100-105 | The Secret of Cisco 100-105 exam question

Question No: 5

Refer to the exhibit.

What kind of cable should be used to make each connection that is identified by the numbers shown?

A. 1 - Ethernet Crossover cable

2 - Ethernet straight-through cable

3 - Fiber Optic cable

4 - Rollover cable

B. 1 - Ethernet straight-through cable

2 - Ethernet straight-through cable

3 - Serial cable

4 - Rollover cable

C. 1 - Ethernet rollover cable

2 - Ethernet crossover cable

3 - Serial cable

4 - Null-modem cable

D. 1 - Ethernet straight-through cable

2 - Ethernet Crossover cable

3 - Serial cable

4 - Rollover cable

E. 1 - Ethernet straight-through cable

2 - Ethernet Crossover cable

3 - Serial cable

4 - Ethernet Straight-through cable

Answer: B

Explanation:

When connecting a PC to a switch, a standard Ethernet straight through cable should be used. This same cable should also be used for switch to router connections. Generally speaking, crossover cables are only needed when connecting two like devices (PC-PC, switch-switch, router-router, etc).

Routers connect to frame relay and other WAN networks using serial cables. Rollover cables are special cables used for connecting to the console ports of Cisco devices.

Question No: 6

Refer to the exhibit.

If the hubs in the graphic were replaced by switches, what would be virtually eliminated?

A. broadcast domains

B. repeater domains

C. Ethernet collisions

D. signal amplification

E. Ethernet broadcasts

Answer: C

Explanation:

Modern wired networks use a network switch to eliminate collisions. By connecting each device directly to a port on the switch, either each port on a switch becomes its own collision domain (in the case of half duplex links) or the possibility of collisions is eliminated entirely in the case of full duplex links.

Question No: 7

What information can be used by a router running a link-state protocol to build and maintain its topological database? (Choose two.)

A. hello packets

B. SAP messages sent by other routers

C. LSAs from other routers

D. beacons received on point-to-point links

E. routing tables received from other link-state routers

F. TTL packets from designated routers

Answer: A,C

Explanation: Reference 1:

http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=4

Link state protocols, sometimes called shortest path first or distributed database protocols, are built around a well-known algorithm from graph theory, E. W. Dijkstra'a shortest path algorithm. Examples of link state routing protocols are:

Open Shortest Path First (OSPF) for IP

The ISO's Intermediate System to Intermediate System (IS-IS) for CLNS and IP DEC's DNA Phase V

Novell's NetWare Link Services Protocol (NLSP)

Although link state protocols are rightly considered more complex than distance vector protocols, the basic functionality is not complex at all:

1. Each router establishes a relationshipu2014an adjacencyu2014with each of its neighbors.

2. Each router sends link state advertisements (LSAs), some

3. Each router stores a copy of all the LSAs it has seen in a database. If all works well, the databases in all routers should be identical.

4. The completed topological database, also called the link state database, describes a graph of the internetwork. Using the Dijkstra algorithm, each router calculates the shortest path to each network and enters this information into the route table.

OSPF Tutorial

Question No: 8

To allow or prevent load balancing to network 172.16.3.0/24, which of the following commands could be used in R2? (Choose two.)

A. R2(config-if)#clock rate

B. R2(config-if)#bandwidth

C. R2(config-if)#ip ospf cost

D. R2(config-if)#ip ospf priority

E. R2(config-router)#distance ospf

Answer: B,C

Explanation:

http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.sht ml#t6

The cost (also called metric) of an interface in OSPF is an indication of the overhead required to send packets across a certain interface. The cost of an interface is inversely proportional to the bandwidth of that interface. A higher bandwidth indicates a lower cost. There is more overhead (higher cost) and time delays involved in crossing a 56k serial line than crossing a 10M Ethernet line. The formula used to calculate the cost is:

Cost = 10000 0000/bandwidth in bps

For example, it will cost 10 EXP8/10 EXP7 = 10 to cross a 10M Ethernet line and will cost 10 EXP8/1544000 =64 to cross a T1 line.

By default, the cost of an interface is calculated based on the bandwidth; you can force the cost of an interface with the ip ospf cost <value> interface subconfiguration mode command.

Question No: 9

Two routers named Atlanta and Brevard are connected by their serial interfaces as shown in the exhibit, but there is no data connectivity between them. The Atlanta router is known to have a correct configuration.

Given the partial configurations shown in the exhibit, what is the problem on the Brevard router that is causing the lack of connectivity?

A. A loopback is not set.

B. The IP address is incorrect.

C. The subnet mask is incorrect.

D. The serial line encapsulations are incompatible.

E. The maximum transmission unit (MTU) size is too large.

F. The bandwidth setting is incompatible with the connected interface.

Answer: B

Explanation:

The connection between two routers must have IP addresses that belong to the same subnet, but in this case Atlanta is using 192.168.10.1/24 and the other is in 192.168.11.1/24.

Question No: 10

Refer to the exhibit.

Given the output for this command, if the router ID has not been manually set, what router ID will OSPF use for this router?

A. 10.1.1.2

B. 10.154.154.1

C. 172.16.5.1

D. 192.168.5.3

Answer: C

Explanation:

The highest IP address of all loopback interfaces will be chosen -> Loopback 0 will be chosen as the router ID.

Question No: 11

Which two commands will display the current IP address and basic Layer 1 and 2 status of an interface? (Choose two.)

A. router#show version

B. router#show ip interface

C. router#show protocols

D. router#show controllers

E. router#show running-config

Answer: B,C

Explanation:

The outputs of u201cshow protocolsu201d and u201cshow ip interfaceu201d are shown below:

Global values:Internet Protocol routing is enabledSerial0/0 is up, line protocol is downInternet address is 10.1.1.1/30Serial0/1 is up, line protocol is downInternet address is 209.65.200.225/30Serial0/2 is up, line protocol is downSerial0/3 is up, line protocol is downNVI0 is up, line protocol is upInterface is unnumbered. Using address of NVI0 (0.0.0.0)Loopback0 is up, line protocol is upInternet address is 10.1.10.1/32Loopback1 is up, line protocol is upInternet address is 10.1.2.1/27Loopback6 is up, line protocol is up

Serial0/0 is up, line protocol is downInternet address is 10.1.1.1/30Broadcast address is 255.255.255.255Address determined by non-volatile memoryMTU is 1500 bytesHelper address is not setDirected broadcast forwarding is disabledMulticast reserved groups joined: 224.0.0.5Outgoing access list is not setInbound access list is not setProxy ARP is enabledLocal Proxy ARP is disabledSecurity level is defaultSplit horizon is disabledICMP redirects are always sentICMP unreachables are always sentICMP mask replies are never sentIP fast switching is enabledIP fast switching on the same interface is enabledIP Flow switching is disabledIP CEF switching is disabledIP Feature Fast switching turbo vectorIP multicast fast switching is enabledIP multicast distributed fast switching is disabledIP route- cache flags are FastRouter Discovery is disabledIP output packet accounting is disabledIP access violation accounting is disabledTCP/IP header compression is disabledRTP/IP header compression is disabledPolicy routing is disabledNetwork address translation is enabled, interface in domain insideBGP Policy Mapping is disabledWCCP Redirect outbound is disabledWCCP Redirect inbound is disabledWCCP Redirect exclude is disabled

Question No: 12

Which IP address is a private address?

A. 12.0.0.1

B. 168.172.19.39

C. 172.20.14.36

D. 172.33.194.30

E. 192.169.42.34

Answer: C

Question No: 13

Why do large OSPF networks use a hierarchical design? (Choose three.)

A. to decrease latency by increasing bandwidth

B. to reduce routing overhead

C. to speed up convergence

D. to confine network instability to single areas of the network

E. to reduce the complexity of router configuration

F. to lower costs by replacing routers with distribution layer switches

Answer: B,C,D

Explanation:

OSPF implements a two-tier hierarchical routing model that uses a core or backbone tier known as area zero (0). Attached to that backbone via area border routers (ABRs) are a number of secondary tier areas.

The hierarchical approach is used to achieve the following:

u2711 Rapid convergence because of link and/or switch failures

u2711 Deterministic traffic recovery

u2711 Scalable and manageable routing hierarchy, reduced routing overhead.

Question No: 14

What is the OSPF default frequency, in seconds, at which a Cisco router sends hello packets on a multi-access network?

A. 10

B. 40

C. 30

D. 20

Answer: A

Explanation:

On broadcast multiacess and point-to-point links, the default is 10 seconds. On NBMA, the default is 30 seconds.