CISCO CCNA Exam – Q283

A user is unable to connect to the Internet. Based on the layered approach to troubleshooting and beginning with the lowest layer, drag each procedure on the left to its proper category on the right.
CISCO CCNA Exam – Q283

Select and Place:
CISCO CCNA Exam – Q283b

Explanation:
The question asks us to “begin with the lowest layer” so we have to begin with Layer 1: verify physical connection; in this case an Ethernet cable connection. For your information, “verify Ethernet cable connection” means that we check if the type of connection (crossover, straight-through, rollover…) is correct, the RJ45 headers are plugged in, the signal on the cable is acceptable…

Next we “verify NIC operation”. We do this by simply making a ping to the loopback interface 127.0.0.1. If it works then the NIC card (layer 1, 2) and TCP/IP stack (layer 3) are working properly.

Verify IP configuration belongs to layer 3. For example, checking if the IP can be assignable for host, the PC’s IP is in the same network with the gateway…

Verifying the URL by typing in your browser some popular websites like google.com, microsoft.com to assure that the far end server is not down (it sometimes make we think we can’t access to the Internet). We are using a URL so this step belongs to layer 7 of the OSI model.

CISCO CCNA Exam – Q282

Refer to the exhibit.
CISCO CCNA Exam – Q282

A network administrator attempts to ping Host2 from Host1 and receives the results that are shown. What is the problem?

A. The link between Host1 and Switch1 is down.
B. TCP/IP is not functioning on Host1
C. The link between Router1 and Router2 is down.
D. The default gateway on Host1 is incorrect.
E. Interface Fa0/0 on Router1 is shutdown.
F. The link between Switch1 and Router1 is down.

Correct Answer: C

Explanation:
Host1 tries to communicate with Host2. The message destination host unreachable from Router1 indicates that the problem occurs when the data is forwarded from Host1 to Host2. According to the topology, we can infer that the link between Router1 and Router2 is down.

CISCO CCNA Exam – Q281

Refer to the exhibit.
CISCO CCNA Exam – Q281

Hosts in network 192.168.2.0 are unable to reach hosts in network 192.168.3.0. Based on the output from RouterA, what are two possible reasons for the failure? (Choose two.)

A. The cable that is connected to S0/0 on RouterA is faulty.
B. Interface S0/0 on RouterB is administratively down.
C. Interface S0/0 on RouterA is configured with an incorrect subnet mask.
D. The IP address that is configured on S0/0 of RouterB is not in the correct subnet.
E. Interface S0/0 on RouterA is not receiving a clock signal from the CSU/DSU.
F. The encapsulation that is configured on S0/0 of RouterB does not match the encapsulation that is configured on S0/0 of RouterA.

Correct Answers: E, F

Explanation:
From the output we can see that there is a problem with the Serial 0/0 interface. It is enabled, but the line protocol is down. There could be a result of mismatched encapsulation or the interface not receiving a clock signal from the CSU/DSU.

CISCO CCNA Exam – Q280

Refer to the exhibit.
CISCO CCNA Exam – Q280
An administrator pings the default gateway at 10.10.10.1 and sees the output as shown. At which OSI layer is the problem?

A. data link layer
B. application layer
C. access layer
D. session layer
E. network layer

Correct Answer: E

Explanation:
The command ping uses ICMP protocol, which is a network layer protocol used to propagate control message between host and router. The command ping is often used to
verify the network connectivity, so it works at the network layer.

CISCO CCNA Exam – Q279

Refer to the exhibit.
CISCO CCNA Exam – Q279

The two connected ports on the switch are not turning orange or green. What would be the most effective steps to troubleshoot this physical layer problem? (Choose three.)

A. Ensure that the Ethernet encapsulations match on the interconnected router and switch ports.
B. Ensure that cables A and B are straight-through cables.
C. Ensure cable A is plugged into a trunk port.
D. Ensure the switch has power.
E. Reboot all of the devices.
F. Reseat all cables.

Correct Answers: B, D, F

Explanation:
The ports on the switch are not up indicating it is a layer 1 (physical) problem so we should check cable type, power and how they are plugged in.

CISCO CCNA Exam – Q278

Refer to the exhibit.
CISCO CCNA Exam – Q278

The network shown in the diagram is experiencing connectivity problems. Which of the following will correct the problems? (Choose two.)

A. Configure the gateway on Host A as 10.1.1.1.
B. Configure the gateway on Host B as 10.1.2.254.
C. Configure the IP address of Host A as 10.1.2.2.
D. Configure the IP address of Host B as 10.1.2.2.
E. Configure the masks on both hosts to be 255.255.255.224.
F. Configure the masks on both hosts to be 255.255.255.240.

Correct Answers: B, D

Explanation:
The switch 1 is configured with two VLANs: VLAN1 and VLAN2.
The IP information of member Host A in VLAN1 is as follows:
Address : 10.1.1.126
Mask : 255.255.255.0
Gateway : 10.1.1.254
The IP information of member Host B in VLAN2 is as follows:
Address : 10.1.1.12
Mask : 255.255.255.0
Gateway : 10.1.1.254
The configuration of sub-interface on router 2 is as follows:
Fa0/0.1 — 10.1.1.254/24 VLAN1
Fa0/0.2 — 10.1.2.254/24 VLAN2
It is obvious that the configurations of the gateways of members in VLAN2 and the associated network segments are wrong. The layer3 addressing information of Host B should
be modified as follows:
Address : 10.1.2.X
Mask : 255.255.255.0

CISCO CCNA Exam – Q277

Refer to the exhibit.
CISCO CCNA Exam – Q277

A problem with network connectivity has been observed. It is suspected that the cable connected to switch port Fa0/9 on Switch1 is disconnected. What would be an effect of this cable being disconnected?

A. Host B would not be able to access the server in VLAN9 until the cable is reconnected.
B. Communication between VLAN3 and the other VLANs would be disabled.
C. The transfer of files from Host B to the server in VLAN9 would be significantly slower.
D. For less than a minute, Host B would not be able to access the server in VLAN9. Then normal network function would resume.

Correct Answer: D

Explanation:
Spanning-Tree Protocol (STP) is a Layer 2 protocol that utilizes a special-purpose algorithm to discover physical loops in a network and effect a logical loop-free topology. STP creates a loop-free tree structure consisting of leaves and branches that span the entire Layer 2 network. The actual mechanics of how bridges communicate and how the STP algorithm works will be discussed at length in the following topics. Note that the terms bridge and switch are used interchangeably when discussing STP. In addition, unless otherwise indicated, connections between switches are assumed to be trunks.

CISCO CCNA Exam – Q276

Refer to the exhibit.
CISCO CCNA Exam – Q276

HostA cannot ping HostB. Assuming routing is properly configured, what is the cause of this problem?

A. HostA is not on the same subnet as its default gateway.
B. The address of SwitchA is a subnet address.
C. The Fa0/0 interface on RouterA is on a subnet that can’t be used.
D. The serial interfaces of the routers are not on the same subnet.
E. The Fa0/0 interface on RouterB is using a broadcast address.

Correct Answer: D

Explanation:
Now let’s find out the range of the networks on serial link:
For the network 192.168.1.62/27:
Increment: 32
Network address: 192.168.1.32
Broadcast address: 192.168.1.63
For the network 192.168.1.65/27:
Increment: 32
Network address: 192.168.1.64
Broadcast address: 192.168.1.95
-> These two IP addresses don’t belong to the same network and they can’t see each other.

CISCO CCNA Exam – Q275

Which router IOS commands can be used to troubleshoot LAN connectivity problems? (Choose three.)

A. ping
B. tracert
C. ipconfig
D. show ip route
E. winipcfg
F. show interfaces

Correct Answers: A, D, F

Explanation:
Ping, show ip route, and show interfaces are all valid troubleshooting IOS commands. Tracert, ipconfig, and winipcfg are PC commands, not IOS.

CISCO CCNA Exam – Q274

A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common Ethernet link.
CISCO CCNA Exam – Q274

The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem?

A. The OSPF area is not configured properly.
B. The priority on R1 should be set higher.
C. The cost on R1 should be set higher.
D. The hello and dead timers are not configured properly.
E. A backup designated router needs to be added to the network.
F. The OSPF process ID numbers must match.

Correct Answer: D

Explanation:
In OSPF, the hello and dead intervals must match and here we can see the hello interval is set to 5 on R1 and 10 on R2. The dead interval is also set to 20 on R1 but it is 40 on R2.