100-150 Practice Test 9 — 10 Questions

Question 1

Refer to the exhibit. What is the most likely cause of poor performance on this link?

Accepted Answer

The link is experiencing excessive congestion.. The exhibit shows an input rate of 1000 Mbps on an interface with a bandwidth of only 100 Mbps. This indicates massive oversubscription and congestion. The interface is attempting to process ten times the amount of data it is capable of handling, leading to packet drops, buffer exhaustion, and significant latency. This is a capacity issue rather than a physical error or protocol mismatch, requiring a bandwidth upgrade or traffic shaping.

Answer

The interface has a duplex mismatch.

Answer

The cable is faulty and causing retransmissions.

Answer

The interface MTU is configured incorrectly.

Question 2

Which characteristic best describes a softphone endpoint compared to a dedicated hardware-based IP phone?

Accepted Answer

Softphones are platform-independent applications running on general-purpose hardware.. Softphones are software applications residing on general-purpose computing devices, offering significant flexibility in deployment and updates. Because they share hardware resources like CPU and RAM with the OS, their performance is inherently dependent on the underlying system state. Understanding this distinction is vital for troubleshooting, as softphone issues often stem from local system resource contention rather than network-layer signaling or voice-specific hardware configuration errors.

Answer

Softphones require a dedicated physical Power over Ethernet switch port.

Answer

Softphones always offer superior voice quality due to hardware acceleration.

Answer

Softphones lack support for standard SIP signaling protocols.

Question 3

A technician is troubleshooting a PC that can communicate with other hosts on the same subnet but cannot reach any hosts on different subnets. Which configuration on the PC is most likely incorrect?

Accepted Answer

The default gateway address is incorrect.. The default gateway is the local router interface that allows a host to send traffic to remote networks. If a host can communicate locally, its IP and subnet mask are likely correct for the segment, but without a functional gateway, it has no path to send packets destined for any address outside its own subnet.

Answer

The DNS server address is missing.

Answer

The subnet mask is too restrictive.

Answer

The NIC is configured for the wrong duplex mode.

Question 4

A technician connects a new laptop to a Cisco Catalyst switch. The switch receives a frame destined for a MAC address that is not currently present in its MAC address table. What action will the switch take to ensure the frame reaches its intended destination?

Accepted Answer

The switch floods the frame out of all ports within the same VLAN, except for the port where the frame was received.. Switches use the MAC address table to make intelligent forwarding decisions. When a destination MAC address is missing from the table, the switch performs an unknown unicast flood. This mechanism ensures that the frame is delivered to the target device wherever it might be located within the broadcast domain. Understanding this fundamental behavior is critical for troubleshooting connectivity issues and analyzing traffic flow within a local area network environment.

Answer

The switch drops the frame immediately and sends an ICMP Destination Unreachable message to the source.

Answer

The switch forwards the frame to the default gateway to be resolved by a Layer 3 routing process.

Answer

The switch buffers the frame and generates an ARP request to determine the correct exit port for the destination MAC.

Question 5

Refer to the exhibit. A host connected to port FastEthernet0/2 is unable to communicate with other devices in VLAN 10. Based on the output, what can be concluded about port Fa0/2?

Accepted Answer

The host on Fa0/2 has not sent any traffic to the switch.. The MAC address table shows which devices are currently communicating through the switch. If a host is connected but its MAC address does not appear in the table, the switch has not received any valid frames from that device. This points to a failure in the initial communication process, likely at the physical or data link layer.

Answer

The switch has learned the MAC address but the port is blocked.

Answer

Port Fa0/2 is configured as a trunk port and is filtering traffic.

Answer

The host on Fa0/2 is using a static IP address.

Question 6

Refer to the exhibit. What is the effect of the 'ip dhcp snooping trust' command on the designated interface?

Accepted Answer

It permits DHCP server messages on the port.. In DHCP Snooping, ports are untrusted by default. The 'trust' command marks an interface as connected to a legitimate DHCP server, allowing DHCPOFFER and DHCPACK messages to pass through. Without this command, the switch would drop these server-originated messages on that port, preventing clients from receiving IP addresses. This is critical for controlling which DHCP servers are allowed to interact with the network, thereby mitigating unauthorized server attacks.

Answer

It forces the port to drop all DHCP traffic.

Answer

It enables port security on the interface.

Answer

It prevents ARP spoofing on the port.

Question 7

An organization wants to implement a security policy that requires users to authenticate against a centralized server before gaining network access. Which protocol provides the necessary AAA framework to achieve this?

Accepted Answer

RADIUS. The AAA framework (Authentication, Authorization, and Accounting) is the cornerstone of modern network security. Protocols like RADIUS and TACACS+ allow centralized management of user identity and access policies. By offloading authentication to a central server, administrators can ensure consistent security policies, audit trails for access, and rapid revocation of credentials, which is essential for scaling security across a complex enterprise network environment.

Answer

ICMP

Answer

DHCP

Answer

DNS

Question 8

A technician is troubleshooting a router that can ping its own interface but cannot ping a directly connected router's interface. The technician verifies that both interfaces are 'up/up'. What is the most likely cause?

Accepted Answer

The IP addresses are in different subnets.. When two routers are directly connected, they must share the same logical subnet to communicate. If the IP addresses are on different subnets or the subnet masks are mismatched, they will not be able to exchange packets. This is a common configuration error that occurs during initial setup or after a network change.

Answer

The routers are using different routing protocols.

Answer

The DNS server is not configured on the routers.

Answer

The 'no shutdown' command was not issued.

Question 9

Refer to the exhibit. Why is the interface fa0/1 currently in the 'Secure-shutdown' state?

Accepted Answer

The device connected has an unauthorized MAC address.. The interface is in 'Secure-shutdown' because a violation occurred. The port security configuration allowed for a maximum of one MAC address, and a device with a different MAC address than the one learned or configured attempted to connect. The violation mode was set to 'shutdown', which forces the port to disable itself to protect the network from the unauthorized device, requiring manual intervention to restore connectivity to the interface.

Answer

The port is configured for 'protect' mode.

Answer

The aging time has expired for the port.

Answer

The switch has lost power to the interface.

Question 10

Refer to the exhibit. An administrator is troubleshooting interface Gig0/1. The status is 'up/down'. What is the most likely reason for this state?

Accepted Answer

There is a Layer 2 encapsulation mismatch.. An 'up/down' status typically indicates a Layer 2 issue where the physical link is active but the data link layer is not negotiating correctly. Common causes include encapsulation mismatches, speed/duplex errors, or a failure in the keepalive mechanism. Identifying this specific state helps technicians isolate problems to the Layer 2 domain, preventing unnecessary troubleshooting of Layer 3 IP configurations.

Answer

The cable is disconnected.

Answer

The IP address is incorrectly configured.

Answer

The router is administratively shut down.