200-105 | All About Approved 200-105 practice test

New Questions 8

Which two statements about the OSPF Router ID are true? (Choose two.)

A. It identifies the source of a Type 1 LSA.

B. It should be the same on all routers in an OSPF routing instance.

C. By default, the lowest IP address on the router becomes the OSPF Router ID.

D. The router automatically chooses the IP address of a loopback as the OSPF Router ID.

E. It is created using the MAC Address of the loopback interface.

Answer: A,D

Explanation:

From the output of the u201cshow ip ospf databaseu201d:

New Questions 9

Routers R1 and R2 are on the same network segment, and both routers use interface Ethernet0/0. If R1 loses communication to R2, which two terns should you check as you begn GigabitEthernetO/0. If R1 lose: troubleshooting? (Choose two )

A. Verify that R2 is using 802 1q encapsulation

B. Verify that the GigabrtEthernet0/0 interfaces on R1 and R2 are configured with the same subnet mask.

C. Verify that the R1 GigabitEthernet0/0 interface is up and the line protocol is down.

D. Verify that R1 and R2 both are using HDLC encapsulation

E. that the R1 GigabitEthernet0/0 interface is up and the line protocol is up.

Answer: B,C

New Questions 10

If primary and secondary root switches with priority 16384 both experience catastrophic losses, which tertiary

switch can take over?

A. a switch with priority 20480

B. a switch with priority 8192

C. a switch with priority 4096

D. a switch with priority 12288

Answer: A

New Questions 11

Refer to the exhibit.

Which two statements are true about the loopback address that is configured on RouterB? (Choose two.)

A. It ensures that data will be forwarded by RouterB.

B. It provides stability for the OSPF process on RouterB.

C. It specifies that the router ID for RouterB should be 10.0.0.1.

D. It decreases the metric for routes that are advertised from RouterB.

E. It indicates that RouterB should be elected the DR for the LAN.

Answer: B,C

Explanation: A loopback interface never comes down even if the link is broken so it provides stability for the OSPF process (for example we use that loopback interface as the router-id) - B is correct.

The router-ID is chosen in the order below:

The highest IP address assigned to a loopback (logical) interface. If a loopback interface is not defined, the highest IP address of all active routeru2021s physical interfaces will be chosen.

-The loopback interface will be chosen as the router ID of RouterB - C is correct.

New Questions 12

Which statement about the router configurations is correct?

A. PPP PAP is authentication configured between Branch2 and R1.

B. Tunnel keepalives are not configured for the tunnel0 interface on Branch2 and R2.

C. The Branch2 LAN network 192.168.11 0/24 is not advertised into the EIGRP network.

D. The Branch3 LAW network 192.168.10.0/24 is not advertised into the EIGRP network.

E. PPP CHAP is authentication configured between Branch1 and R1.

Answer: D

Explanation:

When we check Branch3 router we notice that u201cnetwork 192.168.10.0u201d command is missing under u201crouter eigrp 100u201d making answer D correct.

New Questions 13

What OSPF command, when configured, will include all interfaces into area 0?

A. network 0.0.0.0 255.255.255.255 area 0

B. network 0.0.0.0 0.0.0.0 area 0

C. network 255.255.255.255 0.0.0.0 area 0

D. network all-interfaces area 0

Answer: A

Explanation:

Example 3-1 displays OSPF with a process ID of 1 and places all interfaces configured with an IP address in area 0. The network command network 0.0.0.0 255.255.255.255 area 0

dictates that you do not care (255.255.255.255) what the IP address is, but if an IP address is enabled on any interface, place it in area 0.

Example 3-1 Configuring OSPF in a Single Area

router ospf 1

network 0.0.0.0 255.255.255.255 area 0

Reference: http://www.ciscopress.com/articles/article.asp?p=26919&seqNum=3

Topic 4, WAN Technologies

127.What is the purpose of Inverse ARP?

A. to map a known IP address to a MAC address

B. to map a known DLCI to a MAC address

C. to map a known MAC address to an IP address

D. to map a known DLCI to an IP address

E. to map a known IP address to a SPID

F. to map a known SPID to a MAC address

Answer: D

Explanation:

http://www.ciscopress.com/articles/article.asp?p=170741&seqNum=4

Frame-Relay (a Layer 2 protocol) uses Inverse-Arp to map a know Layer 2 Address (DLCI) to a unknow Layer 3 Address.

Dynamic Mapping

Dynamic address mapping relies on the Frame Relay Inverse Address Resolution Protocol (Inverse ARP), defined by RFC 1293, to resolve a next hop network protocol address to a local DLCI value. The Frame Relay router sends out Inverse ARP requests on its Frame Relay PVC to discover the protocol address of the remote device connected to the Frame Relay network. The responses to the Inverse ARP requests are used to populate an address-to-DLCI mapping table on the Frame Relay router or access server. The router builds and maintains this address-to-DLCI mapping table, which contains all resolved Inverse ARP requests, including both dynamic and static mapping entries.

When data needs to be transmitted to a remote destination address, the router performs a lookup on its routing table to determine whether a route to that destination address exists and the next hop address or directly connected interface to use in order to reach that destination. Subsequently, the router consults its address-to-DLCI mapping table for the local DLCI that corresponds to the next hop address. Finally, the router places the frames targeted to the remote destination on its identified outgoing local DLCI.

On Cisco routers, dynamic Inverse ARP is enabled by default for all network layer protocols enabled on the physical interface. Packets are not sent out for network layer protocols that are not enabled on the physical interface. For example, no dynamic Inverse ARP resolution is performed for IPX if ipx routing is not enabled globally and there is no active IPX address assigned to the interface. Because dynamic Inverse ARP is enabled by default, no additional Cisco IOS command is required to enable it on an interface.

Example 4-16 shows the output of the show frame-relay map privileged EXEC mode command. The addressto-DLCI mapping table displays useful information. The output of the command shows that the next hop address 172.16.1.2 is dynamically mapped to the local DLCI 102, broadcast is enabled on the interface, and the interface's status is currently active.

NOTE

After enabling Frame Relay on the interface, the Cisco router does not perform Inverse ARP until IP routing is enabled on the router. By default, IP routing is enabled on a Cisco router. If IP routing has been turned off, enable IP routing with the ip routing command in the global configuration mode. After IP routing is enabled, the router performs Inverse ARP and begins populating the address-to-DLCI mapping table with resolved entries.

New Questions 14

Which statement is true, as relates to classful or classless routing?

A. Classful routing protocols send the subnet mask in routing updates.

B. RIPv1 and OSPF are classless routing protocols.

C. Automatic summarization at classful boundaries can cause problems on discontiguous subnets.

D. EIGRP and OSPF are classful routing protocols and summarize routes by default.

Answer: C

Explanation: http://www.ciscopress.com/articles/article.asp?p=174107&seqNum=3

RIPv1, RIPv2, IGRP, and EIGRP all auto-summarize classful boundaries by default (OSPF does not).To make discontiguous networks work, meaning you don't want classful boundries to summarize, you need to turn off auto-summary.

New Questions 15

Which port state is introduced by Rapid-PVST?

A. learning

B. listening

C. discarding

D. forwarding

Answer: C

Explanation:

Spanning Tree from PVST+ to Rapid-PVST Migration Configuration Example Reference 1:

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example 09186a00807b0670.shtml

Reference 2: http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cf a.shtml

PVST+ is based on IEEE802.1D Spanning Tree Protocol (STP). But PVST+ has only 3 port states (discarding, learning and forwarding) while STP has 5 port states (blocking, listening,

learning, forwarding and disabled). So discarding is a new port state in PVST+.

Background Information

802.1D Spanning Tree Protocol (STP) has a drawback of slow convergence. Cisco Catalyst switches support three types of STPs, which are PVST+, rapid-PVST+ and MST. PVST+ is based on IEEE802.1D standard and includes Cisco proprietary extensions such as BackboneFast, UplinkFast, and PortFast. Rapid-PVST+ is based on IEEE 802.1w standard and has a faster convergence than 802.1D. RSTP (IEEE 802.1w) natively includes most of the Cisco proprietary enhancements to the 802.1D Spanning Tree, such as BackboneFast and UplinkFast. Rapid-PVST+ has these unique features:

Uses Bridge Protocol Data Unit (BPDU) version 2 which is backward compatible with the 802.1D STP, which uses BPDU version 0.

All the switches generate BPDUs and send out on all the ports every 2 seconds, whereas in 802.1D STP only the root bridge sends the configuration BPDUs.

Port Rolesu2014Root port, designated port, alternate port and backup port. Port Statesu2014Discarding, Learning, and Forwarding.

Port Typesu2014Edge Port (PortFast), Point-to-Point and Shared port.

Rapid-PVST uses RSTP to provide faster convergence. When any RSTP port receives legacy 802.1D BPDU, it falls back to legacy STP and the inherent fast convergence benefits of 802.1w are lost when it interacts with legacy bridges.

New Questions 16

Which VLAN bridge priority value will make a switch as root for a given VLAN from the below options by the spanning-tree vlan vlan-id root command?

A. 16384

B. 8192

C. 28672

D. 32768

Answer: B

New Questions 17

Which two circumstances can cause collision domain issues on VLAN domain? (Choose two.)

A. duplex mismatches on Ethernet segments in the same VLAN

B. multiple errors on switchport interfaces

C. congestion on the switch inband path

D. a failing NIC in an end device

E. an overloaded shared segment

Answer: A,E

Explanation: Collision Domains

A collision domain is an area of a single LAN where end stations contend for access to the network because all end stations are connected to a shared physical medium. If two connected devices transmit onto the media at the same time, a collision occurs. When a collision occurs, a JAM signal is sent on the network, indicating that a collision has occurred and that devices should ignore any fragmented data associated with the collision. Both sending devices back off sending their data for a random amount and then try again if the medium is free for transmission. Therefore, collisions effectively delay transmission of data, lowering the effective throughput available to a device. The more devices that are attached to a collision domain, the greater the chances of collisions; this results in lower bandwidth and performance for each device attached to the collision domain. Bridges and switches terminate the physical signal path of a collision domain, allowing you to segment separate collision domains, breaking them up into multiple smaller pieces to provide more bandwidth per user within the new collision domains formed.