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Soru 101Soru →

A switch port running classic IEEE 802.1D Spanning Tree Protocol (STP) detects link UP on a non-PortFast access interface. Place the 802.1D STP port states in the exact chronological sequence through which the interface transitions from link initialization to fully active frame processing.

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The correct operational sequence of classic 802.1D STP port states from link bring-up to active data transmission is: Blocking State -> Listening State -> Learning State -> Forwarding State.
Under standard IEEE 802.1D Spanning Tree Protocol, non-PortFast interfaces progress strictly through Blocking, Listening, Learning, and Forwarding states. The Blocking state prevents loops upon initialization; Listening (15s Forward Delay) processes BPDUs and determines port roles; Learning (15s Forward Delay) builds MAC address tables from source MACs; and Forwarding permits normal data payload processing.

Adım Adım Çözüm

1
Identify the initial non-functional state upon physical link activation.
The port initializes in the Blocking State.
STP ports default to Blocking to discard user data frames and prevent switching loops while listening for control frames (BPDUs).
2
Identify the state where STP role determination occurs.
The port moves into the Listening State.
During the Listening phase (lasting 15 seconds by default), the switch processes and sends BPDUs to determine Root Bridge and port roles without populating MAC tables or forwarding data frames.
3
Identify the state where address table construction begins.
The port transitions to the Learning State.
After the first 15-second Forward Delay timer expires, the port enters Learning where it examines source MAC addresses of incoming frames to build the MAC address table, but still drops payload data frames.
4
Identify the final fully functional state.
The port enters the Forwarding State.
After the second 15-second Forward Delay timer expires (total 30 seconds convergence), the port transitions to Forwarding where it actively forwards and receives user data frames.

Anahtar Kavram

IEEE 802.1D STP Sequential Port State Transitions
Tahmini Süre:1m 15s
Soru 102Soru →

A network administrator needs to create a new Wireless LAN (WLAN) on a Cisco Wireless LAN Controller (WLC) using the GUI to allow client connectivity. Arrange the steps required to configure and activate the new WLAN in the correct sequential order.

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The correct order to create and activate a WLAN via the Cisco WLC GUI is: 1) Navigate to the WLANs tab and select 'Create New', 2) Define the Profile Name, SSID, and mapped Interface under the General tab, 3) Select Layer 2 security settings under the Security tab, and 4) Select the Status checkbox under the General tab and click Apply to enable client connections.
When configuring a WLAN via the Cisco WLC GUI, the administrator must first create the new WLAN entry from the WLANs menu. Next, the Profile Name, SSID, and Interface mapping are set under the General tab. After that, authentication methods (such as PSK or 802.1X) are selected under the Security tab. Finally, the Status checkbox under the General tab is enabled and applied to begin broadcasting the network to client devices.

Adım Adım Çözüm

1
Initiate WLAN creation in WLC GUI
WLAN creation page is displayed
Selecting 'Create New' under the WLANs menu starts the creation process.
2
Configure basic parameters and interface mapping
WLAN identity and network binding are defined
Setting the Profile Name, SSID, and Interface/Interface Group binds the WLAN to the correct network segment.
3
Configure security options
WLAN security and authentication parameters are set
Security parameters under the Security tab define how clients authenticate and encrypt traffic.
4
Enable WLAN Status and apply changes
WLAN becomes active and broadcasts the SSID to clients
Checking the Status box enables the WLAN profile on the controller.

Anahtar Kavram

WLC GUI WLAN Configuration Sequence
Tahmini Süre:1m 0s
Soru 103Soru →

A Cisco Catalyst switch receives an ingress Ethernet frame on interface GigabitEthernet0/1 assigned to VLAN 10. The frame contains a source MAC address that does not currently exist in the MAC address table and a destination MAC address that is already registered on interface GigabitEthernet0/2 in VLAN 10. Arrange the switch processing actions in the correct chronological sequence from initial frame reception to egress forwarding.

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The correct sequence is: (1) Frame reception and header parsing on GigabitEthernet0/1, (2) Learning the source MAC address by adding an entry for GigabitEthernet0/1 in VLAN 10, (3) Looking up the destination MAC address in the MAC address table, and (4) Forwarding the unicast frame out GigabitEthernet0/2.
When a switch receives a frame, it follows a strict sequence of operations: first receiving and parsing the header, then learning the source MAC address (adding/updating the MAC table entry for the ingress port), looking up the destination MAC address in the table, and finally forwarding the frame out the designated destination interface.

Adım Adım Çözüm

1
Analyze frame ingress
The switch receives the frame on interface GigabitEthernet0/1, identifying VLAN 10, source MAC, and destination MAC.
Header parsing is the initial hardware step when a frame enters a switchport.
2
Process source MAC learning
The switch adds a dynamic entry mapping the unknown source MAC address to GigabitEthernet0/1 in VLAN 10.
Cisco switches perform Layer 2 source MAC learning before evaluating destination forwarding.
3
Perform destination lookup
The MAC address table search matches the destination MAC to interface GigabitEthernet0/2.
Destination address matching dictates whether a frame is forwarded to a single port or flooded.
4
Execute frame forwarding
The frame is forwarded directly out GigabitEthernet0/2.
Known unicast frames are forwarded solely out the egress port specified in the MAC table.

Anahtar Kavram

Layer 2 Switch Ingress Processing & MAC Address Table Operation
Soru 104Soru →

A Cisco switch running Rapid PVST+ receives BPDUs on multiple interfaces from neighboring switches leading toward the Root Bridge. Place the tie-breaking criteria in the exact sequential order (from first evaluated to last evaluated) that the switch processes to elect its single Root Port.

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The correct sequential order for Rapid PVST+ Root Port election tie-breakers is: 1. Lowest cumulative Root Path Cost to the Root Bridge, 2. Lowest Designated (upstream neighbor) Bridge ID (BID), 3. Lowest Designated (upstream neighbor) Port Priority, 4. Lowest Designated (upstream neighbor) Port Number, 5. Lowest local (receiving) Port ID on the evaluating switch.
When electing a Root Port, Rapid PVST+ follows a strict hierarchical evaluation of BPDU criteria: 1) Lowest cumulative path cost to the root bridge, 2) Lowest transmitting neighbor Bridge ID, 3) Lowest transmitting neighbor port priority, 4) Lowest transmitting neighbor port number, and 5) Lowest local receiving port ID. Local interface parameters are evaluated last because upstream BPDU parameters take precedence.

Adım Adım Çözüm

1
Evaluate the cumulative path cost
The switch calculates the sum of port costs along the path to the Root Bridge. The port receiving the lowest total cost becomes the Root Port candidate.
Path efficiency to the Root Bridge is the primary metric for spanning-tree forwarding path selection.
2
Compare upstream neighbor Bridge IDs
If cumulative path costs are equal, compare the sending switch's Bridge ID (Bridge Priority + System ID Extension + MAC Address).
Paths connected to a superior upstream bridge take precedence.
3
Compare upstream neighbor Port Priority
If BPDUs are received from the same upstream neighbor over parallel links, compare the neighbor's Port Priority value (default 128).
Upstream administrators can influence downstream port selection by modifying port priority on the transmitting end.
4
Compare upstream neighbor Port Number
If neighbor port priorities match, compare the numerical interface index of the neighbor's transmitting interface (e.g., GigabitEthernet0/1 vs GigabitEthernet0/2).
Lower interface numbers on the neighbor take precedence when priorities are equal.
5
Compare local receiving Port ID
If all upstream BPDU fields are identical (such as when connected to an shared medium like an unmanaged hub), evaluate the local receiving switch's Port ID (Priority then Port Number).
The local receiving port ID serves as the absolute final tie-breaker because no upstream BPDU fields can differentiate the paths.

Anahtar Kavram

Rapid PVST+ Root Port Election Sequence
Soru 105Soru →

A network technician needs to configure a new VLAN and assign a switch interface to it on a Cisco Catalyst switch. Arrange the following Cisco IOS commands in the correct sequence to create VLAN 20 and configure interface GigabitEthernet0/2 as a static access port in VLAN 20, starting from global configuration mode.

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The correct operational sequence from global configuration mode is first creating the VLAN with 'vlan 20', entering interface configuration mode with 'interface gigabitethernet 0/2', setting the operational mode to access with 'switchport mode access', and finally assigning the interface to the VLAN with 'switchport access vlan 20'.
The proper administrative workflow in Cisco IOS requires creating or defining the VLAN in global configuration mode, entering the target interface configuration context, defining the administrative port state as an access port using 'switchport mode access', and specifying the access VLAN membership using 'switchport access vlan 20'.

Adım Adım Çözüm

1
Create VLAN 20 in global configuration mode.
Executes 'vlan 20' to instantiate the VLAN and enter config-vlan submode.
Creating the VLAN first ensures the VLAN exists in the Layer 2 database.
2
Enter target interface configuration mode.
Executes 'interface gigabitethernet 0/2' to transition to config-if submode.
Interface parameters must be modified within the specific interface context.
3
Configure the port as a Layer 2 access port.
Executes 'switchport mode access' to turn off DTP negotiation for trunking.
Setting the administrative mode to access enforces single-VLAN membership.
4
Assign the port to VLAN 20.
Executes 'switchport access vlan 20' to bind interface traffic to VLAN 20.
This command places untagged frames received on GigabitEthernet0/2 into VLAN 20.

Anahtar Kavram

Cisco IOS VLAN configuration and interface access mode sequence
Tahmini Süre:45s
Soru 106Soru →

Place the tie-breaker criteria used by a non-root switch running Rapid PVST+ to select its Root Port in the correct order, from first evaluated (highest priority) to last evaluated (lowest priority).

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The correct evaluation sequence for electing a Root Port is: 1) Lowest cumulative root path cost, 2) Lowest sender Bridge ID, 3) Lowest sender port priority, and 4) Lowest sender port number.
When a non-root switch receives BPDUs across multiple active interfaces, it runs the Rapid PVST+ Root Port election process in a strict sequential order: first, it selects the port with the lowest cumulative root path cost. If path costs are equal, it compares the neighbor Bridge IDs and picks the lowest. If multiple connections lead to the same neighboring switch, it compares the sender's port priority, and finally breaks any remaining tie using the sender's lowest port number.

Adım Adım Çözüm

1
Identify the primary metric for Root Port selection in Rapid PVST+.
The switch evaluates the total path cost (cumulative root path cost) to reach the Root Bridge.
STP prioritizes forwarding traffic across the most direct/highest bandwidth path available.
2
Determine the tie-breaker when path costs from multiple interfaces are equal.
The switch evaluates the Bridge ID of the neighboring (sender) switches.
If equal-cost paths exist through different upstream switches, preferring the neighbor with the lower BID ensures determinism.
3
Determine the tie-breaker when parallel links connect to the exact same upstream neighbor switch.
The switch compares the Port Priority value advertised by the sending switch interface.
Port priority is configured on the upstream switch to influence path selection on downstream switches.
4
Identify the final tie-breaker when all upstream port priorities are identical.
The switch selects the link connected to the lowest physical port number on the upstream sender switch.
This guarantees a deterministic, unambiguous decision even when default configurations are unchanged.

Anahtar Kavram

Rapid PVST+ Root Port Election Tie-Breaker Decision Tree
Soru 107Soru →

A network engineer needs to configure a routed (Layer 3) EtherChannel bundle on a Cisco Catalyst switch using LACP active mode on physical interfaces GigabitEthernet0/1 and GigabitEthernet0/2, assigning the IP address 10.1.1.1/30 to the logical channel. In what sequential order should the configuration steps be executed on the switch CLI?

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The correct execution order is: 1) Enter interface range configuration mode for GigabitEthernet0/1 - 2, 2) Execute 'no switchport' on member interfaces to convert them to Layer 3, 3) Issue 'channel-group 10 mode active' to initiate LACP, 4) Access 'interface Port-channel 10' and assign IP address 10.1.1.1 255.255.255.252.
Configuring a Layer 3 LACP EtherChannel follows a precise sequence: first select member physical interfaces (`interface range`), convert them from Layer 2 to Layer 3 (`no switchport`), assign them to the channel group with LACP negotiation (`channel-group 10 mode active`), and finally configure the IP address on the logical bundle (`interface Port-channel 10`).

Adım Adım Çözüm

1
Select member physical interfaces using `interface range GigabitEthernet0/1 - 2`.
Enters range interface configuration mode context `(config-if-range)#`.
Allows simultaneous configuration of all member links intended for the EtherChannel bundle.
2
Execute `no switchport` on physical member interfaces.
Disables Layer 2 switchport operation on GigabitEthernet0/1 and GigabitEthernet0/2.
Layer 3 EtherChannels require member interfaces to operate as routed ports prior to group assignment so that Port-Channel 10 is dynamically spawned as a Layer 3 interface.
3
Execute `channel-group 10 mode active`.
Creates logical interface Port-channel 10 and enables LACP active negotiation on member ports.
The 'active' keyword configures LACP to actively send LACP packets to negotiate the channel with the peer device.
4
Enter `interface Port-channel 10` and assign `ip address 10.1.1.1 255.255.255.252`.
Assigns the IPv4 protocol configuration to the logical routed bundle.
In a routed EtherChannel, IP addresses are configured exclusively on the logical Port-channel interface, not on physical member links.

Anahtar Kavram

Layer 3 EtherChannel CLI Configuration and LACP Active Mode Negotiation Sequence
Soru 108Soru →

A network administrator needs to manually provision a new VLAN for guest wireless traffic (VLAN 88 named GUEST_WIFI) and configure switch port GigabitEthernet1/0/22 as a dedicated access port in this VLAN on a Cisco Catalyst switch. Place the Cisco IOS CLI commands in the correct administrative order of execution starting from global configuration mode.

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The correct operational sequence begins with defining VLAN 88 in global configuration mode ('vlan 88'), naming the VLAN ('name GUEST_WIFI'), navigating to the target port ('interface gigabitethernet 1/0/22'), setting static access mode ('switchport mode access'), and assigning the access VLAN membership ('switchport access vlan 88').
Cisco IOS command syntax requires configuring global parameters (VLAN ID and name in VLAN subconfiguration mode) prior to entering interface subconfiguration mode to establish static access mode and assign the access VLAN membership.

Adım Adım Çözüm

1
Execute 'vlan 88' in global configuration mode (Switch(config)#).
Initializes VLAN 88 in the local VLAN database and shifts prompt context to Switch(config-vlan)#.
Defining the VLAN ID is required to instantiate the subconfiguration context for setting VLAN attributes.
2
Execute 'name GUEST_WIFI' within VLAN subconfiguration mode.
Assigns the label 'GUEST_WIFI' to VLAN 88.
The 'name' command is a VLAN subconfiguration command that can only be issued under the Switch(config-vlan)# prompt.
3
Navigate to interface configuration mode via 'interface gigabitethernet 1/0/22'.
Changes prompt context to Switch(config-if)# for GigabitEthernet1/0/22.
Port configuration commands require entering the interface-specific configuration mode from global configuration mode.
4
Execute 'switchport mode access' on the interface.
Disables Dynamic Trunking Protocol (DTP) negotiation and locks the port into permanent access mode.
Explicitly enforcing access mode prevents trunk negotiation vulnerabilities before binding the port to a VLAN.
5
Execute 'switchport access vlan 88' on the interface.
Assigns untagged frames received on GigabitEthernet1/0/22 to broadcast domain VLAN 88.
Maps the physical interface to the configured broadcast domain.

Anahtar Kavram

Cisco IOS CLI prompt hierarchy for VLAN creation, naming, static access port configuration, and VLAN membership assignment
Soru 109Soru →

A network administrator connects a PC to a Cisco switch access port configured with standard IEEE 802.1D Spanning Tree Protocol (STP) without PortFast enabled. Place the STP port states in the correct chronological order from the moment the physical link comes up until the port actively processes end-user network traffic.

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Cevap

The correct chronological order of 802.1D STP port state transitions from link initiation to active forwarding is: Blocking State, Listening State, Learning State, and Forwarding State.
Under standard IEEE 802.1D Spanning Tree Protocol, an access interface without PortFast undergoes a 30-second convergence delay through specific sequential states: Blocking state (loop prevention), Listening state (15s to exchange BPDUs and determine port roles), Learning state (15s to populate MAC tables), and finally Forwarding state (active user traffic processing).

Adım Adım Çözüm

1
Identify the starting state when the physical interface transitions to up.
The port initializes in the Blocking state to prevent layer 2 loops.
Before topology calculations occur, all data frame processing and MAC learning are disabled.
2
Determine the state transition after the initial blocking evaluation.
The port moves to the Listening state for the duration of the Forward Delay timer (15 seconds).
In Listening, the switch participates in BPDUs exchange to determine spanning-tree topology roles without learning MAC addresses or forwarding frames.
3
Determine the state transition after port roles are settled.
The port enters the Learning state for a second Forward Delay interval (15 seconds).
In Learning, the port populates its MAC address table from frame headers to avoid excessive unicast flooding once forwarding begins.
4
Identify the final operational state.
The port transitions to the Forwarding state after completing both Forward Delay periods (30 seconds total convergence delay).
The port is now permitted to actively forward user data plane frames.

Anahtar Kavram

IEEE 802.1D STP Port State Transition Sequence
Tahmini Süre:1m 0s
Soru 110Soru →

A Cisco router receives an IP packet destined for host 172.16.35.67172.16.35.67. The routing table contains multiple candidate routes that match this destination IP address. Place the routing decision criteria in the correct order of precedence used by the router to make its forwarding decision, from first evaluated (highest precedence) at the top to last evaluated (lowest precedence) at the bottom.

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The correct sequence of router forwarding decision logic criteria from highest to lowest precedence is: 1) Longest Prefix Match, 2) Lowest Administrative Distance, 3) Lowest Metric, and 4) Equal-Cost Load Balancing.
When forwarding an IP packet, a Cisco router evaluates candidate routes in a strict multi-tier hierarchy. First, Longest Prefix Match (LPM) determines the best route by selecting the entry with the most specific subnet mask. Second, if multiple routes match with the exact same subnet mask length, the router compares Administrative Distance (AD) to select the most trustworthy route source. Third, if routes share the exact same prefix length and come from the same routing protocol, the router selects the path with the lowest metric. Finally, if prefix length, AD, and metric are all identical, equal-cost load balancing is applied.

Adım Adım Çözüm

1
Evaluate mask length specificity (Longest Prefix Match).
The router compares the destination address against all routing table entries and isolates candidate routes matching the highest number of left-to-right network bits (longest subnet mask).
Longest Prefix Match is the primary decision rule in IP packet forwarding and overrides AD and metric.
2
Compare Administrative Distance (AD) for identical prefix lengths.
If candidate routes share the exact same prefix length (e.g., two /24/24 routes), the router compares route sources and selects the one with the lowest AD value.
Administrative Distance defines the believability or trustworthiness of the route source.
3
Compare routing protocol Metric for identical prefix length and route source.
If multiple candidate routes share the exact same prefix length and originate from the same routing protocol (same AD), the router selects the path with the lowest metric value.
Metric measures the cost or desirability of a specific path within a routing protocol domain.
4
Execute Equal-Cost Multi-Path (ECMP) load balancing.
If candidate routes for the exact same prefix length have identical AD and metric values, the router installs multiple paths in the Forwarding Information Base (FIB) and distributes traffic across them.
Equal-cost load balancing optimizes link usage when multiple best paths exist.

Anahtar Kavram

Router Forwarding Decision Hierarchy (LPM -> AD -> Metric -> ECMP)
Tahmini Süre:2m 0s
Soru 111Soru →

A network administrator needs to manually configure a floating static route on a Cisco IOS router to serve as a backup path. Arrange the required command components in the correct sequential order from left to right as typed in the CLI.

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Cevap

The correct sequence for configuring a floating IPv4 static route in Cisco IOS is: `ip route` keyword, destination network address, subnet mask, next-hop IPv4 address (or exit interface), and administrative distance.
The standard Cisco IOS syntax for configuring an IPv4 static route is `ip route <destination-prefix> <subnet-mask> {ip-address | exit-interface} [distance]`. Placing `ip route` first, followed by the destination network prefix, subnet mask, next-hop IP address, and finally the administrative distance creates a valid floating static route.

Adım Adım Çözüm

1
Identify the global configuration command mode keyword
Start with `ip route`.
Cisco IOS requires the keyword `ip route` to initiate an IPv4 static route entry.
2
Specify target destination network parameters
Provide the destination network IP (`192.168.20.0`) followed by its subnet mask (`255.255.255.0`).
The router must know which destination address block this route applies to.
3
Define forwarding path
Specify the next-hop IP address (`10.1.1.2`) or local exit interface.
The router requires explicit instructions on where to send matching packets.
4
Configure administrative distance for backup behavior
Append an administrative distance value greater than the primary protocol's AD (e.g., `130`).
Setting an AD higher than the primary route (such as OSPF AD 110) ensures the static route remains floating until the primary fails.

Anahtar Kavram

Cisco IOS IPv4 Static Route Command Syntax and Floating Route Configuration
Soru 112Soru →

In Cisco Rapid PVST+, a switch constructs an 8-byte (64-bit) Bridge ID (BID) for each VLAN instance to participate in Root Bridge election. Arrange the three components of the Rapid PVST+ Bridge ID in order from most significant bits (leftmost) to least significant bits (rightmost).

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Cevap

The correct sequence from most significant bits to least significant bits is: 4-bit Bridge Priority, 12-bit System ID Extension (VLAN ID), and 48-bit MAC Address.
The 8-byte (64-bit) Rapid PVST+ Bridge ID is ordered from most significant to least significant bits as follows: 4-bit Bridge Priority (bits 63–60), 12-bit System ID Extension representing the VLAN ID (bits 59–48), and the 48-bit switch MAC Address (bits 47–0).

Adım Adım Çözüm

1
Examine the 2-byte (16-bit) Priority field structure in the Rapid PVST+ Bridge ID.
The upper 4 bits represent the configurable Bridge Priority, making them the most significant bits of the entire 64-bit Bridge ID.
This layout ensures that user-defined priority configurations take precedence over VLAN IDs and MAC addresses.
2
Identify the remaining sub-field of the 2-byte Priority field.
The lower 12 bits of the Priority field carry the System ID Extension (VLAN ID).
Carrying the VLAN ID within these 12 bits allows Rapid PVST+ to maintain unique Bridge IDs per VLAN without requiring separate MAC addresses for each instance.
3
Identify the final 6 bytes (48 bits) of the Bridge ID.
The lowest 48 bits consist of the switch's burned-in MAC address.
The MAC address serves as the final tie-breaker during Root Bridge election when Bridge Priority and VLAN ID values are equal.

Anahtar Kavram

Rapid PVST+ Bridge ID (BID) Structure and System ID Extension
Soru 113Soru →

A Cisco switch operating with Rapid PVST+ receives multiple BPDUs across several redundant trunk links connecting toward the Root Bridge. To elect its single Root Port for a given VLAN instance, the switch executes a standardized four-step tie-breaking sequence to select the best path.

In what chronological sequence does the switch evaluate these criteria, starting from the first criterion evaluated (highest precedence) to the final criterion evaluated (lowest precedence)?

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Cevap

The correct sequence for electing a Root Port in Rapid PVST+ evaluates: 1) Lowest cumulative Root Path Cost, 2) Lowest Sender Bridge ID, 3) Lowest Sender Port ID, and 4) Lowest Local Port ID.
In Rapid PVST+ (and standard 802.1D/802.1w STP), a non-root switch selects its single Root Port by comparing BPDU criteria in strict order: first, the lowest cumulative Root Path Cost; second, the lowest Sender (Designated) Bridge ID; third, the lowest Sender (Designated) Port ID; and fourth, the lowest Local (Receiver) Port ID.

Adım Adım Çözüm

1
Evaluate candidate path metrics toward the elected Root Bridge.
The interface receiving the BPDU with the lowest cumulative Root Path Cost is preferred.
STP path selection prioritizes optimal forwarding efficiency to the Root Bridge.
2
Compare upstream neighbor identities if path costs match.
The interface connected to the neighbor switch possessing the lowest Bridge ID (Priority + MAC address) is chosen.
Sender BID serves as the primary tie-breaker when multiple paths yield identical path costs.
3
Compare upstream neighbor port identifiers if connecting to the same neighbor switch across parallel links.
The interface receiving BPDUs from the lower Sender Port ID (Port Priority + Port Index) is selected.
The upstream switch's Designated Port ID breaks ties when path cost and neighbor BID are identical.
4
Evaluate local receiving interface identifiers as the final tie-breaker.
The local port with the lowest internal Port ID (Port Priority + Port Number) becomes the Root Port.
When all external BPDU parameters match, the local switch uses its own port numerical priority as the final determinant.

Anahtar Kavram

Rapid PVST+ Root Port Decision Sequence
Soru 114Soru →

A network engineer is configuring a routed (Layer 3) EtherChannel bundle on a Cisco switch using LACP active mode across physical interfaces GigabitEthernet 0/1 and 0/2. Place the CLI configuration commands in the correct sequential order from initial interface selection to final Layer 3 IP address assignment.

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Cevap

The correct configuration sequence is: enter physical interface range mode ('interface range GigabitEthernet 0/1 - 2'), convert physical member links to Layer 3 ('no switchport'), configure LACP mode ('channel-group 1 mode active'), enter port-channel interface mode ('interface Port-channel 1'), and assign the IP address ('ip address 10.1.1.1 255.255.255.252').
To deploy a routed (Layer 3) EtherChannel using LACP, the physical interfaces must first be selected ('interface range GigabitEthernet 0/1 - 2') and explicitly converted to routed ports ('no switchport'). Next, the LACP active negotiation mode is configured ('channel-group 1 mode active'), creating the logical bundle. Finally, the administrator navigates into the port-channel interface ('interface Port-channel 1') and assigns the IP address ('ip address 10.1.1.1 255.255.255.252').

Adım Adım Çözüm

1
Select physical member interfaces
Enters interface range configuration mode for GigabitEthernet 0/1 and 0/2.
Configuration changes must be applied across both physical candidate interfaces simultaneously.
2
Disable Layer 2 functionality on member interfaces
Executes 'no switchport' on member interfaces.
Member interfaces must match the Layer 3 operation requirement before joining a routed EtherChannel.
3
Configure channel-group and LACP mode
Executes 'channel-group 1 mode active'.
Binds physical interfaces to channel-group 1 and actively initiates LACP negotiation.
4
Navigate to the logical port-channel interface
Enters 'interface Port-channel 1'.
Enables logical interface parameter configuration.
5
Assign Layer 3 IPv4 address
Executes 'ip address 10.1.1.1 255.255.255.252'.
Layer 3 IP addresses are configured directly on the port-channel interface, not on the individual physical member interfaces.

Anahtar Kavram

Layer 3 EtherChannel LACP Configuration Sequence
Tahmini Süre:1m 30s
Soru 115Soru →

Host-X sends an Ethernet frame destined for Host-Y through a Cisco Catalyst switch. The switch receives the frame on interface FastEthernet0/2. At the time of arrival, Host-X's source MAC address is not present in the switch MAC address table, while Host-Y's destination MAC address is already mapped to FastEthernet0/8. Place the internal processing steps performed by the Layer 2 switch in the correct chronological sequence from first to last.

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Cevap

The correct chronological sequence begins with receiving the frame on FastEthernet0/2, followed by learning the source MAC address (MAC-X), performing a table lookup for the destination MAC address (MAC-Y), matching MAC-Y to FastEthernet0/8, and finally forwarding the frame solely out interface FastEthernet0/8.
The correct order follows standard Cisco Layer 2 switching logic: 1) Ingress frame reception on interface FastEthernet0/2; 2) Source MAC address inspection and MAC table entry creation for FastEthernet0/2; 3) Destination MAC address table lookup; 4) Identification of egress port FastEthernet0/8; 5) Unicast transmission out FastEthernet0/8.

Adım Adım Çözüm

1
Receive Ingress Frame
The switch physical port FastEthernet0/2 accepts the frame header containing source MAC-X and destination MAC-Y.
Layer 2 processing requires the physical frame to enter an ingress interface first.
2
Source MAC Learning
Source MAC-X is mapped to FastEthernet0/2 in the switch MAC address table.
Switches update or populate their CAM/MAC table based on ingress source MAC addresses.
3
Destination MAC Lookup
The switch queries the MAC address table for destination MAC-Y.
The switch needs to decide whether to flood or unicast-forward the ingress frame based on destination MAC state.
4
Match Egress Port
The lookup resolves MAC-Y to interface FastEthernet0/8.
A matching entry prevents unknown unicast flooding.
5
Unicast Frame Forwarding
The frame is transmitted directly out FastEthernet0/8.
Known unicast destination entries result in single-port forwarding.

Anahtar Kavram

Layer 2 Ethernet Switching Process and MAC Address Table Learning and Forwarding Logic
Soru 116Soru →

A Cisco router receives an Ethernet frame containing an IPv4 packet destined for a remote host. Place the router's forwarding decision steps in the exact chronological order in which they are evaluated from initial packet reception to egress frame transmission.

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The correct sequence starts with extracting the destination IPv4 address, performing the Longest Prefix Match search, resolving ties using Administrative Distance, comparing metrics for remaining identical protocol routes, and finally rewriting Layer 2 headers to forward out the exit interface.
The router processes forwarding logic sequentially: destination IP extraction happens first, followed by selecting candidate routes based strictly on Longest Prefix Match (LPM). If multiple routes share the identical prefix length, Administrative Distance (AD) determines the trusted protocol source. If AD is also equal, metric cost breaks the tie. Once the best path is chosen, Layer 2 header rewriting and egress transmission occur as the final step.

Adım Adım Çözüm

1
Examine incoming packet header.
Destination IP address is retrieved for routing lookup.
The router requires the destination address to query the routing table.
2
Perform Longest Prefix Match (LPM) evaluation.
Routing table entries with the highest number of matching network bits are selected.
LPM is always the primary criterion for route selection, overriding AD and metric.
3
Evaluate Administrative Distance (AD).
The route from the routing protocol with the lowest AD is selected if prefix lengths match.
AD measures route source trustworthiness.
4
Evaluate metric cost.
The route with the lowest metric cost is chosen if prefix lengths and AD are equal.
Metric measures path cost within a single routing protocol instance.
5
Perform egress frame encapsulation and transmission.
New source and destination MAC addresses are populated, ARP/ND is queried if necessary, and the frame is transmitted out the exit interface.
Layer 2 rewrites are required for adjacent next-hop framing.

Anahtar Kavram

Router Forwarding Decision Logic Priority (LPM -> AD -> Metric -> L2 Encapsulation)
Soru 117Soru →

A Cisco switch receives an Ethernet frame on a port configured as an 802.1Q trunk link. In what sequential order does the switch process this incoming frame from initial ingress parsing to its final forwarding decision?

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The correct sequence begins with inspecting the ingress frame header for an 802.1Q tag, assigning the VLAN ID based on tag presence or native VLAN configuration, checking the VLAN against the allowed VLAN list, and finally forwarding or dropping the frame.
When a frame arrives on an 802.1Q trunk interface, the switch performs ingress processing in a strict order: First, it examines the Ethernet header to detect whether an 802.1Q tag (EtherType 0x8100) is present. Second, it determines the internal VLAN ID—reading the 12-bit VLAN ID for tagged frames or mapping untagged frames to the interface's configured native VLAN. Third, it checks whether that VLAN ID is included in the interface's allowed VLAN list. Fourth, if the VLAN is permitted, the switch looks up the MAC table and forwards the frame to destination ports in that VLAN; if the VLAN is disallowed, the frame is dropped.

Adım Adım Çözüm

1
Parse frame header for 802.1Q tag
Determines if an 802.1Q EtherType (0x8100) and 4-byte tag exist within the frame.
The switch must identify encapsulation formatting before reading VLAN metadata.
2
Assign internal VLAN ID
Tagged frames are assigned the 12-bit VLAN ID from the tag; untagged frames are assigned to the port's native VLAN.
All ingress frames inside an 802.1Q switch must be mapped to a specific internal VLAN context.
3
Verify allowed VLAN status
The target VLAN ID is checked against the list defined by 'switchport trunk allowed vlan'.
Filtering rules must confirm that the trunk interface allows traffic for that specific VLAN.
4
Execute switching decision
The frame is switched toward matching destination interfaces or dropped if the VLAN is pruned.
The MAC address table lookup and allowed VLAN check dictate final egress behavior.

Anahtar Kavram

802.1Q Ingress Frame Processing Logic
Tahmini Süre:1m 30s
Soru 118Soru →

A network engineer is tasked with deploying a new WPA2-Enterprise wireless network on a Cisco Wireless LAN Controller (WLC) using the web GUI. The WLAN must enforce 802.1X authentication via an external RADIUS server and support dynamic VLAN assignment using AAA override. What is the correct chronological sequence of steps to configure this WLAN on the WLC GUI from initial creation to feature enablement?

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The correct sequence for configuring a WPA2-Enterprise WLAN with AAA Override on a Cisco WLC GUI is: 1) Create New WLAN (define Profile Name/SSID), 2) Set Interface and Enable Status under General tab, 3) Set WPA2-AES and 802.1X under Security > Layer 2 tab, 4) Select RADIUS Server under Security > AAA Servers tab, and 5) Enable Allow AAA Override under Advanced tab.
The correct procedural order follows standard Cisco WLC administration logic: First, create the WLAN instance with its Profile Name and SSID. Next, configure fundamental interface mapping and admin status on the General tab. Then, configure Layer 2 security for WPA2-Enterprise (802.1X AKM) on the Security > Layer 2 tab. Fourth, link the global RADIUS server under the Security > AAA Servers tab. Finally, navigate to the Advanced tab to enable 'Allow AAA Override' for dynamic VLAN steering.

Adım Adım Çözüm

1
Initiate WLAN creation in WLC GUI
WLAN ID is allocated and initial Profile Name and SSID parameters are bound to the controller database.
You cannot configure specific WLAN sub-tabs until the WLAN instance is created via WLANs > Create New.
2
Configure General tab settings
The WLAN is associated with a distribution interface/interface group and marked administratively enabled.
Binding to an interface provides network pathing for client traffic.
3
Configure Layer 2 Security parameters
Layer 2 security policy is set to WPA2 with AES cipher and 802.1X key management.
Specifying 802.1X key management is a prerequisite for utilizing RADIUS EAP-based client authentication.
4
Bind RADIUS Server under AAA Servers tab
The WLAN targets the specific external RADIUS server for client EAP authentication transactions.
Without selecting an active RADIUS server under AAA Servers, 802.1X authentication requests will fail.
5
Enable AAA Override on Advanced tab
The controller honors RADIUS-returned VLAN attributes (IETF 64, 65, 81) to override the default WLAN interface assignment per user.
AAA Override functionality is disabled by default and resides specifically under the WLAN Advanced settings tab.

Anahtar Kavram

WLC GUI WLAN Configuration Workflow and Feature Navigation
Tahmini Süre:2m 30s
Soru 119Soru →

A Cisco router receives an IPv4 packet on an ingress interface that must be forwarded to a remote destination. Place the router forwarding decision and processing steps in the correct chronological order from packet arrival to egress transmission.

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The correct sequence of router forwarding decision steps is: 1. Extract the destination IPv4 address from the incoming packet header. 2. Search the routing table for matching entries and select the route with the longest prefix mask. 3. Identify the designated exit interface and next-hop IPv4 address from the winning route entry. 4. Query the ARP cache to resolve the Layer 2 MAC address associated with the next-hop IPv4 address. 5. Decrement the IPv4 Time-to-Live (TTL) value, recalculate the header checksum, and encapsulate the packet into a new Layer 2 frame for egress.
When an IPv4 packet arrives on a router interface, the router first parses the IP header to extract the destination IP address. Next, it consults the routing table to find matching network prefixes, selecting the route entry with the longest prefix mask (most specific match). From this winning entry, the router extracts the designated exit interface and next-hop IP. It then queries its ARP cache to discover the destination MAC address corresponding to that next-hop IP. Finally, the router modifies the IP header by decrementing the TTL and recalculating the checksum, encapsulates the packet in a fresh Layer 2 frame with new source/destination MAC addresses, and transmits it out the exit interface.

Adım Adım Çözüm

1
Packet Ingress and IP Parsing
The router receives the Layer 2 frame, verifies the checksum, and extracts the target IPv4 destination address.
The router cannot perform routing table lookups until the destination IP address is identified.
2
Routing Table Lookup via Longest Prefix Match
The router compares the destination IP against entries in the routing table and selects the prefix with the greatest number of matching subnet bits.
Longest Prefix Match (LPM) is the fundamental rule governing packet forwarding lookup in IP routing tables.
3
Forwarding Information Extraction
The winning route entry reveals the egress interface and the next-hop gateway address.
The next-hop address and exit interface are required to prepare the outgoing data link layer frame.
4
Layer 2 Address Resolution
The router looks up the next-hop IPv4 address in its ARP table to find its corresponding MAC address.
Ethernet encapsulation requires a valid destination MAC address for the next-hop device on the multi-access segment.
5
Header Modification and Egress Encapsulation
The router decrements TTL, updates the IP checksum, wraps the packet in a new Layer 2 frame with local source MAC and next-hop destination MAC, and transmits it.
This completes the Layer 3 forwarding operation and sends the packet toward its final destination.

Anahtar Kavram

Router Forwarding Decision Logic and Packet Lifecycle
Soru 120Soru →

A network administrator needs to deploy a new corporate WLAN using WPA2/WPA3 Enterprise authentication on a Cisco AireOS Wireless LAN Controller (WLC) via the web GUI. Arrange the following administrative tasks in the correct sequential order required to successfully configure and activate the WLAN for wireless client connectivity.

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The correct procedural sequence is: 1) Navigate to WLANs > WLANs, select 'Create New' and enter the Profile Name and SSID; 2) On the General tab, map the dynamic interface; 3) Under Security > Layer 2, configure WPA2/WPA3 and 802.1X key management; 4) On the AAA Servers tab, bind the RADIUS authentication server; 5) Return to the General tab to check the Status (Enabled) box and click Apply.
Configuring a WLC WLAN requires a strict logical workflow: basic WLAN instantiation (SSID/Profile Name), interface assignment for VLAN traffic routing, Layer 2 security protocol selection (802.1X), external AAA RADIUS binding, and finally enabling the administrative Status to begin broadcasting the SSID.

Adım Adım Çözüm

1
Initialize WLAN creation in WLC GUI
Defines the WLAN container with unique SSID and Profile Name.
Creating the basic WLAN structure is the mandatory starting point before detailed parameters can be edited.
2
Assign dynamic interface mapping
Associates wireless client traffic to the appropriate VLAN interface.
Setting the interface on the General tab ensures client packets are tagged with the correct VLAN ID upon join.
3
Define Layer 2 security mechanism
Sets authentication mode to 802.1X (WPA2/WPA3 Enterprise).
Configuring 802.1X key management under Security > Layer 2 specifies that external AAA authentication is required.
4
Map external RADIUS authentication server
Binds the globally defined RADIUS server to this specific WLAN under AAA Servers.
The WLC cannot authenticate 802.1X clients without associating a RADIUS server to the WLAN.
5
Enable WLAN status and apply changes
Activates the WLAN on member Access Points for client probing and association.
By default, new WLANs are disabled; enabling status must occur after all dependencies (interface, security, AAA) are configured.

Anahtar Kavram

WLC GUI WLAN Configuration Sequence
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