting on replies from its peers 

D. to respond to a reply reporting that the prefix has gone stuck-in-active 

Answer:


Q159. Which protocol will accept incoming updates when the passive-interface command is configured? 

A. OSPF 

B. IS-IS 

C. RIP 

D. EIGRP 

Answer:


Q160. Which two statements about NetFlow are true? (Choose two.) 

A. It must be configured on each router in a network. 

B. It supports ATM LAN emulation. 

C. The existing network is unaware that NetFlow is running. 

D. It uses SIP to establish sessions between neighbors. 

E. It provides resource utilization accounting. 

Answer: C,E 

Explanation: 

NetFlow identifies packet flows for both ingress and egress IP packets. It does not involve any connection-setup protocol, either between routers or to any other networking device or end station. NetFlow does not require any change externally--either to the packets themselves or to any networking device. NetFlow is completely transparent to the existing network, including end stations and application software and network devices like LAN switches. Also, NetFlow capture and export are performed independently on each internetworking device; NetFlow need not be operational on each router in the network. NetFlow data provides fine-grained metering for highly flexible and detailed resource utilization accounting. For example, flow data includes details such as IP addresses, packet and byte counts, timestamps, type-of-service, and application ports. Service providers might utilize the information for billing based on time-of-day, bandwidth usage, application usage, or quality of service. Enterprise customers might utilize the information for departmental chargeback or cost allocation for resource utilization. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/netflow/configuration/12-4t/nf-12-4t-book/ios-netflow-ov.html