2021 Apr 200-105 testing engine

Q21. - (Topic 2) 

Refer to the exhibit. 

The company uses EIGRP as the routing protocol. What path will packets take from a host on 192.168.10.192/26 network to a host on the LAN attached to router R1? 

R3# show ip route Gateway of last resort is not set 192 168.20.0/24 is variably subnetted, 6 subnets, 2 masks D 192.168.20.64/26 [90/2195456] via 192.168.20.9, 00:03:31, Serial0/0 D 192.168.20.0/30 [90/2681856] via 192.168.20.9, 00:03:31, Serial0/0 C 192.168.20.4/30 is directly connected, Serial0/1 C 192.168.20.8/30 is directly connected, Serial0/0 

C 192.168.20.192/26 is directly connected, FastEthernet0/0 

D 192.168.20.128/26 [90/2195456] via 192.168.20.5,00:03:31, Serial0/1 

A. The path of the packets will be R3 to R2 to R1 

B. The path of the packets will be R3 to R1 to R2 

C. The path of the packets will be both R3 to R2 to R1 and R3 to R1 

D. The path of the packets will be R3 to R1 

Answer:

Explanation: 

http://www.orbitco-ccna-pastquestions.com/CCNA---EIGRP-Common-Question.php 

Looking at the output display above, the LAN attached to router R1 belongs to 192.168.20.64/26 subnet and learned this network via 192.168.20.9 which will be an IP address in 192.168.20.8/30 sub-network. This means that packets destined for 

192.168.20.64 will be routed from R3 to R1. 


Q22. - (Topic 1) 

Which protocol provides a method of sharing VLAN configuration information between two Cisco switches? 

A. STP 

B. VTP 

C. 802.1Q 

D. RSTP 

Answer:

Explanation: 

Understanding VLAN Trunk Protocol (VTP) http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52. shtml 

Introduction VLAN Trunk Protocol (VTP) reduces administration in a switched network. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Catalyst series products. 


Q23. - (Topic 2) 

Refer to the exhibit. 

Assume that all router interfaces are operational and correctly configured. In addition, assume that OSPF has been correctly configured on router R2. How will the default route configured on R1 affect the operation of R2? 

A. Any packet destined for a network that is not directly connected to router R1 will be dropped. 

B. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately. 

C. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1. 

D. The networks directly connected to router R2 will not be able to communicate with the 172.16.100.0, 172.16.100.128, and 172.16.100.64 subnetworks. 

E. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur. 

Answer:

Explanation: 

First, notice that the more-specific routes will always be favored over less-specific routes regardless of the administrative distance set for a protocol. In this case, because we use OSPF for three networks (172.16.100.0 0.0.0.3, 172.16.100.64 0.0.0.63, 172.16.100.128 0.0.0.31) so the packets destined for these networks will not be affected by the default route. The default route configured on R1 "ip route 0.0.0.0 0.0.0.0 serial0/0 will send any packet whose destination network is not referenced in the routing table of router R1 to R2, it doesn't drop anything so answers A, B and C are not correct. D is not correct too because these routes are declared in R1 and the question says that "OSPF has been correctly configured on router R2, so network directly connected to router R2 can communicate with those three subnetworks. As said above, the default route configured on R1 will send any packet destined for a network that is not referenced in its routing table to 

R2; R2 in turn sends it to R1 because it is the only way and a routing loop will occur. 


Q24. - (Topic 1) 

What is one benefit of PVST+? 

A. PVST+ supports Layer 3 load balancing without loops. 

B. PVST+ reduces the CPU cycles for all the switches in the network. 

C. PVST+ allows the root switch location to be optimized per VLAN. 

D. PVST+ automatically selects the root bridge location, to provide optimized bandwidth usage. 

Answer:

Explanation: 

Per VLAN Spanning Tree (PVST) Introduction http://www.cisco.com/en/US/tech/tk389/tk621/tk846/tsd_technology_support_sub-protocol_home.html Per VLAN Spanning Tree (PVST) maintains a spanning tree instance for each VLAN configured in the network. This means a switch can be the root bridge of a VLAN while another switch can be the root bridge of other VLANs in a common topology. For example, Switch 1 can be the root bridge for Voice data while Switch 2 can be the root bridge for Video data. If designed correctly, it can optimize the network traffic. http://www.ciscopress.com/articles/article.asp?p=102157&seqNum=4 

Topic 2, Routing Technologies 


Q25. - (Topic 1) 

Refer to the exhibit. 

Why has this switch not been elected the root bridge for VLAN1? 

A. It has more than one interface that is connected to the root network segment. 

B. It is running RSTP while the elected root bridge is running 802.1d spanning tree. 

C. It has a higher MAC address than the elected root bridge. 

D. It has a higher bridge ID than the elected root bridge. 

Answer:

Explanation: 

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a008009482f.s html When a switch receives a BPDU, it first compares priority, the lower number wins. If a tie, compare MAC, the smaller one wins. Here Switch has 32769 priority which is greater than 20481 so switch will not elect for root bridge. It says the bridge priority for Switch is 32769, and the root priority is 20481. Which means that some other switch has the lower priority and won the election for VLAN 1. 


Q26. - (Topic 2) 

Refer to the exhibit. 

RTA is configured with a basic configuration. The link between the two routers is operational and no routing protocols are configured on either router. The line shown in the exhibit is then added to router RTA. Should interface Fa0/0 on router RTB shut down, what effect will the shutdown have on router RTA? 

A. A route to 172.16.14.0/24 will remain in the RTA routing table. 

B. A packet to host 172.16.14.225 will be dropped by router RTA. 

C. Router RTA will send an ICMP packet to attempt to verify the route. 

D. Because router RTB will send a poison reverse packet to router RTA, RTA will remove the route. 

Answer:

Explanation: 

Static routes remain in the routing table even if the specified gateway becomes unavailable. If the specified gateway becomes unavailable, you need to remove the static route from the routing table manually. However, static routes are removed from the routing table if the specified interface goes down, and are reinstated when the interface comes back up. Therefore the static route will only be removed from the routing table if the S0/0 interface on RTA is shutdown. 

Reference: http://www.cisco.com/en/US/docs/security/asa/asa84/configuration/guide/route_static.html) 


Q27. - (Topic 3) 

Refer to the exhibit. 

What is the meaning of the term dynamic as displayed in the output of the show frame-relay map command shown? 

A. The Serial0/0 interface is passing traffic. 

B. The DLCI 100 was dynamically allocated by the router 

C. The Serial0/0 interface acquired the IP address of 172.16.3.1 from a DHCP server 

D. The DLCI 100 will be dynamically changed as required to adapt to changes in the Frame Relay cloud 

E. The mapping between DLCI 100 and the end station IP address 172.16.3.1 was learned through Inverse ARP 

Answer:

Explanation: 

The term dynamic indicates that the DLCI number and the remote router IP address 

172.16.3.1 are learned via the Inverse ARP process. 

Inverse ARP is a technique by which dynamic mappings are constructed in a network, allowing a device such as a router to locate the logical network address and associate it with a permanent virtual circuit (PVC). 


Q28. - (Topic 3) 

Which two options are valid WAN connectivity methods? (Choose two.) 

A. PPP 

B. WAP 

C. DSL 

D. L2TPv3 

E. Ethernet 

Answer: A,C 

Explanation: 

On each WAN connection, data is encapsulated into frames before itcrosses the WAN link. The following are typical WAN protocols:1. High-level Data Link Control (HDLC): The Cisco default encapsulation type onpoint-to-point connections, dedicated links, and circuit-switches connections.2. PPP: Provides router-to-router and host-to-network connections over synchronous andasynchronous circuits. PPP was designed to work with several network layer protocols,including IP.3. Frame-relay: A successor to X.25. This protocol is an industry-standard, switchesdata-link layer protocol that handles multiple virtual circuits 

http://en.wikipedia.org/wiki/Wide_area_network 


Q29. - (Topic 3) 

The command frame-relay map ip 10.121.16.8 102 broadcast was entered on the router. Which of the following statements is true concerning this command? 

A. This command should be executed from the global configuration mode. 

B. The IP address 10.121.16.8 is the local router port used to forward data. 

C. 102 is the remote DLCI that will receive the information. 

D. This command is required for all Frame Relay configurations. 

E. The broadcast option allows packets, such as RIP updates, to be forwarded across the PVC. 

Answer:

Explanation: 

The command frame-relay map ip 10.121.16.8 102 broadcast means to map the remote IP 

10.121.16.8 to the local DLCI 102. When the “broadcast” keyword is included, it turns Frame Relay network as a broadcast network, which can forward broadcasts. 


Q30. - (Topic 1) 

Which three of these statements regarding 802.1Q trunking are correct? (Choose three.) 

A. 802.1Q native VLAN frames are untagged by default. 

B. 802.1Q trunking ports can also be secure ports. 

C. 802.1Q trunks can use 10 Mb/s Ethernet interfaces. 

D. 802.1Q trunks require full-duplex, point-to-point connectivity. 

E. 802.1Q trunks should have native VLANs that are the same at both ends. 

Answer: A,C,E 

Explanation: 

CCNA Self-Study (ICND Exam): Extending Switched Networks with Virtual LANs http://www.ciscopress.com/articles/article.asp?p=102157&seqNum=2