Examkin

All practice questions

1987 questions

All types1,987Multiple choice1,020Multiple select452Numeric18Matching229Ordering203Fill in the blank22Short answer43
Question 1041Question →

A network administrator is deploying non-Cisco VoIP IP phones connected to a Cisco Catalyst switch. While Cisco Discovery Protocol (CDP) is enabled by default, the non-Cisco devices require Link Layer Discovery Protocol (LLDP) to receive VLAN assignments and power settings. Which command must the administrator execute in global configuration mode to enable LLDP globally across the switch?

Show answer & explanation

Answer: lldp run

Answer

The command `lldp run` entered in global configuration mode enables LLDP globally across the Cisco switch.
The command `lldp run` is executed in global configuration mode to start the LLDP service switch-wide on Cisco devices. Once enabled globally, individual interfaces will transmit and receive LLDP advertisements.

Step-by-Step Solution

1
Identify the protocol requirement
LLDP (IEEE 802.1AB) is required for interoperability with non-Cisco devices.
CDP is Cisco-proprietary, whereas LLDP is an open standard supported across multi-vendor equipment.
2
Determine the global CLI configuration syntax for LLDP
The command to enable LLDP globally on Cisco IOS is `lldp run`.
In Cisco IOS/IOS-XE, global protocol enablement for LLDP follows the syntax `lldp run` (similar to `ip routing` or `cdp run`).

Key Concept

Global activation of LLDP on Cisco Catalyst switches
Estimated Time:45s
Question 1042Question →

An engineer executes the `show spanning-tree interface gigabitethernet 1/0/10` command on a Cisco switch after connecting a desktop PC. The output displays the port in the STP Learning state. What is the operational behavior of interface GigabitEthernet 1/0/10 while in this port state?

Show answer & explanation

Answer: The interface populates the MAC address table from incoming frames but does not forward user data traffic.

Answer

The interface populates the MAC address table from incoming frames but does not forward user data traffic.
In classic IEEE 802.1D Spanning Tree Protocol, the Learning state allows the switch port to learn source MAC addresses from frames received on the port and populate the switch MAC address table. However, to prevent Layer 2 loops while topology information stabilizes, the port does not yet forward user data frames or relay frames between interfaces.

Step-by-Step Solution

1
Analyze standard 802.1D Spanning Tree Protocol port states in chronological sequence.
The progression order is Blocking → Listening → Learning → Forwarding.
Understanding the function of each state ensures correct identification of port behavior.
2
Examine the specific actions permitted during the Learning state.
The port receives and sends BPDUs, and reads incoming frames to populate the MAC address table, but user traffic forwarding remains disabled.
Learning MAC addresses before entering the Forwarding state reduces initial unicast flooding once forwarding begins.

Key Concept

802.1D STP Port State Operational Characteristics
Estimated Time:1m 15s
Question 1043Question →

A network administrator needs to configure a routed (Layer 3) EtherChannel using LACP dynamic negotiation across physical interfaces GigabitEthernet0/1 and GigabitEthernet0/2 on a Cisco switch. Place the configuration steps in the correct sequential order from first to last.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence of steps to configure a Layer 3 EtherChannel using LACP is: 1) Enter interface range configuration mode for the physical member interfaces; 2) Execute the 'no switchport' command on the physical member interfaces; 3) Execute the 'channel-group 1 mode active' command on the physical member interfaces; 4) Enter logical interface Port-channel 1 configuration mode and assign the IPv4 address and subnet mask.
The proper administrative workflow begins by selecting physical member links GigabitEthernet0/1 and GigabitEthernet0/2. Disabling Layer 2 switching on these interfaces via 'no switchport' establishes them as routed interfaces. Binding them to channel-group 1 using LACP active mode creates the logical port-channel and begins dynamic trunk negotiation. Finally, navigating into interface Port-channel 1 mode permits configuration of the routed IP address.

Step-by-Step Solution

1
Select physical member links
Switch prompt changes to (config-if-range).
Allows configuration changes to be applied simultaneously across both physical interfaces.
2
Disable Layer 2 switchport mode on physical interfaces
'no switchport' command converts physical member links into routed ports.
Layer 3 EtherChannels require member interfaces to operate as routed ports rather than Layer 2 switchports.
3
Enable LACP active mode on physical interfaces
'channel-group 1 mode active' dynamically creates logical interface Port-channel 1.
Active mode ensures the switch actively initiates LACP negotiation across the member links.
4
Assign IP address to the logical port-channel
IPv4 address and subnet mask are configured on interface Port-channel 1.
For Layer 3 EtherChannels, IP routing occurs on the aggregate logical interface.

Key Concept

Layer 3 EtherChannel LACP Configuration Sequence
Estimated Time:1m 0s
Question 1044Question →

Match each Ethernet physical interface transceiver standard to its corresponding physical cabling medium, optical wavelength, and maximum distance specification.

Click a left item, then click its matching right item

Items

10GBASE-SR
1000BASE-LX
1000BASE-T
10GBASE-LR

Matches

Show answer & explanation

Answer

10GBASE-SR matches 850 nm OM3 MMF up to 300 m; 1000BASE-LX matches 1310 nm SMF up to 5 km; 1000BASE-T matches 4-pair Cat 5e/6 UTP up to 100 m; 10GBASE-LR matches 1310 nm SMF up to 10 km.
Each physical interface type is uniquely defined by its transmission speed (1G vs 10G), medium (Copper UTP, MMF, or SMF), optical wavelength (850 nm vs 1310 nm), and distance limit (100 m, 300 m, 5 km, 10 km). Matching these characteristics correctly ensures physical layer compatibility and prevents signal degradation over specified link lengths.

Step-by-Step Solution

1
Identify the transmission speed and medium type for each standard.
Standards starting with '1000BASE' denote 1 Gbps, while '10GBASE' standards denote 10 Gbps. 'T' indicates twisted-pair copper, 'SR' indicates short-range multimode fiber, and 'LX'/'LR' denote long-reach single-mode fiber.
Ethernet standard nomenclature directly describes operational speed and physical media characteristics.
2
Map optical wavelength and maximum distance limits to each optic spec.
Short-range multimode optics (SR) utilize 850 nm VCSEL lasers (300 m reach on OM3). Long-range single-mode optics (LX/LR) utilize 1310 nm lasers (5 km for 1G LX, 10 km for 10G LR). Copper Gigabit (1000BASE-T) uses RJ-45 over Cat5e/6 for 100 m.
Wavelength and fiber core design (SMF vs MMF) dictate distance limitations due to modal dispersion and attenuation.

Key Concept

Physical interface transceiver optics and copper cabling distance/speed standards
Question 1045Question →

An administrator is troubleshooting an interswitch link between SwitchA and SwitchB. Interface GigabitEthernet0/2 on SwitchA is configured with 'switchport mode dynamic desirable'. Interface GigabitEthernet0/2 on SwitchB is configured with 'switchport mode dynamic auto'. Trunking is successfully established, but the console displays periodic '%CDP-4-NATIVE_VLAN_MISMATCH' warning messages. What is the root cause of this error message?

Show answer & explanation

Answer: The two connected switch interfaces are configured with different native VLAN IDs.

Answer

The two connected switch interfaces are configured with different native VLAN IDs.
Cisco Discovery Protocol (CDP) periodically sends Layer 2 messages containing native VLAN information across switch links. When an 802.1Q trunk link is established between two switches, both sides must agree on the native VLAN ID. If one switch port is configured with native VLAN 1 and the other with native VLAN 99, CDP detects the mismatch and emits the %CDP-4-NATIVE_VLAN_MISMATCH console alert.

Step-by-Step Solution

1
Analyze DTP negotiation status between dynamic desirable and dynamic auto.
Dynamic desirable actively initiates DTP negotiation while dynamic auto responds, resulting in a successfully established 802.1Q trunk link.
Understanding DTP mode matrix confirms trunk operational status.
2
Analyze the syslog error message %CDP-4-NATIVE_VLAN_MISMATCH.
Cisco Discovery Protocol (CDP) exchanges Native VLAN Type-Length-Value (TLV) fields between neighboring switches across the trunk link.
When the native VLAN configured on one end of an 802.1Q trunk does not match the native VLAN on the opposing end, CDP triggers this specific warning log.

Key Concept

802.1Q Native VLAN Inconsistency and CDP Detection
Estimated Time:1m 15s
Question 1046Question →

An administrator is inspecting SLAAC autoconfiguration logs on a host workstation connected to an enterprise switch port. The host has dynamically derived the link-local IPv6 address fe80::a8bb:ccff:fe11:2233fe80::a8bb:ccff:fe11:2233 using the standard IEEE EUI-64 process. Which 48-bit MAC address belongs to the physical network interface card of this host?

Show answer & explanation

Answer: aabb.cc11.2233

Answer

The physical MAC address of the host network interface is aabb.cc11.2233.
The MAC address aabb.cc11.2233 is correct because reversing the EUI-64 process involves removing the inserted midpoint sequence FFFE and toggling the 7th bit (Universal/Local bit) of the first byte. The first byte of the interface ID is hex A8 (binary 1010 1000). Toggling the 7th bit (the second least-significant bit of the byte) changes it to binary 1010 1010, which corresponds to hex AA. Combining AA with the remaining bytes after removing FFFE yields aabb.cc11.2233.

Step-by-Step Solution

1
Extract the 64-bit Interface Identifier from the link-local address.
Interface Identifier is a8bb:ccff:fe11:2233a8bb:ccff:fe11:2233.
The prefix fe80::/64fe80::/64 forms the network portion, while the last 64 bits represent the EUI-64 interface ID.
2
Remove the 16-bit ff:feff:fe sequence inserted into the midpoint of the EUI-64 address.
Splitting at ff:feff:fe yields a8:bb:cca8:bb:cc and 11:22:3311:22:33, forming a8bb.cc11.2233a8bb.cc11.2233.
During EUI-64 generation, 0xfffe0xfffe (1616 bits) is inserted between the OUI (first 24 bits) and the NIC-assigned portion (last 24 bits).
3
Invert the 7th bit (Universal/Local bit) of the first MAC octet.
First octet a8a8 (1010 100021010\ 1000_2) with 7th bit inverted becomes aaaa (1010 101021010\ 1010_2). Combining all octets gives aabb.cc11.2233aabb.cc11.2233.
EUI-64 creation toggles the 7th bit (U/L bit) of the first MAC byte. Reversing the operation requires toggling bit 7 back to its original state.

Key Concept

Deriving original MAC address from IPv6 EUI-64 interface identifier by removing FFFE midpoint insertion and toggling the Universal/Local (7th) bit.
Estimated Time:2m 0s
Question 1047Question →

To reduce network join latency for desktop computers during operating system startup, a Cisco switch interface connected to an end-user host is configured with PortFast. Which specific operational behavior does PortFast introduce on this interface?

Show answer & explanation

Answer: The interface bypasses the Listening and Learning states to transition directly from Blocking to Forwarding upon link initialization.

Answer

The interface bypasses the Listening and Learning states to transition directly from Blocking to Forwarding upon link initialization.
Enabling PortFast on an access port allows the switch interface to transition immediately into the Forwarding state upon detecting link status up, bypassing the normal Listening (15 seconds) and Learning (15 seconds) STP states. This eliminates initialization delays for end hosts such as workstations and servers.

Step-by-Step Solution

1
Identify standard 802.1D STP port state transition timers for access ports.
Standard 802.1D STP transitions through Blocking -> Listening (15s) -> Learning (15s) -> Forwarding, totaling 30 seconds of convergence delay.
During Listening and Learning states, user data frames are dropped while the switch listens for BPDUs and populates its MAC address table.
2
Analyze the functional impact of enabling Cisco STP PortFast on an access interface.
PortFast causes the interface to skip the 15-second Listening and 15-second Learning delay, moving immediately into the Forwarding state when the physical link comes up.
End-user workstations do not create Layer 2 loops, so delaying data forwarding for 30 seconds is unnecessary and causes application initialization timeouts.

Key Concept

STP PortFast operational mechanics and state bypass
Question 1048Question →

Which Cisco Wireless LAN Controller (WLC) interface is dedicated exclusively to out-of-band management and operates on an isolated physical port separate from wireless client data traffic?

Show answer & explanation

Answer: Service port

Answer

The Service port is dedicated exclusively to out-of-band management.
The Service port is a dedicated physical port on a Cisco WLC used strictly for out-of-band management. It remains completely isolated from the controller's distribution system ports, CAPWAP tunnel termination, and wireless client data traffic.

Step-by-Step Solution

1
Identify the requirement for out-of-band management isolation on a Cisco Wireless LAN Controller.
Out-of-band management requires a dedicated physical interface isolated from client data traffic and CAPWAP tunnels.
This separation allows administrators to reach the controller even if in-band network interfaces or distribution trunks experience failures.
2
Evaluate the functionality of the WLC Service port.
The Service port is a dedicated physical port used exclusively for out-of-band system administration via protocols such as HTTPS and SSH.
Unlike in-band interfaces, the Service port does not carry CAPWAP tunnel traffic or wireless user data traffic.

Key Concept

Cisco WLC Service Port for Out-of-Band Management Access
Question 1049Question →

Match each network virtualization component or abstraction on the left with its corresponding operational role in an enterprise host environment on the right.

Click a left item, then click its matching right item

Items

Virtual Network Interface Card (vNIC)
Physical Network Interface Card (pNIC)
Virtual Switch (vSwitch)
Type 1 Hypervisor

Matches

Show answer & explanation

Answer

Virtual Network Interface Card (vNIC) matches with the virtual network adapter presented to a guest OS; Physical Network Interface Card (pNIC) matches with the physical hardware adapter connecting to external switches; Virtual Switch (vSwitch) matches with the software-based switching entity in host memory; Type 1 Hypervisor matches with the bare-metal software layer operating directly on server hardware.
Each virtualization element is accurately mapped to its functional role: vNIC provides virtual adapter presentation to guest VMs, pNIC acts as physical network uplink hardware, vSwitch performs host memory frame switching, and Type 1 hypervisor executes directly on bare-metal hardware.

Step-by-Step Solution

1
Analyze guest network adapter abstractions.
Identify that a vNIC is software exposed to the virtual machine operating system to provide virtual MAC and network connectivity.
Virtual machines require software-emulated interface cards to send and receive frames.
2
Analyze host hardware uplinks.
Associate pNIC with the physical host server hardware interface card.
The pNIC serves as the physical bridge carrying vSwitch traffic onto the physical infrastructure.
3
Evaluate internal frame forwarding constructs.
Match Virtual Switch (vSwitch) to software-based switching inside hypervisor memory.
vSwitches manage Layer 2 forwarding between VM interfaces and physical uplink ports within the hypervisor.
4
Determine hypervisor architecture classification.
Match Type 1 Hypervisor to bare-metal execution operating directly on server hardware.
Type 1 hypervisors control host hardware directly rather than running on top of an OS.

Key Concept

Virtualization Fundamentals and Host Components
Question 1050Question →

During a network audit, a network engineer discovers that `spanning-tree portfast default` is enabled globally on an access switch. A junior technician subsequently connects an unmanaged switch to one of the access ports. Assuming BPDU Guard is NOT configured on the port, what occurs when the Cisco switch interface receives a Spanning Tree Protocol (STP) BPDU from the unmanaged switch?

Show answer & explanation

Answer: The interface immediately loses its PortFast operational status, transitions to the Blocking state, and moves through standard IEEE 802.1D port states.

Answer

The interface immediately loses its PortFast operational status, transitions to the Blocking state, and moves through standard IEEE 802.1D port states.
Cisco PortFast allows end-user host ports to bypass the 30-second STP listening and learning delays and enter the forwarding state immediately. However, PortFast does not disable BPDU processing. If a PortFast-enabled interface receives an STP BPDU (indicating a switch or hub is attached), the interface loses its PortFast status and reverts to standard 802.1D STP operation, transitioning to the Blocking state to safely evaluate network topology and prevent bridging loops.

Step-by-Step Solution

1
Analyze PortFast behavior upon receiving BPDUs without BPDU Guard
PortFast allows an access port to immediately move from Blocking to Forwarding, skipping Listening and Learning states. However, it does not stop the port from sending or receiving BPDUs.
PortFast is designed strictly for edge ports connected to single end-user devices.
2
Evaluate the interface state transition when a BPDU arrives
When a BPDU is received on a PortFast-enabled interface without BPDU Guard active, the switch detects another bridge device. PortFast operational status is immediately revoked, and the port falls back to standard IEEE 802.1D state transitions.
Falling back to normal STP port states (Blocking -> Listening -> Learning -> Forwarding) protects the network from potential Layer 2 loops.

Key Concept

PortFast BPDU Handling and Operational State Reversion
Question 1051Question →

A network engineer is auditing Layer 2 discovery protocol operation on a Cisco Catalyst switch connected to multi-vendor wireless access points and VoIP endpoints. The engineer executes the CLI command `show lldp entry AP-Floor2` on switch SW-1 and views the following output:

text
Capability codes:
(R) Router, (B) Bridge, (T) Telephone, (W) WLAN Access Point, (P) Repeater, (O) Other

Local Interface: Gi1/0/12
Chassis id: 0027.0d4f.8e10
Port id: Gi0/1
Port Description: GigabitEthernet0/1
System Name: AP-Floor2
System Description: Autonomous AP Software v15.3
Time remaining: 98 seconds
System Capabilities: B, W
Enabled Capabilities: W
Management Address: 10.1.20.15
Management Address Port VLAN ID (PVID): 20

Which statements accurately interpret the operational state and protocol fields in this command output? (Select TWO.)

Select all that apply

Show answer & explanation

Answer: The neighbor device is connected to local switch interface GigabitEthernet1/0/12, while GigabitEthernet0/1 identifies the port on the remote neighbor device.; The neighbor device advertises System Capabilities as both a Bridge and a WLAN Access Point, but currently functions with only its WLAN Access Point capability enabled.

Answer

The correct statements are that GigabitEthernet1/0/12 is the local switch interface while GigabitEthernet0/1 is the remote port ID, and that the neighbor supports Bridge and WLAN Access Point capabilities but operates with only WLAN Access Point enabled.
The output from `show lldp entry` provides Layer 2 neighbor discovery details defined by IEEE 802.1AB. The 'Local Interface' line specifies that switch port GigabitEthernet1/0/12 receives the frames, whereas 'Port id' indicates GigabitEthernet0/1 on the remote device. Additionally, the System Capabilities field shows all capabilities supported by the device hardware (Bridge and WLAN Access Point), while Enabled Capabilities indicates that only WLAN Access Point functionality is actively enabled.

Step-by-Step Solution

1
Analyze interface mapping in LLDP CLI output.
Identify 'Local Interface: Gi1/0/12' as the switch's local receiving port and 'Port id: Gi0/1' as the remote neighbor's transmitting interface.
Layer 2 discovery outputs distinguish between local interfaces and remote neighbor port identifiers to accurately identify physical topology connections.
2
Evaluate system and enabled capabilities codes.
System Capabilities lists 'B, W' (Bridge and WLAN Access Point), while Enabled Capabilities lists 'W'.
LLDP TLVs allow neighbor devices to report both their full hardware features and currently active functional roles.
3
Distinguish LLDP protocol parameters from CDP parameters.
Confirm LLDP operates under IEEE 802.1AB standard with a 120-second default holdtime (30s timer × 4 hold multiplier), contrasting CDP's 180-second default holdtime (60s timer × 3).
Recognizing protocol defaults prevents confusing open-standard LLDP data with Cisco proprietary CDP frames.

Key Concept

Interpretation of IEEE 802.1AB LLDP entry output and TLV field mappings
Estimated Time:2m 0s
Question 1052Question →

A network engineer is implementing a Variable Length Subnet Mask (VLSM) addressing scheme for a regional facility using the summary block 10.200.16.0/2210.200.16.0/22. Subnet A must support up to 120120 usable host addresses for a departmental LAN segment. Subnet B must support a point-to-point WAN link between two routers. Subnet A is allocated the lowest numerical range within the summary block, starting at 10.200.16.010.200.16.0. If Subnet B is assigned the next immediately adjacent subnet block with the tightest prefix length that satisfies its requirement, which IPv4 address is a valid host address for Subnet B?

Show answer & explanation

Answer: 10.200.16.13010.200.16.130

Answer

The IPv4 address 10.200.16.13010.200.16.130 is a valid usable host address for Subnet B.
The address 10.200.16.13010.200.16.130 is a valid usable host address on Subnet B. Subnet A requires 120120 usable host addresses, which requires 77 host bits (27−2=1262^7 - 2 = 126), resulting in a /25/25 subnet mask. Starting at 10.200.16.010.200.16.0, Subnet A occupies 10.200.16.010.200.16.0 through 10.200.16.12710.200.16.127. Subnet B starts immediately at 10.200.16.12810.200.16.128. Because Subnet B is a point-to-point link requiring 22 host IPs, a /30/30 mask (22 host bits) is assigned. The /30/30 block 10.200.16.128/3010.200.16.128/30 has usable host addresses 10.200.16.12910.200.16.129 and 10.200.16.13010.200.16.130.

Step-by-Step Solution

1
Determine the prefix length and address boundary for Subnet A
Subnet A uses a /25/25 mask, spanning 10.200.16.010.200.16.0 to 10.200.16.12710.200.16.127.
Subnet A requires 120120 usable host addresses. Using the formula 2h−2≥1202^h - 2 \ge 120, h=7h = 7 host bits are needed (27−2=1262^7 - 2 = 126). The prefix length is 32−7=/2532 - 7 = /25. Starting at 10.200.16.010.200.16.0, the subnet range runs from network ID 10.200.16.010.200.16.0 to broadcast address 10.200.16.12710.200.16.127.
2
Identify the starting network address and required mask for Subnet B
Subnet B network address is 10.200.16.12810.200.16.128 with a /30/30 prefix length.
The next immediately adjacent unallocated IP address is 10.200.16.12810.200.16.128. Subnet B needs 22 usable host addresses for a point-to-point link. Using 2h−2≥22^h - 2 \ge 2, h=2h = 2 host bits are needed (22−2=22^2 - 2 = 2). The prefix length is 32−2=/3032 - 2 = /30.
3
Calculate the valid host address range for Subnet B
Valid host addresses are 10.200.16.12910.200.16.129 and 10.200.16.13010.200.16.130.
For the network 10.200.16.128/3010.200.16.128/30, 10.200.16.12810.200.16.128 is the network address, 10.200.16.12910.200.16.129 is the first usable host, 10.200.16.13010.200.16.130 is the last usable host, and 10.200.16.13110.200.16.131 is the broadcast address.

Key Concept

VLSM block allocation and usable host range calculation for sequential subnets
Estimated Time:2m 0s
Question 1053Question →

An engineer is deploying a high-performance database server in a virtualized data center. To minimize latency and resource overhead, the virtualization software is installed directly onto the physical server hardware without an intervening host operating system. Which virtualization component is responsible for managing physical hardware resources and allocating them directly to the guest virtual machines in this architecture?

Show answer & explanation

Answer: Type 1 hypervisor

Answer

The correct architecture is a Type 1 hypervisor, which operates directly on server bare-metal hardware to allocate compute, memory, and network resources to virtual machines.
A Type 1 hypervisor (also known as a bare-metal hypervisor) installs directly onto the physical server hardware. It manages system resources—including CPU, RAM, and storage—and schedules guest virtual machines with minimal abstraction overhead, making it ideal for enterprise deployments.

Step-by-Step Solution

1
Analyze the deployment requirement from the scenario.
The requirement specifies installing virtualization software directly onto physical server hardware without an underlying host operating system.
Bare-metal deployments eliminate host operating system overhead to maximize hardware performance.
2
Distinguish between hypervisor execution models.
Type 1 hypervisors run directly on bare metal, while Type 2 hypervisors rely on an existing host OS (such as Windows or Linux).
Understanding the direct hardware interaction helps identify the correct component for low-latency enterprise server environments.

Key Concept

Type 1 vs Type 2 Hypervisor Architecture
Question 1054Question →

A network administrator is manually configuring a Cisco switch to become the root bridge for VLAN 10 using Rapid PVST+. Which value is valid to specify with the command `spanning-tree vlan 10 priority <value>`?

Show answer & explanation

Answer: 24576

Answer

The valid bridge priority setting is 24576, as Rapid PVST+ requires configurable priority values to be in increments of 4096.
In Rapid PVST+, the configurable bridge priority must be a multiple of 4096 (0,4096,8192,…,614400, 4096, 8192, \dots, 61440). The value 24576 is 6×40966 \times 4096, making it a valid configuration parameter. The switch automatically adds the VLAN ID (10) to the base priority to create the combined Bridge Identifier priority of 24586.

Step-by-Step Solution

1
Identify the Rapid PVST+ bridge priority structure requirement
Rapid PVST+ uses the 802.1t System ID Extension, dividing the 16-bit Bridge Priority field into a 4-bit priority component and a 12-bit VLAN ID component.
Because 4 bits are reserved for priority, values can only change by steps of 212=40962^{12} = 4096.
2
Evaluate the candidate values for multiples of 4096
24576/4096=624576 / 4096 = 6, which is an exact integer multiple.
The CLI requires entering the base priority multiplier (6×4096=245766 \times 4096 = 24576), and the switch will internally add VLAN 10 to yield a total priority of 24586.

Key Concept

Rapid PVST+ Bridge Priority Increment Calculation
Estimated Time:45s
Question 1055Question →

A network administrator is interconnecting two legacy Cisco routers directly using their GigabitEthernet0/0 interfaces (both configured as MDI ports) in a high-security environment where Auto-MDIX is manually disabled. The administrator needs to build a custom RJ-45 copper patch cable to achieve a functional 1000BASE-T connection between the devices. If the first end of the cable is terminated using the standard T568B pinout, which pin wiring scheme must be applied to the second end to guarantee full Gigabit Ethernet Layer 1 operation?

Show answer & explanation

Answer: Pins 1 and 2 crossed with pins 3 and 6, and pins 4 and 5 crossed with pins 7 and 8

Answer

Pins 1 and 2 crossed with pins 3 and 6, and pins 4 and 5 crossed with pins 7 and 8
For Gigabit Ethernet (1000BASE-T) links between two MDI devices (such as routers) where Auto-MDIX is turned off, a full 4-pair crossover cable is required. This configuration crosses Pair 1 (pins 1 and 2) with Pair 2 (pins 3 and 6), as well as Pair 3 (pins 4 and 5) with Pair 4 (pins 7 and 8).

Step-by-Step Solution

1
Identify the device roles and interface pinout mode (MDI vs MDI-X).
Both router GigabitEthernet interfaces act as MDI (Medium Dependent Interface) ports.
Like devices (router to router, switch to switch) require pin crossover on the cable when connected directly without Auto-MDIX.
2
Determine the physical medium transmission standard requirements (1000BASE-T).
1000BASE-T operates over Category 5e/6 UTP using all four pairs (8 wires) simultaneously for full-duplex transmission (BI_DA, BI_DB, BI_DC, BI_DD).
Unlike 10BASE-T/100BASE-TX which only utilize pairs 1-2 and 3-6, 1000BASE-T requires all four pairs to be properly paired and crossed.
3
Map the crossover pinout required for 1000BASE-T operation.
Pair 1 (pins 1, 2) swaps with Pair 2 (pins 3, 6), and Pair 3 (pins 4, 5) swaps with Pair 4 (pins 7, 8).
This guarantees that transmit and receive signals across all four bi-directional channels align correctly between the two MDI interfaces.

Key Concept

1000BASE-T Crossover Cabling Pinouts and MDI/MDI-X Interconnection
Question 1056Question →

A network administrator is allocated the IPv6 prefix 2001:db8:acad:4000::/582001:\text{db8}:\text{acad}:4000::/58 for a new branch location. The administrator needs to divide this block into standard /64/64 subnets for local LAN segments. How many /64/64 subnets can be created from this block?

Show answer & explanation

Answer: 64

Answer

64 subnets can be created from the given /58/58 prefix block.
Subtracting the assigned prefix length (/58) from the standard interface subnet prefix length (/64) results in 6 subnet bits (64−58=664 - 58 = 6). Computing 262^6 yields 64 total subnets.

Step-by-Step Solution

1
Calculate the number of subnetting bits.
64−58=664 - 58 = 6 bits.
Subtracting the starting prefix length (/58) from the target prefix length (/64) determines the number of bits available for subnetting.
2
Calculate the total number of subnets.
26=642^6 = 64 subnets.
Raising 2 to the power of the subnet bit count (262^6) provides the total number of valid /64/64 subnets.

Key Concept

IPv6 Subnetting and Prefix Length Calculation
Estimated Time:1m 0s
Question 1057Question →

A network engineer configures interface GigabitEthernet0/1 on Switch-1 with the commands `switchport mode trunk` and `switchport nonegotiate`. The connected interface GigabitEthernet0/1 on Switch-2 remains in its default configuration of `switchport mode dynamic auto`. What is the resulting operational state of interface GigabitEthernet0/1 on Switch-2?

Show answer & explanation

Answer: It operates as an access port because it does not receive Dynamic Trunking Protocol (DTP) frames from Switch-1 to trigger trunk negotiation.

Answer

Interface GigabitEthernet0/1 on Switch-2 operates as an access port because `switchport nonegotiate` on Switch-1 suppresses DTP frames, leaving Switch-2 in its default passive access state.
The command `switchport nonegotiate` turns off DTP frame generation on Switch-1. Because interface GigabitEthernet0/1 on Switch-2 is set to `dynamic auto`, it relies on receiving incoming DTP negotiation frames to transition to a trunking state. Receiving no DTP frames from Switch-1, Switch-2 stays in its default operational mode of access, resulting in a misconfiguration where Switch-1 trunks while Switch-2 acts as an access port.

Step-by-Step Solution

1
Analyze the DTP configuration on Switch-1
Switch-1 is configured statically as a trunk (`switchport mode trunk`) and DTP frame transmission is disabled using `switchport nonegotiate`.
The `nonegotiate` command stops the interface from sending DTP frames to neighboring devices.
2
Analyze the DTP operational behavior on Switch-2
Switch-2 is in `switchport mode dynamic auto`, which means it will form a trunk only if it receives a DTP request frame (desirable or trunk mode) from the remote switch.
Dynamic auto interfaces never actively originate DTP negotiation requests; they remain passive.
3
Determine the resulting link operational state
Because Switch-1 sends no DTP frames, Switch-2 never receives the signal to become a trunk and defaults to an operational access port.
A link connecting a static trunk with `nonegotiate` to a `dynamic auto` interface creates a mode mismatch where one side is trunking and the other is an access port.

Key Concept

802.1Q Trunking DTP Negotiation and Nonegotiate Interaction
Question 1058Question →

A network engineer is inspecting an IPv6 neighbor discovery cache entry on a Cisco switch and identifies a connected host with the SLAAC-generated link-local address fe80::1e1b:0dff:fe44:5566fe80::1e1b:0dff:fe44:5566. Based on the EUI-64 address generation standard, what is the original burned-in MAC address of the host's network interface card?

Show answer & explanation

Answer: 1c1b.0d44.5566

Answer

The original burned-in MAC address of the host is 1c1b.0d44.5566.
To reverse the EUI-64 process for the interface ID 1e1b:0dff:fe44:55661e1b:0dff:fe44:5566, first remove the 16-bit FFFEFFFE inserted in the middle to restore 48 bits: 1E−1B−0D−44−55−661E-1B-0D-44-55-66. Next, convert the first byte 1E1E to binary (0001 111020001\ 1110_2) and invert the 7th bit (counted from left to right), changing it from 1 to 0 to get 0001 110020001\ 1100_2 (1C1C). Reassembling the MAC address yields 1c1b.0d44.5566.

Step-by-Step Solution

1
Identify the 64-bit interface identifier portion of the IPv6 link-local address.
The interface identifier is 1e1b:0dff:fe44:5566.
In a link-local address (fe80::/64fe80::/64), the last 64 bits represent the interface identifier.
2
Remove the 16-bit FFFEFFFE hexadecimal value inserted into the midpoint during EUI-64 derivation.
Removing FFFE from 1e1b:0dff:fe44:5566 yields the 48-bit pattern 1E-1B-0D-44-55-66.
EUI-64 generation inserts FFFEFFFE between the OUI (first 24 bits) and the vendor-assigned extension identifier (last 24 bits).
3
Invert the 7th bit (Universal/Local bit) of the first byte.
The first byte 1E1E (0001 111020001\ 1110_2) with its 7th bit inverted becomes 1C1C (0001 110020001\ 1100_2).
During EUI-64 formation, the 7th bit of the first MAC octet is inverted (0 for universal/burned-in becomes 1 for EUI-64). Reversing the process converts the 1 back to 0.
4
Reconstruct the 48-bit MAC address in standard Cisco dotted-quad hexadecimal notation.
Combining 1C−1B−0D−44−55−661C-1B-0D-44-55-66 into Cisco MAC format gives 1c1b.0d44.5566.
Cisco IOS formats MAC addresses as three groups of four hexadecimal digits separated by dots.

Key Concept

Reversing EUI-64 Interface Identifier Derivation to Extract Original MAC Address
Question 1059Question →

A network engineer is configuring a point-to-point WAN link between two branch routers using the 192.168.10.4/30192.168.10.4/30 network segment. Which IPv4 address represents a valid usable host address for one of the router interfaces?

Show answer & explanation

Answer: 192.168.10.5192.168.10.5

Answer

The address 192.168.10.5192.168.10.5 is a valid usable host IPv4 address in the 192.168.10.4/30192.168.10.4/30 subnet.
In a /30/30 subnet starting at 192.168.10.4192.168.10.4, the total block size is 44 IP addresses (192.168.10.4192.168.10.4 through 192.168.10.7192.168.10.7). The network address is 192.168.10.4192.168.10.4 and the broadcast address is 192.168.10.7192.168.10.7. The valid usable host IP addresses for router interfaces are 192.168.10.5192.168.10.5 and 192.168.10.6192.168.10.6. Therefore, 192.168.10.5192.168.10.5 is a correct host address.

Step-by-Step Solution

1
Determine the block size for a /30/30 prefix length.
A /30/30 mask uses 3030 network bits and 22 host bits (32−30=232 - 30 = 2). The block size is 22=42^2 = 4.
Calculating the block size defines the size and boundaries of the subnet segment.
2
Identify the network address and broadcast address for the segment.
For the network starting at 192.168.10.4192.168.10.4, the block ends before 192.168.10.8192.168.10.8. The network address is 192.168.10.4192.168.10.4 and the broadcast address is 192.168.10.7192.168.10.7.
The first address in the block is reserved for the network ID and the last address is reserved for broadcast.
3
Determine the range of valid usable host IP addresses.
Usable host addresses span from 192.168.10.5192.168.10.5 through 192.168.10.6192.168.10.6.
Usable host addresses are the IP addresses strictly between the network ID and the broadcast address.

Key Concept

IPv4 Subnet Boundaries and Usable Host Address Ranges
Question 1060Question →

A network engineer configures an interface on a Cisco Catalyst switch operating in VTP Client mode by executing the command switchport access vlan 50 under interface configuration mode. Upon verifying the port status using the show interfaces gigabitethernet 1/0/1 switchport command, the output indicates Access Mode VLAN: 50 (Inactive). What is the root cause of this inactive status, and how should it be resolved?

Show answer & explanation

Answer: VLAN 50 does not exist in the VLAN database propagated by the VTP Server; VLAN 50 must be created on the VTP Server switch.

Answer

VLAN 50 does not exist in the VLAN database propagated by the VTP Server; VLAN 50 must be created on the VTP Server switch.
When a port is assigned to an access VLAN on a Cisco Catalyst switch, the VLAN must exist in the VLAN database for the port to forward traffic. On switches in VTP Server or VTP Transparent mode, executing 'switchport access vlan X' automatically creates VLAN X in the database if it does not already exist. However, switches operating in VTP Client mode cannot modify the local VLAN database directly or auto-create VLANs. If the assigned VLAN does not exist in the VTP database advertised by the VTP Server, the switchport output displays the access mode VLAN as '(Inactive)'. To resolve this issue, VLAN 50 must be created on the VTP Server so that it is propagated to the VTP Client switch.

Step-by-Step Solution

1
Analyze the switch operating mode and CLI output
The switch operates in VTP Client mode, and interface Gi1/0/1 displays 'Access Mode VLAN: 50 (Inactive)'.
VTP Client switches learn VLAN definitions dynamically from VTP Server advertisements and do not allow local creation or auto-creation of VLAN entries.
2
Determine the cause of the '(Inactive)' VLAN status
On Cisco switches, an access VLAN is marked 'Inactive' when a port is assigned to a VLAN ID that is not present in the local VLAN database.
While switches in VTP Server or Transparent mode automatically create a missing VLAN upon interface assignment, VTP Client switches cannot auto-create VLAN entries.
3
Identify the required corrective action
Configure VLAN 50 on the VTP Server switch.
Once VLAN 50 is created on the VTP Server, it will be advertised via VTP updates to the client switch, populating the local VLAN database and activating the port.

Key Concept

VLAN Database Inactive Status and VTP Client Behavior
PreviousPage 53 / 100Next
All practice questions — Cisco CCNA | Examkin