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Tüm alıştırma soruları

1987 soru

Tüm türler1,987Çoktan seçmeli1,020Çoklu seçim452Sayısal18Eşleştirme229Sıralama203Boşluk doldurma22Kısa cevap43
Soru 1121Soru →

A network engineer is configuring interface GigabitEthernet1/0/12 on a Cisco Catalyst switch to connect an end-user workstation. The interface must be explicitly configured as a static, non-trunking Layer 2 port placed into VLAN 75. Which two Cisco IOS CLI commands must be executed within interface configuration mode to achieve this setup? (Select two.)

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Cevap: switchport mode access; switchport access vlan 75

Cevap

The correct commands to execute in interface configuration mode are 'switchport mode access' and 'switchport access vlan 75'.
Configuring a switch interface for an end-user host requires two distinct steps under interface configuration mode: explicitly declaring the Layer 2 operational mode as access ('switchport mode access') and specifying the target VLAN assignment for untagged frames ('switchport access vlan 75').

Adım Adım Çözüm

1
Set the administrative interface mode
Interface is explicitly designated as a Layer 2 access port
Executing 'switchport mode access' under interface configuration mode turns off dynamic trunking negotiations and forces the port into operational access mode.
2
Assign the interface to the target VLAN
Interface forwards untagged traffic into VLAN 75
Executing 'switchport access vlan 75' maps untagged frame ingress and egress on this interface directly to VLAN 75.

Anahtar Kavram

Static Access Port Configuration Syntax
Tahmini Süre:1m 30s
Soru 1122Soru →

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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Cevap

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 1123Soru →

A network engineer is designing a topology for a branch office with approximately 150 users across two floors. To minimize capital expenditure and management overhead while maintaining VLAN redundancy and routing capabilities between local subnets, the engineer selects a Cisco Collapsed Core topology instead of a traditional Cisco Three-Tier hierarchy. Which architectural modification defines this Collapsed Core implementation?

Cevabı ve açıklamayı göster

Cevap: The core layer and distribution layer functions are consolidated into a single pair of switches.

Cevap

The core layer and distribution layer functions are consolidated into a single pair of switches.
The defining characteristic of a Cisco Collapsed Core (two-tier) architecture is merging the core and distribution layers into a single pair of switches. This maintains key Layer 3 routing, policy enforcement, and redundancy functions while reducing overall equipment cost and administration complexity for small to medium enterprise sites.

Adım Adım Çözüm

1
Analyze the requirements of the branch office network design
The scenario requires connecting 150 users efficiently while reducing costs and complexity compared to a full three-tier campus design.
Smaller sites do not have sufficient scale or port-density demands to justify separate Core and Distribution switch pairs.
2
Compare traditional Three-Tier architecture against Collapsed Core (Two-Tier) architecture
A traditional Three-Tier topology consists of distinct Access, Distribution, and Core layers. A Collapsed Core merges the Core (high-speed transport) and Distribution (routing, ACLs, policy enforcement) responsibilities into one tier.
Consolidating these two layers into a single switch pair (collapsed core switches) provides Layer 3 boundaries and inter-VLAN routing while decreasing hardware footprint.

Anahtar Kavram

Cisco Collapsed Core Topology Architecture
Soru 1124Soru →

Host A with MAC address 0011.2233.4455 is connected to interface FastEthernet0/5 assigned to VLAN 20 on switch SW-Central. The MAC address table on SW-Central contains no existing entries for VLAN 20. When Host A transmits an ARP request frame to resolve its default gateway IP address, which operational sequence will SW-Central perform upon receiving the ingress frame?

Cevabı ve açıklamayı göster

Cevap: Learn source MAC 0011.2233.4455 on interface FastEthernet0/5 in VLAN 20, then flood the frame out all active interfaces assigned to VLAN 20 except FastEthernet0/5.

Cevap

The switch records MAC 0011.2233.4455 on interface FastEthernet0/5 in VLAN 20 and floods the frame out all active interfaces in VLAN 20 except FastEthernet0/5.
When a Layer 2 switch receives an Ethernet frame, it first updates its MAC address table by associating the source MAC address (0011.2233.4455) with the receiving port (FastEthernet0/5) and VLAN (VLAN 20). Next, because an ARP request uses the Ethernet broadcast destination address (FFFF.FFFF.FFFF), the switch floods the frame out every port in VLAN 20 except the ingress interface.

Adım Adım Çözüm

1
Examine the source MAC address of the incoming Ethernet frame.
The source MAC address 0011.2233.4455 is identified on port FastEthernet0/5.
Layer 2 switches perform dynamic MAC address learning by inspecting the source MAC field of all ingress frames.
2
Update the switch MAC address table for VLAN 20.
An entry mapping MAC 0011.2233.4455 to port FastEthernet0/5 in VLAN 20 is created.
MAC table entries are stored per-VLAN to maintain Layer 2 traffic isolation.
3
Examine the destination MAC address of the frame.
The destination MAC address is FFFF.FFFF.FFFF (Ethernet broadcast).
ARP requests use the broadcast destination MAC address so that all devices in the broadcast domain receive the query.
4
Forward the broadcast frame according to Layer 2 switching rules.
The frame is flooded to all active ports belonging to VLAN 20, excluding ingress port FastEthernet0/5.
Broadcast frames must reach all hosts in the same VLAN domain, but split-horizon logic prevents sending the frame back out its ingress port.

Anahtar Kavram

L2 Switch MAC Table Operation and Broadcast Flooding Rules
Tahmini Süre:1m 15s
Soru 1125Soru →

A network engineer is configuring network interfaces on a Cisco Wireless LAN Controller (WLC) to support enterprise wireless operations and administrative access. Which two statements accurately describe the operational roles and switch connectivity requirements of the WLC Management Interface compared to the Service Port? (Select TWO.)

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Cevap: The Management Interface terminates CAPWAP tunnels for lightweight AP communication and supports in-band administrative access via web GUI and SSH.; The Management Interface typically connects through a distribution port to an 802.1Q trunk port on the switch to transport tagged VLAN traffic.

Cevap

The WLC Management Interface terminates CAPWAP tunnels for lightweight AP communication while supporting in-band management, and it connects through a distribution port to an 802.1Q trunk port on the switch to transport tagged VLAN traffic.
The WLC Management Interface handles in-band management duties (GUI, SSH, SNMP) as well as CAPWAP control and data tunnel termination between APs and the controller. Because it resides on the WLC distribution port array, it connects to standard 802.1Q switch trunk ports configured with specific VLAN tags.

Adım Adım Çözüm

1
Identify the primary functions of the WLC Management Interface.
The Management Interface is an in-band logical interface used for administrative access (HTTP/HTTPS, SSH, SNMP) as well as establishing CAPWAP control and data tunnels with joined Access Points.
It acts as the default gateway address for controller communications across the enterprise network.
2
Analyze switchport connectivity for distribution system interfaces.
WLC distribution ports connect to switch ports configured as 802.1Q trunks so multiple logical interfaces (Management and Dynamic VLANs) can share physical links.
Trunking allows tagged frame transport across the underlying wired infrastructure.
3
Evaluate the Service Port constraints to eliminate incorrect options.
The Service Port is an out-of-band interface on an isolated physical port used for initial setup and recovery; it does not process CAPWAP traffic nor support 802.1Q VLAN trunking.
Distinguishing between in-band distribution interfaces and out-of-band physical interfaces ensures correct interface and trunking configurations.

Anahtar Kavram

WLC Management Interface vs. Service Port Operational Roles
Soru 1126Soru →

A network administrator configures an IEEE 802.1Q trunk link between two Cisco Catalyst switches. The trunk interface is configured to carry traffic for VLAN 10 (Data), VLAN 20 (configured as the native VLAN), and VLAN 30 (Voice). Which two statements accurately describe how traffic is processed over this trunk connection?

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Cevabı ve açıklamayı göster

Cevap: Frames belonging to VLAN 10 and VLAN 30 have a 4-byte 802.1Q header inserted into the Ethernet frame prior to transmission across the trunk.; Frames belonging to VLAN 20 are transmitted untagged across the trunk link under default 802.1Q operational behavior.

Cevap

The two correct statements are that frames belonging to VLAN 10 and VLAN 30 have a 4-byte 802.1Q header inserted into the Ethernet frame, and frames belonging to VLAN 20 are transmitted untagged across the trunk link under default 802.1Q operational behavior.
IEEE 802.1Q trunking inserts a 4-byte header into frames belonging to tagged VLANs (such as VLAN 10 and VLAN 30) so recipient switches can identify their origin. Additionally, under standard 802.1Q operation, traffic belonging to the configured native VLAN (VLAN 20) is transmitted across the trunk link without a tag.

Adım Adım Çözüm

1
Analyze standard IEEE 802.1Q encapsulation mechanics for tagged VLANs.
Frames belonging to non-native VLANs (VLAN 10 and VLAN 30) are tagged with a 4-byte 802.1Q header containing the Tag Protocol Identifier (TPID) and Tag Control Information (TCI).
802.1Q uses internal tagging to preserve VLAN identification across switch interconnects.
2
Evaluate the treatment of the designated native VLAN on an 802.1Q trunk link.
Frames associated with VLAN 20 (the native VLAN) are sent without an 802.1Q tag under default switch configurations.
IEEE 802.1Q natively supports untagged frames for backward compatibility with non-tagging legacy devices.
3
Evaluate ingress processing of untagged frames and native VLAN allowed list behavior.
Untagged ingress frames are mapped directly to the native VLAN rather than being dropped, and altering the native VLAN setting does not automatically prune VLAN 1.
Receptive untagged traffic maps directly to the port's native VLAN ID, while allowed VLAN lists require explicit configuration modifications.

Anahtar Kavram

802.1Q Trunking Frame Tagging and Native VLAN Operations
Soru 1127Soru →

A network engineer is deploying IPv6 across an enterprise branch using the assigned global unicast prefix 2001:db8:85a3::/482001:\text{db8}:85\text{a}3::/48. Interfaces are set to use SLAAC with EUI-64 interface identifier generation. Which two statements correctly describe the prefix subnetting and EUI-64 address generation for this implementation? (Select TWO.)

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Cevabı ve açıklamayı göster

Cevap: Subnetting the 2001:db8:85a3::/482001:\text{db8}:85\text{a}3::/48 prefix into standard /64/64 subnets yields 65,53665,536 (2162^{16}) unique subnets.; A host with MAC address 70:6D:15:AB:CD:EF70:6\text{D}:15:\text{AB}:\text{CD}:\text{EF} using EUI-64 auto-configuration generates the interface identifier 726D:15FF:FEAB:CDEF726\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}.

Cevap

Subnetting a /48/48 prefix into /64/64 subnets produces 65,53665,536 unique subnets, and converting the MAC address 70:6D:15:AB:CD:EF70:6\text{D}:15:\text{AB}:\text{CD}:\text{EF} via EUI-64 produces 726D:15FF:FEAB:CDEF726\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}.
Subnetting a /48/48 prefix to /64/64 provides 1616 subnet bits (64−48=1664 - 48 = 16), giving 216=65,5362^{16} = 65,536 subnets without subtracting any reserved subnets. Additionally, converting the MAC address 70:6D:15:AB:CD:EF70:6\text{D}:15:\text{AB}:\text{CD}:\text{EF} to EUI-64 splits the address into 706D:15706\text{D}:15 and AB:CD:EF\text{AB}:\text{CD}:\text{EF}, inserts FFFE\text{FFFE} to form 706D:15FF:FEAB:CDEF706\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}, and flips the 7th bit of 0x700\text{x}70 (0111 000020111\,0000_2) to 0x720\text{x}72 (0111 001020111\,0010_2), giving 726D:15FF:FEAB:CDEF726\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}.

Adım Adım Çözüm

1
Calculate the available subnet bits and total subnets from /48/48 to /64/64.
Subnet bits = 64−48=1664 - 48 = 16. Total subnets = 216=65,5362^{16} = 65,536.
IPv6 does not deduct subnets for network or broadcast designations.
2
Perform EUI-64 interface ID conversion on MAC address 70:6D:15:AB:CD:EF70:6\text{D}:15:\text{AB}:\text{CD}:\text{EF}.
Insert FFFE\text{FFFE} between 70:6D:1570:6\text{D}:15 and AB:CD:EF\text{AB}:\text{CD}:\text{EF} to get 706D:15FF:FEAB:CDEF706\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}. Flip the 7th bit of byte 11 (0x70=0111 00002→0111 00102=0x720\text{x}70 = 0111\,0000_2 \rightarrow 0111\,0010_2 = 0\text{x}72), yielding 726D:15FF:FEAB:CDEF726\text{D}:15\text{FF}:\text{FEAB}:\text{CDEF}.
EUI-64 standard requires inserting FFFE\text{FFFE} in the center of the MAC address and setting the U/L bit to 1 for globally unique scope.

Anahtar Kavram

IPv6 Subnetting & EUI-64 Address Generation
Soru 1128Soru →

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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Cevap

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 1129Soru →

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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Cevap

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 1130Soru →

An enterprise desktop administrator reports that newly provisioned Linux endpoints attached to switch port GigabitEthernet0/1 consistently fail to receive an IPv4 address via DHCP during system startup. However, if the DHCP client service is manually restarted 40 seconds after the operating system boots, an address is acquired successfully. The switch port is configured as a standard 802.1D access port. Which interface configuration command combination immediately resolves the boot-time DHCP timeout while ensuring the switch port is protected against unauthorized switches creating Layer 2 loops?

Cevabı ve açıklamayı göster

Cevap: Configure 'spanning-tree portfast' together with 'spanning-tree bpduguard enable' on GigabitEthernet0/1.

Cevap

The correct option specifies configuring 'spanning-tree portfast' along with 'spanning-tree bpduguard enable' directly on the edge access interface.
Enabling PortFast on access port GigabitEthernet0/1 causes the switch port to immediately transition from the Disabled/Blocking state directly into the Forwarding state when the physical link comes UP. This eliminates the 30-second 802.1D delay (15s Listening + 15s Learning), allowing the host's initial boot-time DHCP Discover request to pass through successfully. Furthermore, enabling BPDU Guard on the interface adds loop prevention: if a user plugs an unauthorized switch into GigabitEthernet0/1, the port receives BPDUs and is automatically placed into an err-disabled state.

Adım Adım Çözüm

1
Analyze the cause of the host DHCP timeout during bootup.
Standard 802.1D STP forces a newly connected link to pass through Listening (15 seconds) and Learning (15 seconds) states before reaching Forwarding (total 30 seconds delay). During this 30-second window, data frames including DHCP Discover messages are dropped.
Host operating systems typically issue DHCP requests immediately upon link UP and time out before STP transitions the port to Forwarding.
2
Determine the STP feature required to bypass listening and learning delays.
Cisco STP PortFast allows edge ports connected to single end-user devices to immediately enter the Forwarding state upon link UP.
PortFast bypasses the 30-second convergence delay, allowing instant frame transmission for DHCP initialization.
3
Identify the protection mechanism to prevent Layer 2 loops if a switch is plugged into a PortFast port.
STP BPDU Guard disables the PortFast-enabled port (placing it in err-disable state) upon receiving any BPDU frame.
Because PortFast ports transition directly to Forwarding without standard convergence analysis, receiving a BPDU indicates a potential switch or bridge attachment that could form a Layer 2 loop.

Anahtar Kavram

STP PortFast Immediate Forwarding and BPDU Guard Security Mechanics
Soru 1131Soru →

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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Cevap

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 1132Soru →

During a network link congestion event, a network administrator notices that file transfer sessions automatically reduce their sending rate to prevent buffer overflows, while a concurrent real-time voice stream continues transmitting at a constant rate despite dropping packets. Which transport layer characteristic accounts for this difference in behavior?

Cevabı ve açıklamayı göster

Cevap: TCP utilizes sliding window mechanisms and acknowledgement tracking for dynamic flow control, whereas UDP lacks native flow and congestion control mechanisms.

Cevap

TCP provides dynamic flow control and reliability through sliding windowing and acknowledgement tracking, whereas UDP is connectionless and lacks built-in flow or congestion control.
TCP is a stateful, connection-oriented protocol that features dynamic flow control mechanisms such as sliding windows and window size scaling. When network congestion occurs and packet loss is detected, TCP throttles its transmission window to adapt to path capacity. UDP is stateless and connectionless, possessing no mechanism for tracking delivered data or modifying sending rates in response to network congestion.

Adım Adım Çözüm

1
Analyze the observed protocol behaviors described in the scenario.
One application dynamically scales back its transmission rate upon encountering packet loss, whereas the other maintains a constant rate regardless of network drop rates.
This contrasts stateful, feedback-driven transport mechanisms with stateless, fire-and-forget transport mechanisms.
2
Compare TCP and UDP transport layer mechanics regarding flow and congestion control.
TCP uses sequence numbers, ACKs, and window size adjustments (sliding windowing) to regulate data delivery based on receiver capability and network path congestion. UDP has no windowing, acknowledgement system, or flow control capabilities.
Identifying protocol mechanisms confirms why TCP throttles during congestion while UDP continues sending uninterrupted.

Anahtar Kavram

TCP Connection-Oriented Flow Control vs UDP Connectionless Operation
Soru 1133Soru →

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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Cevap

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 1134Soru →

When creating a new Wireless LAN (WLAN) on a Cisco Wireless LAN Controller (WLC) using the web GUI, under which tab within the WLANs Edit menu is Pre-Shared Key (PSK) authentication configured for WPA2-Personal wireless clients?

Cevabı ve açıklamayı göster

Cevap: Security tab

Cevap

The Security tab is used to configure WPA2-Personal Pre-Shared Key (PSK) authentication on a Cisco Wireless LAN Controller GUI.
In the Cisco WLC web GUI, all Layer 2 and Layer 3 security protocols—including WPA2-Personal Pre-Shared Key (PSK) and WPA2-Enterprise (802.1X)—are configured under the Security tab of the WLANs > Edit page.

Adım Adım Çözüm

1
Navigate to the WLANs menu in the Cisco WLC GUI and select the target WLAN ID.
The WLANs > Edit page opens with several configuration tabs (General, Security, AAA Servers, QoS, Advanced).
Different WLAN parameters are segregated into functional tabs.
2
Select the Security tab and sub-tab Layer 2.
Layer 2 security mechanisms such as WPA+WPA2 are displayed.
Pre-Shared Key (PSK) is a Layer 2 security mechanism under the WPA/WPA2 policy.
3
Enable WPA2 Policy and set Auth Key Management to PSK, then enter the pre-shared key format and key value.
Client connectivity is configured to require the specified PSK for WPA2-Personal association.
This establishes client authentication criteria for the wireless network.

Anahtar Kavram

Cisco WLC GUI WLAN Security Configuration
Tahmini Süre:45s
Soru 1135Soru →

A network engineer is provisioning subnets from the enterprise address block 10.150.16.0/2010.150.16.0/20. The engineering requirement specifies creating a new subnet that supports a minimum of 115 usable host addresses while minimizing unused IP space. Previously, the block 10.150.16.0/2510.150.16.0/25 was allocated to VLAN 10, and 10.150.16.128/2610.150.16.128/26 was allocated to VLAN 20. Following sequential allocation and proper subnet boundary alignment rules, what is the broadcast address of the next valid subnet that fulfills the target host requirement?

Cevabı ve açıklamayı göster

Cevap: 10.150.17.12710.150.17.127

Cevap

The broadcast address of the next valid subnet meeting the host requirement is 10.150.17.12710.150.17.127.
To accommodate 115 hosts, a /25/25 subnet is required (27−2=1262^7 - 2 = 126 usable hosts). A /25/25 subnet has a block size of 128 and must start at either .0.0 or .128.128 in the fourth octet. Since 10.150.16.0/2510.150.16.0/25 occupies .0−.127.0 - .127 and 10.150.16.128/2610.150.16.128/26 occupies .128−.191.128 - .191, the .128.128 block in the 10.150.16.010.150.16.0 third octet is partially used and unavailable. Moving to the next binary-aligned /25/25 boundary yields 10.150.17.0/2510.150.17.0/25, which has a broadcast address of 10.150.17.12710.150.17.127.

Adım Adım Çözüm

1
Determine required prefix length for host sizing.
7 host bits needed (27−2=126≥1152^7 - 2 = 126 \ge 115), yielding a prefix of /25/25 (32−7=2532 - 7 = 25).
A /26/26 only yields 62 hosts (insufficient), while /25/25 provides 126 usable host addresses.
2
Identify boundary alignment rules for a /25/25 prefix.
Subnet block size is 128 (272^7). Valid /25/25 network boundaries in any octet must end on multiples of 128 (00 or 128128).
Subnet masks require binary boundaries; /25/25 subnets can only start at .0.0 or .128.128 in the fourth octet.
3
Evaluate existing allocations for address overlap.
10.150.16.0/2510.150.16.0/25 consumes 10.150.16.0−10.150.16.12710.150.16.0 - 10.150.16.127. 10.150.16.128/2610.150.16.128/26 consumes 10.150.16.128−10.150.16.19110.150.16.128 - 10.150.16.191.
The candidate block 10.150.16.128/2510.150.16.128/25 (10.150.16.128−10.150.16.25510.150.16.128 - 10.150.16.255) cannot be used because its first half is partially occupied by 10.150.16.128/2610.150.16.128/26.
4
Find the next available aligned /25/25 network address and calculate its broadcast address.
Next valid boundary is 10.150.17.0/2510.150.17.0/25. Network: 10.150.17.010.150.17.0, Broadcast: 10.150.17.12710.150.17.127.
Incrementing to the next /25/25 boundary gives 10.150.17.0/2510.150.17.0/25, whose broadcast address is 10.150.17.12710.150.17.127.

Anahtar Kavram

VLSM Subnet Sizing and Boundary Alignment
Tahmini Süre:2m 0s
Soru 1136Soru →

An administrator is configuring a trunk link between two Cisco Catalyst switches. Interface GigabitEthernet0/1 on Switch-1 is configured with `switchport mode dynamic auto` and `switchport trunk native vlan 50`. The connected interface GigabitEthernet0/1 on Switch-2 is configured with `switchport mode dynamic desirable` and `switchport trunk native vlan 10`. Which outcome will occur on this interswitch link?

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Cevap: The trunk link forms successfully, but CDP logs periodic native VLAN mismatch error messages, and untagged traffic on VLAN 50 from Switch-1 will leak into VLAN 10 on Switch-2.

Cevap

The interswitch link negotiates successfully into an 802.1Q trunk state because dynamic auto paired with dynamic desirable forms a trunk. However, because the native VLAN numbers do not match across switches, untagged traffic sent by Switch-1 on VLAN 50 will be treated as belonging to VLAN 10 by Switch-2, and CDP will log continuous native VLAN mismatch warnings.
When configuring DTP, pairing dynamic auto with dynamic desirable successfully forms an operational trunk. However, IEEE 802.1Q leaves native VLAN frames untagged. Switch-1 sends VLAN 50 traffic untagged, while Switch-2 interprets all incoming untagged traffic as belonging to its native VLAN (VLAN 10), leading to cross-VLAN traffic leakage and CDP logging native VLAN mismatch warnings.

Adım Adım Çözüm

1
Analyze DTP negotiation modes between Switch-1 and Switch-2.
Dynamic auto (passive waiting) combined with dynamic desirable (active requesting) results in an operational trunk link.
DTP modes determine whether the port becomes an access or trunk port regardless of VLAN tagging options.
2
Analyze IEEE 802.1Q native VLAN behavior across the link.
Untagged frames sent from VLAN 50 on Switch-1 cross the link without an 802.1Q header and are ingested into VLAN 10 by Switch-2.
802.1Q does not tag frames belonging to the configured native VLAN of the transmitting switch interface.
3
Evaluate CDP control plane protocol alerts.
CDP exchanges native VLAN information via TLVs and generates console log warnings while leaving the interface in the forwarding state.
CDP identifies configuration mismatches between neighbors but does not automatically err-disable the port.

Anahtar Kavram

802.1Q DTP Negotiation Mechanics and Native VLAN Mismatch Consequences
Tahmini Süre:1m 30s
Soru 1137Soru →

A network administrator is deploying switch configurations for end-user workstation ports in an enterprise network. Which two statements correctly describe the operational benefits and state transition changes when Cisco STP PortFast is enabled on an access interface?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The switch port bypasses the 802.1D Listening and Learning states, transitioning immediately from Blocking to Forwarding upon link bring-up.; Link state changes on the interface do not trigger Topology Change Notifications (TCNs) sent across the Spanning Tree domain.

Cevap

PortFast allows an access interface to bypass the Listening and Learning states to transition immediately to Forwarding, and it prevents interface status changes from generating Topology Change Notifications (TCNs) across the network.
PortFast provides two major operational benefits: it allows edge access ports to skip the 15-second Listening and 15-second Learning states to enter Forwarding instantly, and it prevents link up/down events on host ports from generating Topology Change Notifications (TCNs) that unnecessarily flush MAC tables network-wide.

Adım Adım Çözüm

1
Analyze the state transition behavior of PortFast.
Standard 802.1D STP takes 30 seconds (15s Listening + 15s Learning) before forwarding frames. PortFast bypasses these intermediary states to put the link into Forwarding immediately upon physical link detection.
End-user hosts need instantaneous network connectivity to complete initial protocol exchanges such as DHCP IP address assignment.
2
Analyze the impact of PortFast on STP topology change notifications (TCNs).
Normal STP topology changes trigger TCN BPDUs, instructing switches to reduce MAC table aging times. PortFast suppresses TCN generation for host connect/disconnect events.
Host link state toggles do not alter the physical path between switches, so flushing MAC address tables across the campus fabric is unnecessary.
3
Evaluate distractor statements regarding BPDU handling and trunk port usage.
PortFast alone does not filter BPDUs, nor is it safe for switch-to-switch interconnects.
Receiving a BPDU on a standard PortFast port causes it to lose PortFast status unless BPDU Guard is active, and enabling PortFast on trunks risks creating Layer 2 loops.

Anahtar Kavram

STP PortFast operational benefits and state transitions
Tahmini Süre:1m 15s
Soru 1138Soru →

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?

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

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 1139Soru →

A network administrator is setting up a Cisco Catalyst switch. Interface GigabitEthernet0/3 is connected to an end-user host that must belong to VLAN 45. VLAN 45 has not been previously created in the switch VLAN database. The administrator enters global configuration mode and executes the following commands:

Switch# configure terminal
Switch(config)# interface gigabitethernet0/3
Switch(config-if)# switchport access vlan 45

Which statement correctly describes the operational state of VLAN 45 and interface GigabitEthernet0/3 after these commands are executed?

Cevabı ve açıklamayı göster

Cevap: VLAN 45 is automatically created in the VLAN database, but the interface will still negotiate Dynamic Trunking Protocol (DTP) unless 'switchport mode access' is explicitly configured.

Cevap

VLAN 45 is automatically created in the VLAN database, but the interface will still negotiate Dynamic Trunking Protocol (DTP) unless 'switchport mode access' is explicitly configured.
When the 'switchport access vlan 45' command is entered for a VLAN that does not yet exist, Cisco IOS automatically creates VLAN 45 in the VLAN database (assigning a default name like VLAN0045). However, setting the access VLAN does not change the port's administrative trunking mode. On Cisco Catalyst switches with default DTP settings (dynamic auto or dynamic desirable), the interface will continue to attempt trunk negotiation unless 'switchport mode access' is explicitly configured to force static Layer 2 access mode.

Adım Adım Çözüm

1
Analyze the behavior of 'switchport access vlan <vlan-id>' when the target VLAN does not exist.
Cisco IOS automatically creates the non-existent VLAN in the VLAN database (e.g., % Access VLAN does not exist. Creating vlan 45).
IOS features automatic VLAN creation when assigning an access VLAN to an interface.
2
Evaluate the switchport mode state of the interface.
The command 'switchport access vlan 45' configures the access VLAN parameter, but does not explicitly change the interface mode to static access.
By default, Catalyst switch ports operate in dynamic mode (dynamic auto or dynamic desirable), meaning DTP frames are still sent/processed unless 'switchport mode access' is explicitly applied.
3
Determine the necessary complete configuration for a dedicated access port.
Both 'switchport mode access' (to statically force access mode and disable trunk negotiation) and 'switchport access vlan 45' are required.
Best practice requires explicit configuration of both switchport mode access and switchport access vlan.

Anahtar Kavram

Cisco IOS Automatic VLAN Creation and Access Port Command Requirements
Tahmini Süre:2m 0s
Soru 1140Soru →

In an enterprise network operating Rapid PVST+ for VLAN 2020, three Catalyst switches are interconnected as follows:

- Switch-A is configured with a base bridge priority of 40964096 and MAC address `0011.1111.1111`.
- Switch-B is configured with a base bridge priority of 2867228672 and MAC address `0022.2222.2222`.
- Switch-C is configured with a base bridge priority of 2867228672 and MAC address `0033.3333.3333`.

Switch-B and Switch-C both connect directly to Switch-A using single 1 Gbps1\text{ Gbps} trunk links on interface GigabitEthernet 0/1. In addition, Switch-B and Switch-C are connected directly to each other via two parallel 1 Gbps1\text{ Gbps} trunk links: Link 1 connects interface GigabitEthernet 0/2 on both switches, and Link 2 connects interface GigabitEthernet 0/3 on both switches. All switches maintain default port priorities of 128128.

Based on Rapid PVST+ operations for VLAN 2020, what are the port role and operational state of interface GigabitEthernet 0/3 on Switch-C?

Cevabı ve açıklamayı göster

Cevap: Alternate role and Discarding state

Cevap

Interface GigabitEthernet 0/3 on Switch-C operates in the Alternate role and Discarding state.
In Rapid PVST+, Switch-A is elected Root Bridge because it has the lowest Bridge ID (41164116). Switch-B and Switch-C both select GigabitEthernet 0/1 as their Root Port with a path cost of 44. On the parallel links between Switch-B and Switch-C, Switch-B wins the Designated Port election for both segments because its MAC address (`0022.2222.2222`) is lower than Switch-C's MAC address (`0033.3333.3333`), breaking the path cost tie. Because Switch-C receives BPDUs from a neighboring switch on GigabitEthernet 0/2 and 0/3, both interfaces serve as redundant paths to the root and are assigned the Alternate port role. Rapid PVST+ replaces the legacy 802.1D Blocking state with the Discarding state for non-forwarding ports.

Adım Adım Çözüm

1
Determine the Root Bridge for VLAN 20.
Switch-A Bridge Priority (4096+20=41164096 + 20 = 4116) is lower than Switch-B and Switch-C (28672+20=2869228672 + 20 = 28692). Switch-A is elected Root Bridge.
The bridge with the lowest Bridge ID (Priority + System ID Extension + MAC) becomes the Root Bridge.
2
Determine Root Ports on non-root switches.
Switch-B GigabitEthernet 0/1 (Cost 44) and Switch-C GigabitEthernet 0/1 (Cost 44) are elected Root Ports.
Direct 1 Gbps1\text{ Gbps} links to Switch-A provide the lowest cumulative Root Path Cost (44).
3
Evaluate Designated Port selection between Switch-B and Switch-C on parallel links (Gi0/2 and Gi0/3).
Switch-B advertises Root Path Cost 44, Switch-C advertises Root Path Cost 44. Ties are broken by Sender Bridge ID. Switch-B MAC (`0022.2222.2222`) < Switch-C MAC (`0033.3333.3333`). Switch-B wins Designated role on both Gi0/2 and Gi0/3.
On a segment between two switches with equal Root Path Cost, the switch with the lower Bridge ID becomes the Designated Switch.
4
Determine the port role and state for Switch-C's interfaces GigabitEthernet 0/2 and 0/3.
Both Gi0/2 and Gi0/3 on Switch-C receive superior BPDUs from Switch-B (a foreign switch). They are assigned the Alternate role and placed in the Discarding state.
In Rapid PVST+ (802.1w), ports receiving BPDUs from another switch that offer an alternate path to the root are Alternate ports and reside in the Discarding state.

Anahtar Kavram

Rapid PVST+ Port Roles (Root, Designated, Alternate, Backup) and 802.1w Operational States (Discarding, Learning, Forwarding)
Tahmini Süre:2m 0s
ÖncekiSayfa 57 / 100Sonraki
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