Network Access

400 questions

All types400 Multiple choice204 Multiple select91 Matching23 Ordering82

A network engineer is connecting multiple physical distribution system ports of a Cisco AireOS Wireless LAN Controller (WLC) to an upstream Cisco Catalyst switch using Link Aggregation (LAG). Which two configuration requirements must be implemented on the switch interfaces to establish successful aggregation and traffic transport? (Select two.)

Select all that apply

Configure the EtherChannel bundle mode on the switch interfaces to static 'on' state.

Configure the EtherChannel negotiation mode on the switch interfaces to LACP active mode.

Configure the switch interface or port-channel as an 802.1Q trunk port to carry traffic across multiple VLANs.

Set the native VLAN on the switch trunk port to match the tagged dynamic wireless client VLAN.

Show answer & explanation

Answer: Configure the EtherChannel bundle mode on the switch interfaces to static 'on' state.; Configure the switch interface or port-channel as an 802.1Q trunk port to carry traffic across multiple VLANs.

Answer

The correct requirements are configuring the switch interfaces to static EtherChannel mode ('on') and setting the link to operate as an 802.1Q trunk.

Cisco AireOS WLCs utilize static Link Aggregation (LAG) and do not support dynamic EtherChannel negotiation protocols like LACP or PAgP. Consequently, switch ports connected to an AireOS controller must be set to static mode ('channel-group mode on'). Furthermore, since LAG bundles all physical controller ports into a single logical connection handling multiple SSIDs and management traffic, the upstream switch interface must be configured as an 802.1Q trunk port.

Step-by-Step Solution

Determine controller LAG protocol support.

AireOS WLCs support static Link Aggregation (LAG) without using dynamic negotiation protocols such as LACP or PAgP.

Because the controller does not exchange LACP or PAgP packets, the switch ports must force EtherChannel creation using 'channel-group mode on'.

Determine switchport trunking configuration.

Configure the switch port-channel as an 802.1Q trunk carrying management and dynamic client VLANs.

Enabling LAG on a WLC aggregates all physical distribution ports into a single trunk link capable of carrying untagged management traffic and tagged dynamic client VLAN traffic.

Key Concept

Cisco AireOS WLC Link Aggregation (LAG) and Switchport Trunking Requirements

Question 382Question →

A network administrator needs to create VLAN 35 named SALES on a Cisco Catalyst switch and assign interface FastEthernet0/5 as a static access port in this VLAN, starting from Privileged EXEC mode (`Switch#`). Place the following Cisco IOS CLI commands in the correct sequential order from first to last.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct command sequence begins with entering global configuration mode using `configure terminal`, creating VLAN 35 using `vlan 35`, setting the VLAN name with `name SALES`, entering the interface context via `interface FastEthernet0/5`, configuring the interface operating mode using `switchport mode access`, and finally assigning the interface to the VLAN using `switchport access vlan 35`.

In Cisco IOS, configuration follows a strict hierarchy. From Privileged EXEC mode (`Switch#`), global configuration mode must first be accessed via `configure terminal`. Once in global configuration mode, `vlan 35` creates the VLAN and shifts context to VLAN sub-mode (`config-vlan`), where `name SALES` sets the VLAN name. The administrator then navigates directly to interface configuration mode using `interface FastEthernet0/5`. Within interface configuration mode (`config-if`), the port mode is explicitly configured using `switchport mode access`, followed by assigning the port to VLAN 35 with `switchport access vlan 35`.

Step-by-Step Solution

Enter Global Configuration Mode

Prompt changes from `Switch#` to `Switch(config)#`.

Global configuration commands like VLAN creation and interface navigation can only be initiated from global configuration mode.

Create VLAN 35

Prompt changes from `Switch(config)#` to `Switch(config-vlan)#`.

Issuing `vlan 35` creates the Layer 2 broadcast domain in the VLAN database and opens VLAN configuration mode.

Assign VLAN Name

VLAN 35 is assigned the name SALES in the switch database.

The `name` command must be run while in VLAN configuration mode.

Navigate to Interface FastEthernet0/5 Context

Prompt changes to `Switch(config-if)#`.

Interface parameters can only be altered when inside the specific interface configuration sub-mode.

Set Port Operational Mode to Access

Dynamic Trunking Protocol (DTP) negotiation is disabled or restricted, locking the port to non-trunking access mode.

Executing `switchport mode access` explicitly sets the interface into access mode before or during VLAN membership assignment.

Associate Interface with VLAN 35

Traffic untagged on FastEthernet0/5 is assigned to VLAN 35.

The command `switchport access vlan 35` binds the interface to the specified access VLAN.

Key Concept

Cisco IOS CLI command hierarchy for VLAN creation and static access port configuration

Question 383Question →

A non-root switch running Rapid PVST+ receives BPDUs on multiple interfaces with identical path costs to the Root Bridge. Place the tie-breaker criteria in the correct sequential order (from first evaluated to last evaluated) that the switch uses to select its Root Port.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct order of evaluation for selecting a Root Port in Rapid PVST+ is: 1) Lowest cumulative root path cost, 2) Lowest sender Bridge ID (BID), 3) Lowest sender port priority, and 4) Lowest sender port number.

When a non-root switch running Rapid PVST+ must select a Root Port from multiple candidate interfaces, it follows a strict four-step tie-breaker sequence: first, it checks for the lowest cumulative root path cost; second, the lowest sender Bridge ID (BID); third, the lowest sender port priority; and fourth, the lowest sender port number (interface ID).

Step-by-Step Solution

Evaluate Root Path Cost

The switch identifies paths with the lowest total cost to reach the Root Bridge.

STP primary objective is forwarding traffic over the shortest cost path.

Evaluate Sender Bridge ID

If path costs are equal across multiple candidate ports, compare neighboring switches' BIDs.

Breaks ties when multiple neighboring switches offer equal-cost paths.

Evaluate Sender Port Priority

If connected to the same neighbor over multiple links, compare the neighbor's port priority values.

Differentiates multiple links arriving from a single neighboring switch.

Evaluate Sender Port Number

If sender port priority values are identical (default 128), select the port connected to the lower sender port number.

Provides a definitive final tie-breaker for parallel connections.

Key Concept

Rapid PVST+ Root Port Selection Tie-Breaker Sequence

Question 384Question →

A network administrator is inspecting a Cisco Catalyst switch port connected to a desktop computer assigned to VLAN 50. Output from the `show interfaces gigabitEthernet 1/0/12 switchport` command reveals that the interface is operating under default settings with an administrative mode of `dynamic auto` and an access VLAN of 1. Which configuration commands must be entered in interface configuration mode to assign this port to VLAN 50 as a dedicated static access port?

switchport mode access
switchport access vlan 50

switchport access vlan 50

switchport mode trunk
switchport trunk native vlan 50

switchport mode dynamic desirable
switchport access vlan 50

Show answer & explanation

Answer: switchport mode access
switchport access vlan 50

Answer

The commands 'switchport mode access' followed by 'switchport access vlan 50' correctly assign the interface to VLAN 50 as a static access port.

To properly configure an end-user device port in Cisco IOS, administrators should explicitly define the switchport mode as access using 'switchport mode access' and then assign the access VLAN with 'switchport access vlan 50'. This prevents unwanted DTP negotiation and ensures the interface remains a dedicated access port.

Step-by-Step Solution

Set the administrative mode to static access.

Disables Dynamic Trunking Protocol (DTP) negotiation on the interface.

By default, Cisco Catalyst interfaces are configured as dynamic auto or dynamic desirable. Using 'switchport mode access' forces the port to act strictly as a Layer 2 access port.

Assign the access port to the target VLAN.

Places untagged traffic entering GigabitEthernet1/0/12 into VLAN 50.

The command 'switchport access vlan 50' associates untagged frames received on this interface with VLAN 50.

Key Concept

Configuring Cisco IOS L2 access ports and overriding DTP dynamic modes

Estimated Time:1m 0s

Question 385Question →

A network administrator is connecting a Cisco Catalyst 9800 Series Wireless LAN Controller to an upstream Cisco Catalyst switch using link aggregation (LAG) with LACP. In what logical order should the administrator execute the steps on the Catalyst switch to provision the EtherChannel interface and physical member ports?

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence begins with creating the logical port-channel interface on the switch, applying trunking and VLAN parameters to that logical interface, selecting the physical member interfaces, adding the physical interfaces to the EtherChannel using active LACP mode, and finally verifying bundle operation with the 'show etherchannel summary' command.

To establish link aggregation between a Cisco Catalyst switch and a Cisco Wireless LAN Controller using LACP, standard configuration methodology requires initializing the logical port-channel interface first. Trunking settings (such as switchport mode trunk and VLAN assignments) are defined on the logical port-channel. Next, the target physical member interfaces are selected and bound to the channel group using active LACP mode. Finally, running operational verification commands confirms proper link aggregation state.

Step-by-Step Solution

Create the virtual port-channel interface

The logical interface Port-channel 1 is initialized.

Creating the logical interface first provides the administrative entity where trunking parameters will be defined.

Configure trunking properties on the port-channel

The port-channel interface is set to switchport mode trunk with explicit native and allowed VLAN parameters.

Defining trunk settings directly on the port-channel interface guarantees uniform configuration for all associated physical ports.

Select physical switch interfaces

The physical ports connected to the wireless controller are selected via interface range configuration mode.

Grouping physical interfaces prepares them for enrollment into the EtherChannel bundle.

Bind physical ports to the channel group using LACP

The command 'channel-group 1 mode active' enables dynamic LACP negotiation on the physical ports.

LACP active mode allows the switch to initiate negotiation with the Wireless LAN Controller.

Verify EtherChannel operation

Output displays flag 'SU' for the port-channel and flag 'P' for each active member port.

Verifying status confirms that LACP negotiation succeeded and traffic can be forwarded across the aggregated links.

Key Concept

Cisco switch EtherChannel and LACP configuration for WLC trunking

Question 386Question →

A network administrator needs to assign interface GigabitEthernet1/0/8 on a Cisco Catalyst switch to VLAN 70 (named RESEARCH) as a static access port. The configuration must force the interface into access mode and statically assign it to VLAN 70. Which TWO commands must be entered in interface configuration mode to complete this setup?

Select all that apply

switchport mode access

switchport trunk native vlan 70

switchport access vlan 70

vlan 70

Show answer & explanation

Answer: switchport mode access; switchport access vlan 70

Answer

The correct commands to execute in interface configuration mode are 'switchport mode access' and 'switchport access vlan 70'.

Configuring an access port on a Cisco switch requires defining the port behavior as access mode ('switchport mode access') and specifying the target VLAN assignment ('switchport access vlan 70'). Together, these commands ensure untagged traffic on the port belongs exclusively to VLAN 70.

Step-by-Step Solution

Set the interface mode to access

Interface is explicitly designated as an access port using 'switchport mode access'.

Ensures the port operates exclusively as an access interface and disables DTP negotiation into trunking mode.

Assign the specific access VLAN membership

Interface is associated with VLAN 70 using 'switchport access vlan 70'.

Directs untagged traffic entering or leaving GigabitEthernet1/0/8 into broadcast domain VLAN 70.

Key Concept

Configuring static access ports in Cisco IOS requires enforcing access mode and setting the access VLAN membership at the interface configuration prompt.

Question 387Question →

A network administrator is analyzing the operational characteristics of a Cisco Catalyst switch block running Rapid PVST+. Which two statements accurately describe Rapid PVST+ port roles and bridge priority structures?

Select all that apply

An Alternate port remains in the Discarding state while receiving BPDUs from neighboring switches to provide an alternate path to the Root Bridge.

A Backup port receives BPDUs from the same switch on a shared medium segment to offer redundant connectivity for the designated segment.

Configuring bridge priorities for VLANs in Rapid PVST+ must be specified in increments of 2048 to allow space for the 12-bit System ID Extension.

Enabling PortFast on switch-to-switch trunk ports causes the interface to transition immediately into the Learning state to accelerate STP convergence.

Show answer & explanation

Answer: An Alternate port remains in the Discarding state while receiving BPDUs from neighboring switches to provide an alternate path to the Root Bridge.; A Backup port receives BPDUs from the same switch on a shared medium segment to offer redundant connectivity for the designated segment.

Answer

The correct statements are that an Alternate port remains in the Discarding state while receiving BPDUs to provide an alternate root path, and a Backup port receives BPDUs from its own switch on a shared segment to provide redundant segment access.

In Rapid PVST+, an Alternate port receives BPDUs from neighboring switches to serve as an instant backup to the Root Port while maintaining a Discarding state. A Backup port receives BPDUs from its own switch across a shared collision domain (such as a hub) to serve as a backup to a Designated port.

Step-by-Step Solution

Evaluate the operational characteristics of Rapid PVST+ Alternate and Backup port roles.

Alternate ports receive BPDUs from other switches to back up the Root Port (in Discarding state). Backup ports receive BPDUs from the local switch on shared media to back up a Designated port.

RSTP (802.1w) defines distinct roles for discarded links based on whether the incoming BPDUs originate from an external switch (Alternate) or the local switch itself (Backup).

Evaluate the calculation rules for System ID Extension and Bridge Priority in Cisco switches.

Bridge priority uses the 4 most significant bits of the 16-bit priority field, requiring configured values to be multiples of 4096 (

2^{12}

Values like 2048 are invalid because the lower 12 bits are strictly reserved for carrying the VLAN ID.

Analyze PortFast state transitions and placement rules.

PortFast transitions ports directly to Forwarding (bypassing Discarding and Learning) and is intended for end-user edge devices.

Applying PortFast to switch-to-switch trunks risks immediate Layer 2 loops during topology changes.

Key Concept

Rapid PVST+ Port Roles and System ID Extension Rules

Estimated Time:1m 30s

Question 388Question →

Two Cisco Catalyst switches running Rapid PVST+ are configured with an identical base bridge priority of $4096$ for VLAN $30$ . Which factor ultimately determines which switch is elected as the Root Bridge for VLAN $30$ ?

The switch with the lowest MAC address, because both switches have an identical total Bridge Priority of

4126

The switch with the highest MAC address, because Rapid PVST+ prefers higher physical hardware addresses during tie-breakers.

The switch with the lowest port ID connected to the neighbor, because port IDs break priority ties before MAC addresses are evaluated.

The switch configured first, because Rapid PVST+ retains the active Root Bridge role until an administrative preempt command is issued.

Show answer & explanation

Answer: The switch with the lowest MAC address, because both switches have an identical total Bridge Priority of $4126$ .

Answer

The switch with the lowest MAC address will be elected as the Root Bridge because both switches generate an identical total Bridge Priority of

4126

The correct answer identifies that both switches have a total Bridge Priority of

4126

(

4096

base priority +

30

VLAN ID extension). Because their priorities are equal, the tie-breaker rule dictates that the switch with the lowest MAC address is selected as the Root Bridge.

Step-by-Step Solution

Calculate the total Bridge Priority for each switch

Total Priority = Base Priority (

4096

) + System ID Extension (

30

) =

4126

Rapid PVST+ automatically adds the VLAN ID to the base priority step.

Compare the total Bridge IDs of both switches

Both switches share the exact same Bridge Priority (

4126

When total priorities match, the election moves to the final component of the Bridge ID.

Apply the Root Bridge tie-breaker rule

The switch with the numerically lowest MAC address wins the Root Bridge election.

In Spanning Tree election criteria, lower numeric values are always preferred.

Key Concept

Rapid PVST+ Root Bridge Election and System ID Extension Calculation

Question 389Question →

A network engineer is configuring link aggregation (LAG) on a Cisco Wireless LAN Controller (WLC) to connect to a Cisco Catalyst switch stack. The WLC distribution system ports are connected to ports GigabitEthernet1/0/1 through GigabitEthernet1/0/4 on the switch stack.

Which behavior accurately describes how the Wireless LAN Controller manages interface traffic and link failures when LAG is enabled?

All distribution system ports are combined into a single logical port channel, and if an individual physical link fails, traffic is dynamically redistributed across the remaining active links without interrupting wireless traffic.

Each distribution system port acts as a dedicated primary interface for a specific WLAN, and link failures require manual failover reassignment of the affected WLAN to an operational backup port.

The controller negotiates active and standby links using LACP, keeping two ports active while holding two ports in a standby state until an active link fails.

Untagged AP management frames are dropped by the switch trunk unless each physical distribution port is configured with a unique native VLAN setting across the member ports.

Show answer & explanation

Answer: All distribution system ports are combined into a single logical port channel, and if an individual physical link fails, traffic is dynamically redistributed across the remaining active links without interrupting wireless traffic.

Answer

When Link Aggregation (LAG) is enabled on a Wireless LAN Controller, all physical distribution system ports are combined into a single logical EtherChannel trunk. Traffic across all configured WLANs and management interfaces is load-balanced across the active links. If any physical port in the bundle experiences a failure, the controller and upstream switch immediately re-route traffic over the remaining operational member links without dropping client sessions or requiring manual intervention.

Step-by-Step Solution

Identify the operational characteristics of Link Aggregation (LAG) on a Wireless LAN Controller.

Enabling LAG merges all physical distribution system ports into a single logical EtherChannel/port-channel interface.

Bundling ports provides both increased aggregate throughput and full link redundancy for all controller-managed VLANs.

Analyze how traffic distribution and fault tolerance function within the unified LAG bundle.

If a physical link within the LAG fails, the WLC immediately redistributes client and management traffic over the remaining operational links.

Redistribution happens transparently at Layer 2 without requiring manual remapping of WLANs or AP management interfaces.

Key Concept

WLAN Infrastructure Connections and LAG Operation

Estimated Time:1m 0s

Question 390Question →

A network engineer executes the `show interfaces FastEthernet0/10 switchport` command on a Cisco Catalyst switch to verify port settings after assigning it to a departmental network. The partial output displays the following parameters:

Name: Fa0/10
Switchport: Enabled
Administrative Mode: dynamic auto
Operational Mode: static access
Access Mode VLAN: 40 (FINANCE)

Which interface configuration command must the engineer enter on FastEthernet0/10 to statically force the interface into access mode and disable Dynamic Trunking Protocol (DTP) negotiation?

switchport mode access

switchport access vlan 40

switchport trunk native vlan 40

switchport nonegotiate

Show answer & explanation

Answer: switchport mode access

Answer

The command 'switchport mode access' statically configures the interface into access mode and disables DTP dynamic trunk negotiation.

The output indicates that the administrative mode is currently 'dynamic auto', meaning the port is dynamically operating in access mode only because the connected neighbor is not actively negotiating a trunk. Executing 'switchport mode access' under interface configuration mode statically forces the interface into access mode, overriding DTP dynamic negotiation.

Step-by-Step Solution

Analyze the CLI output for administrative versus operational state.

The administrative mode is currently set to 'dynamic auto' (default on many Cisco Catalyst switches), while the operational mode is currently operating as 'static access' because the connected endpoint is not attempting DTP negotiation.

An interface in 'dynamic auto' mode is willing to become a trunk if the neighboring device actively requests it (e.g., dynamic desirable or trunk mode).

Determine the required CLI command to hardcode static access mode.

Entering interface configuration mode and executing 'switchport mode access' explicitly locks the administrative mode to static access.

Hardcoding access mode turns off DTP negotiation attempts to form a trunk, improving security and port stability.

Key Concept

Disabling DTP Negotiation and Statically Hardcoding Access Ports

Estimated Time:1m 0s

Question 391Question →

A network engineer connects two Cisco Catalyst switches using a point-to-point GigabitEthernet link running Rapid PVST+. Place the steps of the Rapid PVST+ Proposal and Agreement handshaking process in the correct chronological order from first to last.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence for the Rapid PVST+ Proposal-Agreement handshake is: 1) Upstream switch sends a Proposal BPDU, 2) Downstream switch puts non-edge designated ports into Discarding state (sync), 3) Downstream switch sends an Agreement BPDU, 4) Upstream switch immediately transitions its designated port to Forwarding.

Rapid PVST+ achieves rapid convergence on full-duplex point-to-point links via an explicit handshake. First, an upstream switch sends a Proposal BPDU. Second, the receiving downstream switch performs synchronization by forcing all non-edge designated ports into the Discarding state. Third, the downstream switch returns an Agreement BPDU. Finally, the upstream switch receives the Agreement and immediately transitions its designated port to Forwarding.

Step-by-Step Solution

Initiate Handshake

The upstream switch transmits a configuration BPDU with the Proposal bit set on a point-to-point link.

Rapid PVST+ uses explicit handshaking on point-to-point links rather than waiting for 802.1D forward delay timers.

Perform Synchronization

The receiving (downstream) switch blocks all non-edge designated ports, putting them into the Discarding state.

Enforcing the synchronization (sync) state isolates the local switch topology to ensure no temporary switching loops are formed.

Send Agreement

The downstream switch sends a BPDU back with the Agreement bit set.

This confirms to the upstream neighbor that the downstream switch has isolated its local ports and accepted the proposal.

Transition to Forwarding

The upstream switch transitions its designated port directly to the Forwarding state.

Receiving an explicit Agreement allows immediate state transition without waiting for timer expiration.

Key Concept

Rapid PVST+ (802.1w) Proposal-Agreement Synchronization Process

Estimated Time:1m 30s

Question 392Question →

A network administrator is inspecting interface configuration settings on a Cisco Catalyst switch after a user host on FastEthernet0/12 fails to communicate with devices in the target network. The output from the command `show interfaces FastEthernet0/12 switchport` indicates the following:

text
Name: Fa0/12
Switchport: Enabled
Administrative Mode: dynamic auto
Operational Mode: static access
Access Mode VLAN: 1 (default)

Which combination of interface configuration commands must the administrator execute on FastEthernet0/12 to explicitly set the port as a static access port and assign it to VLAN 45?

switchport mode access
switchport access vlan 45

switchport mode access
switchport trunk native vlan 45

vlan 45
switchport access vlan 45

switchport mode dynamic desirable
switchport access vlan 45

Show answer & explanation

Answer: switchport mode access
switchport access vlan 45

Answer

To configure FastEthernet0/12 as a static access port in VLAN 45, the administrator must enter interface configuration mode for FastEthernet0/12 and apply 'switchport mode access' followed by 'switchport access vlan 45'.

To configure a switch port as a static access member of a specific VLAN, Cisco IOS requires two commands under interface configuration mode: 'switchport mode access' to define the operational mode as access, and 'switchport access vlan <vlan-id>' to associate the interface with the specific VLAN ID.

Step-by-Step Solution

Change interface operational mode to static access

Disables dynamic trunking negotiation attempts on the interface and hardcodes it as an access port

The 'switchport mode access' command forces the interface into static access mode.

Assign the interface to the designated broadcast domain

Traffic received on FastEthernet0/12 is tagged/placed into VLAN 45

The 'switchport access vlan 45' command specifies VLAN 45 as the access VLAN for untagged frames.

Key Concept

Cisco IOS Switchport Access Mode and VLAN Membership Configuration

Question 393Question →

A network administrator is setting up a branch office deployment with Cisco Access Points (APs) operating in FlexConnect mode. The APs need to locally switch traffic for client WLANs mapped to corporate VLAN 20 and guest VLAN 30, while using VLAN 10 for AP management and CAPWAP control traffic back to the WLC. Which switch port configuration must be applied to the switch interface connected to each FlexConnect AP?

Configure the switch port as an 802.1Q trunk port with Native VLAN 10 and allowed VLANs 10, 20, and 30.

Configure the switch port as an access port assigned to VLAN 10, allowing CAPWAP to tunnel both management and locally switched data traffic.

Configure an LACP EtherChannel bundle on the switch port using 'channel-group mode active' to carry multi-VLAN traffic to the AP.

Configure the switch port as an 802.1Q trunk port with Native VLAN 20 and untagged management traffic mapped to VLAN 30.

Show answer & explanation

Answer: Configure the switch port as an 802.1Q trunk port with Native VLAN 10 and allowed VLANs 10, 20, and 30.

Answer

The switch port must be configured as an 802.1Q trunk port with Native VLAN 10 (for untagged AP management/CAPWAP traffic) and allowed VLANs 10, 20, and 30 for local client traffic switching.

FlexConnect APs configured for local switching handle client traffic locally at the branch level. To support multiple SSIDs mapped to different VLANs (VLAN 20 and 30) alongside AP management traffic (VLAN 10), the connected switch port must be an 802.1Q trunk. Untagged AP management traffic maps to the native VLAN (VLAN 10), while client traffic is tagged with its respective local VLAN IDs.

Step-by-Step Solution

Identify the operational mode of the Access Point.

The AP is in FlexConnect mode performing local switching for client traffic.

FlexConnect APs process VLAN tags locally on their physical Ethernet interfaces for traffic sent directly to the local switch infrastructure.

Determine the interface type required on the switch.

An 802.1Q trunk interface is required because multiple VLANs (VLAN 10, 20, 30) must traverse the single link connecting the AP.

Access ports can only carry a single VLAN, which is insufficient for multi-VLAN local switching.

Determine Native VLAN assignment for AP management.

Set Native VLAN to VLAN 10 on the switch trunk port.

Cisco APs transmit untagged management traffic by default. The native VLAN on the switch trunk port ensures untagged packets from the AP are placed onto management VLAN 10.

Key Concept

FlexConnect AP Infrastructure Switch Port Trunking Requirements

Question 394Question →

A network administrator issues the command `spanning-tree vlan 20 priority 16384` on a Cisco Catalyst switch running Rapid PVST+. What priority value will be carried in the Bridge Identifier (BID) field of outgoing BPDUs for VLAN 20?

16404

16384

16364

32788

Show answer & explanation

Answer: 16404

Answer

The effective priority value carried in the Bridge Identifier for VLAN 20 is 16404.

Rapid PVST+ uses the 802.1t System ID Extension mechanism, which appends the 12-bit VLAN ID directly to the 4-bit base bridge priority. Adding the configured base priority of 16384 to the VLAN ID of 20 yields a total priority value of 16404 in transmitted BPDUs.

Step-by-Step Solution

Identify the base Bridge Priority configured on the switch.

The base priority configured via CLI is

16384

The command `spanning-tree vlan 20 priority 16384` sets the base priority component of the Bridge ID.

Determine the System ID Extension value for the VLAN.

The System ID Extension value equals the VLAN number, which is

20

Rapid PVST+ uses 802.1t System ID Extension to carry unique STP instances per VLAN without consuming extra MAC addresses.

Calculate the total Bridge Priority by adding the base priority to the System ID Extension.

16384 + 20 = 16404

The 16-bit priority structure combines the 4-bit priority multiplier with the 12-bit VLAN identifier.

Key Concept

System ID Extension and Bridge Priority Calculation in Rapid PVST+

Question 395Question →

A network engineer is configuring a Cisco Catalyst switch to connect end-user workstations. The workstations must belong to VLAN 25, which should be named HR. Which two CLI commands or command sequences must be performed on the switch to complete this setup correctly?

Select all that apply

In global configuration mode, execute `vlan 25` followed by `name HR`.

In interface configuration mode for GigabitEthernet0/1, execute `switchport access vlan 25`.

In interface configuration mode for GigabitEthernet0/1, execute `switchport trunk native vlan 25`.

In interface configuration mode for GigabitEthernet0/1, execute `ip address 192.168.25.1 255.255.255.0`.

Show answer & explanation

Answer: In global configuration mode, execute `vlan 25` followed by `name HR`.; In interface configuration mode for GigabitEthernet0/1, execute `switchport access vlan 25`.

Answer

To properly set up an access port in VLAN 25, VLAN 25 must be created in global configuration mode (`vlan 25` / `name HR`), and the interface must be assigned to that VLAN using `switchport access vlan 25` in interface configuration mode.

Configuring an access port requires defining the VLAN in global configuration mode (`vlan 25` and `name HR`) and assigning the physical interface to that VLAN using `switchport access vlan 25`.

Step-by-Step Solution

Enter global configuration mode and define VLAN 25 with its name.

VLAN 25 is created and stored in the switch VLAN database.

Creating the VLAN ensures the broadcast domain exists before or upon assigning ports to it.

Enter interface configuration mode and assign the interface to VLAN 25.

Interface GigabitEthernet0/1 is placed into access mode for VLAN 25.

The `switchport access vlan 25` command specifies which VLAN untagged frames received on the port belong to.

Key Concept

VLAN Creation and Access Port Assignment

Estimated Time:1m 15s

Question 396Question →

A network administrator is evaluating the operational behavior and port roles of Rapid PVST+ on Cisco Catalyst switches. Which two statements regarding Rapid PVST+ operations are correct?

Select all that apply

An Alternate port functions as a backup path to the root bridge and can rapidly transition to the root port role if the active root port fails.

Designated ports utilize an explicit proposal and agreement handshake on point-to-point links to transition directly to the forwarding state.

PortFast should be configured on interswitch trunk links to eliminate spanning tree convergence delays between switches.

The switch bridge priority for a VLAN can be set to any arbitrary integer value between 0 and 65535, such as 5000.

Show answer & explanation

Answer: An Alternate port functions as a backup path to the root bridge and can rapidly transition to the root port role if the active root port fails.; Designated ports utilize an explicit proposal and agreement handshake on point-to-point links to transition directly to the forwarding state.

Answer

The two correct statements are that an Alternate port acts as a backup path to the root bridge, and that Designated ports use a proposal and agreement handshake on point-to-point links for rapid state transitions.

Rapid PVST+ defines an Alternate port as a discarded port receiving BPDUs from another switch, providing a backup path toward the root bridge. Additionally, Rapid PVST+ uses a proposal/agreement handshake on point-to-point links to bypass legacy 802.1D listening/learning timers and achieve rapid convergence.

Step-by-Step Solution

Analyze Rapid PVST+ port roles and state transition mechanisms.

Identified that Alternate ports offer immediate backup paths to the root bridge, and point-to-point links use proposal/agreement sync mechanisms for fast convergence.

Rapid PVST+ (802.1w implementation per VLAN) replaces timer-based convergence with explicit sync handshakes and active alternate backup paths.

Evaluate misconfigurations and priority calculations.

Confirmed that PortFast on trunk links creates loops and priority values must strictly follow 4096 increments due to the System ID Extension.

Bridge priorities consist of a 4-bit priority field (increments of 4096) combined with a 12-bit VLAN ID field.

Key Concept

Rapid PVST+ Port Roles and Sync Handshake Mechanics

Question 397Question →

A network engineer needs to configure link aggregation (LAG) on a Cisco Catalyst switch connected to a Cisco AireOS Wireless LAN Controller (WLC). Arrange the following configuration steps in the correct logical order from first to last to ensure a functional static EtherChannel interface on the switch.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct order of steps is: 1. Create and enter interface configuration mode for the logical port-channel interface. 2. Configure switchport trunking encapsulation, trunk mode, and allowed VLANs on the port-channel interface. 3. Select the range of physical member interfaces connected to the WLC distribution ports. 4. Bind the physical member interfaces to the port-channel using channel-group mode on.

The correct operational sequence begins by creating the logical port-channel interface and setting its trunking and VLAN parameters. Next, the network engineer selects the physical switch interfaces connected to the controller's distribution ports and assigns them to the channel group using 'mode on'. Static aggregation is required because AireOS WLCs use unnegotiated bundle distribution across all active ports.

Step-by-Step Solution

Create the logical port-channel interface on the Catalyst switch.

The port-channel interface (e.g., interface Port-channel 1) is instantiated.

Establishing the logical bundle interface first provides a central point to apply trunking properties.

Apply 'switchport mode trunk' and allowed VLAN commands to the port-channel interface.

The logical interface is configured as an 802.1Q trunk carrying required WLAN management and data VLANs.

Applying configurations to the port-channel interface prevents port inconsistency errors across member links.

Enter interface range mode for the physical switch ports connecting to the WLC.

Physical ports (e.g., interface range GigabitEthernet1/0/1 - 2) are selected.

Physical interface mode is needed to assign the specific physical links into the aggregated bundle.

Issue the 'channel-group 1 mode on' command on the physical interfaces.

Physical interfaces join the port-channel as static EtherChannel members.

Cisco AireOS Wireless LAN Controllers do not negotiate LACP or PAgP control frames; the switch ports must use static channel mode 'on'.

Key Concept

Switch EtherChannel Configuration Sequence for AireOS WLC Link Aggregation

Estimated Time:1m 30s

Question 398Question →

A network administrator is manually configuring Rapid PVST+ on a Cisco Catalyst switch to act as a secondary root bridge for VLAN 75. The administrator attempts to enter a custom priority value using the `spanning-tree vlan 75 priority <value>` command in global configuration mode. Which priority value will be accepted by Cisco IOS for this command?

28672

28747

30000

32843

Show answer & explanation

Answer: 28672

Answer

The priority value 28672 is accepted because Cisco IOS requires the priority argument in the 'spanning-tree vlan X priority' command to be specified in increments of 4096.

In Rapid PVST+, Cisco switches enforce the 802.1t System ID Extension. The 16-bit Priority field is split into a 4-bit Bridge Priority field and a 12-bit VLAN ID field. Consequently, the user-configurable base bridge priority in the CLI must be an explicit multiple of 4096 (

4096 \times 7 = 28672

). When 28672 is entered, the switch adds VLAN 75 internally to yield a total priority of 28747.

Step-by-Step Solution

Identify the standard requirement for Rapid PVST+ Bridge Priority values in Cisco IOS.

Rapid PVST+ utilizes 802.1t System ID Extension, dividing the 16-bit Bridge Priority field into a 4-bit Priority field and a 12-bit System ID Extension (VLAN ID).

Because the upper 4 bits control the configurable priority, configured values must be multiples of

2^{12} = 4096

Evaluate the CLI input requirements for the command 'spanning-tree vlan 75 priority <value>'.

The CLI argument accepts only base priority increments: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, etc.

The switch software automatically appends the VLAN ID (75) to the base priority to form the actual 16-bit priority carried in BPDUs (

28672 + 75 = 28747

Select the option that represents a valid 4096 multiple.

28672 is equal to

4096 \times 7

, making it a valid configuration parameter.

All other choices represent non-4096 multiples or values resulting from manually pre-adding the VLAN ID.

Key Concept

Rapid PVST+ System ID Extension and Bridge Priority CLI configuration constraints.

Question 399Question →

An IT technician is preparing a newly racked Cisco Catalyst switch to connect corporate workstations. The technician needs to create VLAN 15 named FIN_DEPT and assign interface GigabitEthernet0/5 to this VLAN as a static access port while explicitly disabling Dynamic Trunking Protocol (DTP) frame negotiation. Which sequence of Cisco IOS commands correctly accomplishes this configuration?

vlan 15
name FIN_DEPT
exit
interface GigabitEthernet0/5
switchport mode access
switchport access vlan 15
switchport nonegotiate

vlan 15
name FIN_DEPT
exit
interface GigabitEthernet0/5
switchport mode dynamic desirable
switchport access vlan 15

vlan 15
name FIN_DEPT
exit
interface GigabitEthernet0/5
switchport trunk native vlan 15

vlan 15
name FIN_DEPT
exit
interface GigabitEthernet0/5
switchport access vlan 15
switchport mode trunk

Show answer & explanation

Answer: vlan 15
name FIN_DEPT
exit
interface GigabitEthernet0/5
switchport mode access
switchport access vlan 15
switchport nonegotiate

Answer

The correct command sequence creates VLAN 15 named FIN_DEPT, configures the interface with 'switchport mode access' to force static access mode, assigns it to VLAN 15 with 'switchport access vlan 15', and disables DTP frame negotiation using 'switchport nonegotiate'.

The correct command sequence creates VLAN 15 named FIN_DEPT in global configuration mode, enters interface mode for GigabitEthernet0/5, sets the operational mode to static access using 'switchport mode access', assigns it to VLAN 15 using 'switchport access vlan 15', and turns off Dynamic Trunking Protocol frame generation with 'switchport nonegotiate'.

Step-by-Step Solution

Create and name the VLAN in global configuration mode

VLAN 15 is created and assigned the name FIN_DEPT.

VLANs must exist in the switch VLAN database to forward traffic properly for assigned access interfaces.

Enter interface configuration mode and set the switchport mode

Interface GigabitEthernet0/5 is statically set to access mode via 'switchport mode access'.

Static access mode prevents the port from dynamically negotiating trunking.

Assign the interface to VLAN 15 and disable DTP negotiation

The port is assigned to VLAN 15 with 'switchport access vlan 15' and DTP negotiation is disabled with 'switchport nonegotiate'.

This completes static access port setup and hardens the port against unauthorized trunk negotiation.

Key Concept

VLAN Creation, Access Port Assignment, and DTP Hardening

Question 400Question →

A network administrator needs to create VLAN 60 named DEV_TEAM on a Cisco Catalyst switch and configure interface GigabitEthernet0/15 as a static access port assigned to that VLAN. Place the Cisco IOS CLI commands in the correct chronological sequence to perform this configuration starting from Privileged EXEC mode.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct operational sequence is: configure terminal -> vlan 60 -> name DEV_TEAM -> interface GigabitEthernet0/15 -> switchport mode access -> switchport access vlan 60.

To configure a new VLAN with a specific name and assign a port to it, the process must follow Cisco IOS hierarchy: first enter global configuration mode ('configure terminal'), instantiate the VLAN and enter VLAN sub-mode ('vlan 60'), set the VLAN name ('name DEV_TEAM'), enter interface sub-mode ('interface GigabitEthernet0/15'), set the port mode ('switchport mode access'), and assign the access VLAN ('switchport access vlan 60').

Step-by-Step Solution

Enter Global Configuration mode

Switch prompt changes to Switch(config)#

VLAN creation commands are global configuration commands and cannot be executed directly from Privileged EXEC mode.

Create VLAN 60

Switch prompt changes to Switch(config-vlan)#

Executes VLAN creation and switches context to VLAN configuration mode.

Name the VLAN DEV_TEAM

VLAN 60 is labeled with the name DEV_TEAM

The 'name' command must be executed within VLAN configuration context.

Select interface GigabitEthernet0/15

Switch prompt changes to Switch(config-if)#

Interface-specific settings require moving into interface configuration sub-mode.

Set port operational mode to access

DTP dynamic trunking negotiation is disabled for active access mode

Configuring 'switchport mode access' ensures the interface acts purely as a static access link.

Assign the port to VLAN 60

GigabitEthernet0/15 becomes an active access member of VLAN 60

Binds untagged ingress/egress frames on GigabitEthernet0/15 to broadcast domain VLAN 60.

Key Concept

Cisco IOS sequence for creating VLANs, configuring VLAN names, and assigning static access interfaces

PreviousPage 20 / 20

Network Access

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept