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1987 soru

Tüm türler1,987Çoktan seçmeli1,020Çoklu seçim452Sayısal18Eşleştirme229Sıralama203Boşluk doldurma22Kısa cevap43
Soru 81Soru →

A network administrator configures a single line standard IPv4 Access Control List (ACL) on a Cisco IOS router as follows:

`access-list 10 permit 192.168.1.50 0.0.0.0`

This ACL is applied inbound on interface GigabitEthernet0/0. What happens to incoming IP traffic with a source IPv4 address of 192.168.1.20 when it reaches interface GigabitEthernet0/0?

Cevabı ve açıklamayı göster

Cevap: The traffic is dropped because of the invisible implicit deny any clause at the end of the ACL.

Cevap

The traffic is dropped because of the implicit deny any clause at the end of the access control list.
In Cisco IOS, every Access Control List ends with an unwritten, invisible implicit deny clause (`deny ip any any` or `deny any`). Because the packet from source address 192.168.1.20 does not match the explicit permit rule for host 192.168.1.50, it falls through to the end of the list and is dropped.

Adım Adım Çözüm

1
Examine the configured access control list entries.
The ACL contains only one explicit permit line matching source host address 192.168.1.50.
Traffic from source IP 192.168.1.20 does not match this permit statement.
2
Evaluate default Cisco IOS ACL sequential processing behavior.
Every IPv4 ACL ends with an unwritten 'deny ip any any' (or 'deny any') statement.
Since the packet does not match any explicit permit line, it matches the implicit deny statement.
3
Determine the forwarding disposition of the packet.
The packet from source 192.168.1.20 is silently dropped by the router.
Implicit deny drops all traffic that is not explicitly permitted.

Anahtar Kavram

ACL Implicit Deny Clause
Soru 82Soru →

An enterprise network engineer is configuring a Cisco IOS router (R1) to forward DHCP requests from client hosts located on subnet 10.50.1.0/2410.50.1.0/24 to a centralized DHCP server with IPv4 address 172.16.10.25172.16.10.25. Client hosts connect directly to R1 via interface GigabitEthernet0/0/1 (10.50.1.1/2410.50.1.1/24), while interface GigabitEthernet0/0/0 (172.16.1.1/24172.16.1.1/24) routes traffic toward the DHCP server network. Which configuration command must be applied to ensure R1 properly relays client DHCP broadcast requests to the server?

Cevabı ve açıklamayı göster

Cevap: Apply the `ip helper-address 172.16.10.25` command under the incoming client gateway interface GigabitEthernet0/0/1 configuration mode.

Cevap

Apply the command `ip helper-address 172.16.10.25` on interface GigabitEthernet0/0/1.
To function as a DHCP relay agent, a Cisco router interface receiving client broadcast requests must be configured with `ip helper-address <server-ip>`. Applying this command to the client-facing gateway interface (GigabitEthernet0/0/1) enables the router to listen for UDP port 67 broadcast traffic, encapsulate it as unicast, insert its gateway IP address (`giaddr`), and send it directly to the designated DHCP server (172.16.10.25172.16.10.25).

Adım Adım Çözüm

1
Identify the ingress interface receiving client DHCP broadcasts
Interface GigabitEthernet0/0/1 receives the initial DHCPDISCOVER broadcast packets from client hosts on subnet 10.50.1.0/2410.50.1.0/24.
DHCP broadcast traffic (255.255.255.255255.255.255.255) is dropped by routers by default unless intercepted at the incoming gateway interface.
2
Determine the correct command syntax and placement for DHCP relay agent functionality
Executing `ip helper-address 172.16.10.25` within `config-if` mode on GigabitEthernet0/0/1 configures R1 to forward DHCP broadcasts as unicast packets to the target server IP address.
The router sets the `giaddr` (gateway IP address) field in the DHCP packet header to 10.50.1.110.50.1.1, allowing the remote server to select the correct IP pool.

Anahtar Kavram

DHCP Relay Agent Interface Placement and Operation
Tahmini Süre:1m 15s
Soru 83Soru →

An enterprise network topology consists of Access-Switch-1 linked via trunk interface GigabitEthernet1/0/24 to Distribution-Switch-1, where the network DHCP server resides. DHCP Snooping is enabled globally and on VLAN 20 across both switches. End hosts connected to access ports on Access-Switch-1 fail to acquire dynamic IPv4 addresses. System logs on Distribution-Switch-1 indicate that incoming DHCP Discover packets arriving on interface GigabitEthernet1/0/24 are being dropped upon arrival. Which configuration oversight is the root cause of these packet drops?

Cevabı ve açıklamayı göster

Cevap: Interface GigabitEthernet1/0/24 on Distribution-Switch-1 remains untrusted for DHCP Snooping, causing it to drop incoming DHCP client requests that contain Option 82 information inserted by Access-Switch-1.

Cevap

Interface GigabitEthernet1/0/24 on Distribution-Switch-1 remains untrusted for DHCP Snooping, causing it to drop incoming DHCP client requests that contain Option 82 information inserted by Access-Switch-1.
When DHCP Snooping is active, access switches append DHCP Option 82 (Relay Agent Information) to client requests. If an upstream switch receives a DHCP packet containing Option 82 on a port that is still in the default untrusted state, the switch drops the packet because untrusted ports are not allowed to receive DHCP packets with relay information when giaddr is 0.0.0.0. Designating the trunk interface as trusted using 'ip dhcp snooping trust' resolves the drops.

Adım Adım Çözüm

1
Analyze DHCP Snooping default behaviors on Cisco Catalyst access switches.
When DHCP Snooping is enabled globally, Cisco switches automatically insert DHCP Option 82 relay agent information into client DHCP requests originating on untrusted access ports before forwarding them upstream.
Option 82 adds circuit ID and remote ID details to assist DHCP servers with address allocation and policy enforcement.
2
Evaluate the receiving switch interface trust state.
By default, all switch ports (including 802.1Q trunks) are untrusted for DHCP Snooping until explicitly configured with the 'ip dhcp snooping trust' command.
Untrusted ports drop incoming DHCP packets containing non-zero Option 82 data when the gateway address (giaddr) is 0.0.0.0 to prevent DHCP spoofing.
3
Identify the corrective action required on the inter-switch trunk link.
Configuring 'ip dhcp snooping trust' on interface GigabitEthernet1/0/24 of Distribution-Switch-1 allows DHCP requests with Option 82 to pass through to the central DHCP server.
Trunk links pointing toward legitimate network infrastructure and DHCP servers must be designated as trusted interfaces.

Anahtar Kavram

DHCP Snooping Option 82 untrusted interface validation rules
Soru 84Soru →

Match each traditional network management practice on the left with its primary operational benefit provided by network automation on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Manual per-device CLI configuration
Periodic NMS SNMP polling
Ad-hoc manual changes per router

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Manual per-device CLI configuration matches with Rapid, consistent deployment using centralized templates; Periodic NMS SNMP polling matches with Near real-time data collection via model-driven push telemetry; Ad-hoc manual changes per router match with Reduction of human error and prevention of configuration drift.
Automation impacts network management by enabling centralized template-driven provisioning to replace CLI entries, utilizing push telemetry instead of polling, and establishing continuous compliance to eliminate configuration drift.

Adım Adım Çözüm

1
Identify the automated alternative to manual CLI provisioning.
Centralized controllers or scripts use templates to apply standardized configurations rapidly across many devices simultaneously.
Automation eliminates the need to connect to each network device individually via SSH or console.
2
Identify the automated advancement over legacy SNMP polling.
Streaming telemetry continuously pushes device performance data to monitoring systems.
Traditional SNMP pulls data periodically, whereas telemetry provides immediate visibility with lower CPU overhead.
3
Identify the operational benefit of eliminating ad-hoc per-device changes.
Standardized automated change execution prevents configuration drift and reduces human error.
Manual changes create inconsistent device states over time, which automation actively prevents.

Anahtar Kavram

Operational transformation from manual, per-device management to centralized, telemetry-driven automated network administration.
Soru 85Soru →

Match each component of the AAA security framework to its core administrative function.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Authentication
Authorization
Accounting

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Authentication maps to identity verification; Authorization maps to privilege and resource permission determination; Accounting maps to tracking, logging, and usage recording.
Authentication is responsible for verifying identity, Authorization restricts or allows actions based on permissions, and Accounting logs session and command activity for auditing purposes.

Adım Adım Çözüm

1
Identify the primary role of Authentication in the AAA framework.
Authentication answers 'Who are you?' by verifying credentials against a local database or remote AAA server.
Establishing identity is the essential first step before any network privileges can be evaluated.
2
Identify the primary role of Authorization in the AAA framework.
Authorization answers 'What are you allowed to do?' by specifying permissible CLI commands or VLAN assignments.
Access control policy enforcement requires explicit permission checks per user session.
3
Identify the primary role of Accounting in the AAA framework.
Accounting answers 'What did you do and for how long?' by capturing log entries and session statistics.
Auditing and compliance depend on maintaining accurate time-stamped logs of administrative actions.

Anahtar Kavram

Core Pillars of the AAA Security Framework (Authentication, Authorization, Accounting)
Soru 86Soru →

An application developer is configuring a telemetry collection service across a branch network. The service requires low transmission latency and minimal protocol processing overhead for periodic 50-byte metric updates. The developer selects User Datagram Protocol (UDP) instead of Transmission Control Protocol (TCP). Which characteristic of UDP directly accounts for its lower protocol overhead compared to TCP?

Cevabı ve açıklamayı göster

Cevap: UDP utilizes a fixed 8-byte header structure without connection establishment states or sequence tracking mechanisms.

Cevap

UDP utilizes a fixed 8-byte header structure without connection establishment states or sequence tracking mechanisms.
UDP reduces protocol overhead because its header is fixed at 8 bytes (containing only Source Port, Destination Port, Length, and Checksum) and it operates without connection setup (handshake), sequencing, or flow control state tracking.

Adım Adım Çözüm

1
Analyze transport protocol header overhead requirements.
TCP headers have a minimum size of 20 bytes, whereas UDP headers are fixed at 8 bytes.
Lower header overhead reduces bandwidth consumption for small payloads.
2
Evaluate transport protocol state tracking mechanisms.
TCP requires a 3-way handshake and tracks sequence/acknowledgment numbers, whereas UDP is connectionless and stateless.
Stateless transmission eliminates latency introduced by connection setup and flow control control loops.

Anahtar Kavram

Transport Layer Protocol Overhead and Header Comparison
Tahmini Süre:1m 30s
Soru 87Soru →

A network administrator needs to manually configure a static IEEE 802.1Q trunk on a Cisco Catalyst switch interface (GigabitEthernet0/1), set the native VLAN to VLAN 50, and disable Dynamic Trunking Protocol (DTP) frame transmission. What is the correct sequence of Cisco IOS configuration commands to accomplish this task?

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct sequence begins with entering interface configuration mode (`interface GigabitEthernet0/1`), explicitly setting the switchport mode to static trunk (`switchport mode trunk`), specifying the untagged native VLAN (`switchport trunk native vlan 50`), and finally disabling DTP frame negotiation (`switchport nonegotiate`).
To properly configure an 802.1Q trunk link with a custom native VLAN and suppressed DTP, an engineer must first enter interface configuration mode (`interface GigabitEthernet0/1`). Next, the port operational mode must be set to static trunking (`switchport mode trunk`). Once the port is in static trunk mode, the native VLAN can be configured (`switchport trunk native vlan 50`), followed by disabling DTP negotiations (`switchport nonegotiate`).

Adım Adım Çözüm

1
Enter interface configuration mode
Prompt changes to Switch(config-if)# for GigabitEthernet0/1
Cisco IOS requires navigating to the specific interface context before executing port configuration commands.
2
Set interface mode to trunk
Interface transitions to static trunk operational mode
Static trunking must be active before setting trunk-specific parameters or disabling dynamic DTP negotiation.
3
Specify custom native VLAN
VLAN 50 is assigned as the native VLAN for untagged ingress and egress frames
Overrides the default native VLAN 1 setting on the trunk link.
4
Disable DTP negotiation
Switch stops sending DTP negotiation frames out GigabitEthernet0/1
The switchport nonegotiate command is only valid on interfaces configured in static access or static trunk mode.

Anahtar Kavram

Static IEEE 802.1Q trunk configuration and DTP negotiation suppression on Cisco IOS switchports
Soru 88Soru →

Two Cisco Catalyst switches, SW1 and SW2, are connected via an IEEE 802.1Q trunk link. Interface GigabitEthernet0/1 on SW1 is configured with native VLAN 10, while interface GigabitEthernet0/1 on SW2 is configured with native VLAN 20. When a host in VLAN 10 connected to SW1 sends a broadcast frame across the trunk link, how does SW2 process this frame upon arrival?

Cevabı ve açıklamayı göster

Cevap: SW2 receives the untagged frame on its trunk interface and forwards it to all active ports assigned to VLAN 20, causing inter-VLAN traffic leakage.

Cevap

SW2 receives the untagged frame on its trunk interface and forwards it to all active ports assigned to VLAN 20, causing inter-VLAN traffic leakage.
Under IEEE 802.1Q trunking rules, frames belonging to the native VLAN are sent across the trunk link untagged. When SW1 sends a frame for VLAN 10, it strips any tag because VLAN 10 is its native VLAN. When SW2 receives this untagged frame on a trunk interface configured with native VLAN 20, SW2 associates all untagged incoming traffic with its local native VLAN (VLAN 20) and forwards it accordingly, resulting in inter-VLAN leakage between VLAN 10 and VLAN 20.

Adım Adım Çözüm

1
Analyze how 802.1Q handles native VLAN egress traffic on SW1
By default, IEEE 802.1Q trunk interfaces transmit frames belonging to the configured native VLAN without inserting a 4-byte 802.1Q tag header. Thus, SW1 transmits the VLAN 10 broadcast frame untagged.
802.1Q maintains backward compatibility with legacy non-trunking devices by omitting VLAN tags on the designated native VLAN.
2
Analyze how SW2 handles untagged ingress traffic on an 802.1Q trunk
When a switch receives an untagged frame on an 802.1Q trunk port, it automatically maps that frame to whichever VLAN is locally configured as the native VLAN on that specific interface. On SW2, the native VLAN is VLAN 20.
Switches rely entirely on local interface configuration to classify incoming untagged frames.
3
Determine the operational outcome of the mismatch
The broadcast frame sent by VLAN 10 on SW1 is flooded out ports in VLAN 20 on SW2, creating an unintended security vulnerability and cross-VLAN traffic leakage.
Mismatched native VLAN configurations merge separate broadcast domains at Layer 2.

Anahtar Kavram

802.1Q Native VLAN Tagging Mechanics and Mismatch Behavior
Tahmini Süre:1m 30s
Soru 89Soru →

A network administrator is connecting two Cisco Catalyst switches using an IEEE 802.3ad Link Aggregation Control Protocol (LACP) EtherChannel. SwitchA has its member interfaces configured with the command `channel-group 1 mode passive`. Which mode must be configured on SwitchB's corresponding member interfaces to successfully form the EtherChannel?

Cevabı ve açıklamayı göster

Cevap: active

Cevap

The mode 'active' must be configured on SwitchB.
The correct answer specifies 'active' mode. In LACP, 'active' mode actively sends LACP negotiation frames, whereas 'passive' mode only listens and responds. Because the remote switch is set to 'passive', the local switch must be set to 'active' to initiate communication and successfully build the bundle.

Adım Adım Çözüm

1
Identify the protocol associated with the configured mode.
The command 'mode passive' indicates the use of Link Aggregation Control Protocol (LACP), an open standard protocol.
EtherChannel negotiation protocols (LACP vs PAgP) cannot be mixed.
2
Analyze the operational state of LACP 'passive' mode on SwitchA.
SwitchA is in a passive state, meaning it will listen and respond to incoming LACP packets but will not initiate negotiation.
Two passive switches will wait indefinitely for the other to start negotiation, keeping the link down.
3
Determine the required mode for SwitchB.
SwitchB must be set to 'active' mode so that it actively transmits LACP packets to initiate channel creation.
An LACP EtherChannel requires at least one side to actively initiate negotiation (active-active or active-passive).

Anahtar Kavram

LACP Mode Compatibility
Soru 90Soru →

A network administrator is assigning an IPv4 address to an enterprise border router interface connected directly to an Internet Service Provider (ISP) WAN link. The interface must communicate on the public Internet without employing Network Address Translation (NAT). Which of the following IPv4 addresses is globally routable over the Internet according to RFC 1918 specifications?

Cevabı ve açıklamayı göster

Cevap: 172.32.50.1

Cevap

172.32.50.1 is a globally routable public address because it lies outside the RFC 1918 private address boundaries.
RFC 1918 defines three private IPv4 address ranges that are not routed on the public Internet: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The Class B range covers 172.16.0.0 through 172.31.255.255. The IP address 172.32.50.1 falls outside this range, making it a valid public IPv4 address suitable for Internet communication without NAT.

Adım Adım Çözüm

1
Recall the RFC 1918 private IPv4 address allocations.
Class A: 10.0.0.0/8 (10.0.0.0 to 10.255.255.255); Class B: 172.16.0.0/12 (172.16.0.0 to 172.31.255.255); Class C: 192.168.0.0/16 (192.168.0.0 to 192.168.255.255).
Identify which IP ranges are reserved for internal/private use and unroutable on the public Internet.
2
Evaluate each candidate IPv4 address against the RFC 1918 boundaries.
10.254.10.1 is in 10.0.0.0/8 (private). 192.168.250.1 is in 192.168.0.0/16 (private). 172.31.200.1 is in 172.16.0.0/12 (private). 172.32.50.1 is outside 172.16.0.0/12 (public).
The Class B private block ends at 172.31.255.255. Addresses starting at 172.32.0.0 are public IP addresses.
3
Select the address suitable for WAN interface routing without NAT.
172.32.50.1 is public and globally routable.
ISPs drop RFC 1918 private addresses at edge boundaries, so only public IP addresses can communicate over the global Internet without NAT.

Anahtar Kavram

RFC 1918 Private Address Ranges and Public Routability
Soru 91Soru →

A network administrator is installing an outdoor wireless point-to-point bridge between two campus buildings. The access point transmitter power is configured to 14 dBm14\text{ dBm}, the coaxial cable connecting the access point to the antenna introduces 3 dB3\text{ dB} of attenuation, and the directional antenna has a gain of 16 dBi16\text{ dBi}. What is the Effective Isotropic Radiated Power (EIRP) for this wireless installation?

Cevabı ve açıklamayı göster

Cevap: 27 dBm27\text{ dBm}

Cevap

The Effective Isotropic Radiated Power (EIRP) is 27 dBm27\text{ dBm}.
The correct calculation for Effective Isotropic Radiated Power (EIRP) accounts for the total power output from the transmitter, minus any insertion losses along the transmission cable, plus the passive power gain provided by the antenna. Computing 14 dBm−3 dB+16 dBi14\text{ dBm} - 3\text{ dB} + 16\text{ dBi} gives 27 dBm27\text{ dBm}.

Adım Adım Çözüm

1
Identify the given radio frequency values
Transmitter Power (PtxP_{\text{tx}}) = 14 dBm14\text{ dBm}, Cable Loss (LcableL_{\text{cable}}) = 3 dB3\text{ dB}, Antenna Gain (GantennaG_{\text{antenna}}) = 16 dBi16\text{ dBi}.
These parameters determine the total power radiated by the antenna in isotropic terms.
2
Apply the standard EIRP formula
EIRP=Ptx−Lcable+Gantenna\text{EIRP} = P_{\text{tx}} - L_{\text{cable}} + G_{\text{antenna}}
Cable attenuation reduces signal power before it reaches the antenna, while antenna gain focuses and boosts the radiated signal power.
3
Substitute the values into the formula and calculate
EIRP=14 dBm−3 dB+16 dBi=27 dBm\text{EIRP} = 14\text{ dBm} - 3\text{ dB} + 16\text{ dBi} = 27\text{ dBm}
Combining the transmitter output, cable attenuation, and passive antenna gain yields the total effective radiated power.

Anahtar Kavram

Effective Isotropic Radiated Power (EIRP) Calculation
Soru 92Soru →

A network technician is evaluating transport layer requirements for real-time application traffic. Which two features are characteristic of the User Datagram Protocol (UDP) rather than the Transmission Control Protocol (TCP)? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Low fixed header size of 8 bytes; Connectionless datagram delivery without handshake overhead

Cevap

The characteristics unique to UDP are its low fixed header size of 8 bytes and its connectionless datagram delivery without handshake overhead.
The correct features of UDP are its minimal 8-byte header length and connectionless nature, which avoids connection setup delays.

Adım Adım Çözüm

1
Identify transport layer protocol overhead differences
UDP relies on a simple 8-byte header (Source Port, Destination Port, Length, Checksum), whereas TCP requires a minimum 20-byte header.
Understanding header structure helps evaluate bandwidth and processing efficiency.
2
Evaluate connection state properties
UDP operates connectionlessly without requiring a initial three-way handshake.
Connectionless delivery minimizes latency for real-time applications.

Anahtar Kavram

UDP is a lightweight, connectionless transport layer protocol with minimal header overhead (8 bytes) and no built-in flow control or reliability mechanisms.
Soru 93Soru →

Host A sends an Ethernet frame addressed to Host B into port FastEthernet0/1 of a Layer 2 switch. The switch MAC address table already contains an entry for Host B on port FastEthernet0/2, but has no prior entry for Host A. What action does the switch take upon receiving this frame?

Cevabı ve açıklamayı göster

Cevap: Learns Host A's MAC address on port FastEthernet0/1 and forwards the frame directly out port FastEthernet0/2.

Cevap

The switch records Host A's MAC address on FastEthernet0/1 and forwards the frame exclusively out FastEthernet0/2.
When a switch receives a frame, it always inspects the source MAC address to update its MAC table (learning Host A on FastEthernet0/1). It then checks the destination MAC address; since Host B is already recorded on FastEthernet0/2, the switch forwards the frame exclusively out that destination port.

Adım Adım Çözüm

1
Examine the ingress frame's source MAC address
Host A's MAC address is learned and added to the MAC address table associated with port FastEthernet0/1.
Layer 2 switches dynamically populate their MAC address tables by inspecting incoming frame source MAC addresses and ingress port numbers.
2
Examine the ingress frame's destination MAC address
Host B's MAC address is found in the table associated with port FastEthernet0/2.
If the destination MAC address is already present in the MAC address table, the switch performs point-to-point known unicast forwarding.
3
Forward the frame
The frame is transmitted solely out port FastEthernet0/2.
Known unicast destination entries prevent unnecessary frame flooding across other switch ports.

Anahtar Kavram

Layer 2 MAC Address Table Learning and Forwarding Logic
Soru 94Soru →

A network engineer needs to build a functional Layer 3 LACP EtherChannel (Port-channel 10) between two Cisco Catalyst switches using interfaces GigabitEthernet1/0/1 and GigabitEthernet1/0/2. Place the required Cisco IOS CLI configuration steps in the correct order from start to finish.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct sequence for configuring a Layer 3 LACP EtherChannel is: first select the physical interface range (`interface range GigabitEthernet1/0/1 - 2`), disable Layer 2 switching on the physical ports (`no switchport`), create/assign the LACP active group (`channel-group 10 mode active`), enter the logical port-channel interface (`interface Port-channel 10`), and finally assign the IPv4 address (`ip address 192.168.10.1 255.255.255.252`).
To successfully configure a Layer 3 EtherChannel, physical member links must first be selected and converted into routed ports via the `no switchport` command. Next, the LACP dynamic protocol mode (`mode active`) is applied to bind the physical interfaces into channel-group 10. Finally, the network administrator enters the logical `interface Port-channel 10` configuration mode and assigns the IP address to the aggregate interface.

Adım Adım Çözüm

1
Select physical range
Enters range configuration mode `(config-if-range)` for member ports.
Allows simultaneous configuration of physical interfaces GigabitEthernet1/0/1 and GigabitEthernet1/0/2.
2
Execute `no switchport` on physical links
Member interfaces become routed ports.
Physical ports must be routed interfaces before being grouped into a Layer 3 EtherChannel.
3
Execute `channel-group 10 mode active`
Creates logical interface Port-channel 10 and binds member links using LACP.
The `active` keyword initiates LACP negotiation.
4
Enter `interface Port-channel 10`
Enters interface configuration mode `(config-if)` for the logical bundle.
Layer 3 parameters must be configured on the aggregate port-channel interface.
5
Assign IP address with `ip address 192.168.10.1 255.255.255.252`
Port-channel 10 is configured with a unicast IP address.
Completes Layer 3 routed EtherChannel setup.

Anahtar Kavram

Layer 3 EtherChannel Configuration Sequence
Soru 95Soru →

An administrator is configuring IPv6 addressing on a router interface and verifying reserved scope prefixes. Which two statements correctly describe IPv6 address representations and reserved prefix ranges? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The prefix fe80::/10 is reserved for IPv6 link-local addresses.; The IPv6 loopback address is represented as ::1/128.

Cevap

The prefix fe80::/10 is reserved for IPv6 link-local addresses, and the IPv6 loopback address is represented as ::1/128.
Link-local addresses strictly use the fe80::/10 prefix, and the loopback address for an IPv6 host interface is ::1/128.

Adım Adım Çözüm

1
Identify the reserved prefix ranges for link-local and unique local IPv6 address scopes.
The prefix fe80::/10 corresponds to link-local unicast addresses. The prefix fc00::/7 corresponds to Unique Local Addresses (ULA), not global unicast addresses (which use 2000::/3).
Understanding IPv6 scope prefixes is required to properly categorize address types.
2
Evaluate the rules of IPv6 address compression and special addresses.
The double colon (::) compression mechanism is allowed only once per address to maintain uncompressed length integrity. The IPv6 loopback address is designated as ::1/128.
RFC 4291 specifies rules for shortening IPv6 addresses and designates ::1/128 for node loopback testing.

Anahtar Kavram

IPv6 Address Scopes and Zero Compression Rules
Soru 96Soru →

A network administrator needs to aggregate physical interfaces GigabitEthernet0/1 and GigabitEthernet0/2 into a Layer 3 LACP EtherChannel (Port-channel 1) and assign an IP address of 10.1.1.1/30 to the logical interface. Place the configuration steps in the correct sequential order from first to last.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct configuration order is: 1) Select physical member ports (interface range GigabitEthernet0/1 - 2), 2) Disable Layer 2 switching (no switchport), 3) Associate ports with LACP channel-group (channel-group 1 mode active), 4) Enter logical port-channel mode (interface Port-channel 1), and 5) Assign the IP address (ip address 10.1.1.1 255.255.255.252).
To successfully configure a Layer 3 EtherChannel using LACP, physical member interfaces must first be selected (`interface range`), converted to routed ports (`no switchport`), and joined to an active LACP channel group (`channel-group 1 mode active`). Afterwards, the logical interface context must be accessed (`interface Port-channel 1`) to assign the designated IP address (`ip address 10.1.1.1 255.255.255.252`).

Adım Adım Çözüm

1
Select target physical interfaces
System enters interface range configuration mode prompt switch(config-if-range)#
Configuration commands must target both physical member interfaces simultaneously.
2
Execute 'no switchport' on physical member interfaces
Physical ports are converted from Layer 2 switch ports to Layer 3 routed ports
Layer 3 EtherChannels require member interfaces to operate in routed mode.
3
Execute 'channel-group 1 mode active'
Physical interfaces are added to EtherChannel group 1 using LACP active negotiation, creating Port-channel 1
The 'active' keyword enables dynamic IEEE 802.3ad LACP protocol negotiation.
4
Execute 'interface Port-channel 1'
System enters interface configuration mode for the logical port-channel switch(config-if)#
Layer 3 IP attributes must be applied directly to the logical bundled interface.
5
Execute 'ip address 10.1.1.1 255.255.255.252'
Logical interface Port-channel 1 receives the specified IP address and subnet mask
This enables routing over the aggregated logical EtherChannel link.

Anahtar Kavram

Layer 3 EtherChannel Configuration with LACP
Soru 97Soru →

Match each IPv6 address or prefix on the left with its corresponding functional characteristic or property on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

2001:db8:abc:1200::/562001:\text{db8}:\text{abc}:1200::/56
fd00:db8:abc:1200::/64fd00:\text{db8}:\text{abc}:1200::/64
fe80::200:5eff:fe00:5301
ff02::1:ff00:5301

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The correct pairings are: 2001:db8:abc:1200::/56 matches the global unicast prefix providing 256 subnets of /64 length; fd00:db8:abc:1200::/64 matches the unique local address prefix; fe80::200:5eff:fe00:5301 matches the link-local address created using EUI-64 from MAC 00:00:5e:00:53:01; and ff02::1:ff00:5301 matches the solicited-node multicast address.
Each IPv6 address and prefix matches its exact functional specification: 2001:db8:abc:1200::/56 yields 256 subnets of /64 size; fd00::/8 addresses are Unique Local Addresses; fe80::200:5eff:fe00:5301 correctly applies the 7th-bit flip and FFFE insertion to MAC 00:00:5e:00:53:01; and ff02::1:ff00:5301 uses the exact low 24 bits of the interface ID appended to the solicited-node multicast prefix.

Adım Adım Çözüm

1
Analyze the prefix length calculation for 2001:db8:abc:1200::/56
Difference between /64 and /56 is 8 bits (64−56=864 - 56 = 8). 28=2562^8 = 256 subnets.
Standard IPv6 subnets are designated at the /64 boundary.
2
Identify the IPv6 scope for fd00:db8:abc:1200::/64
Prefix starting with fd00::/8 is within fc00::/7.
fc00::/7 defines Unique Local Addresses (ULA), equivalent to IPv4 private addresses.
3
Perform Modified EUI-64 conversion on MAC 00:00:5e:00:53:01
First byte 0x00 binary (00000000) flipped 7th bit becomes 0x02 (00000010). Insert FFFE in center (0000:5E -> 0000:5EFF:FE00:5301). Prepend fe80:: prefix -> fe80::200:5eff:fe00:5301.
Modified EUI-64 flips the 7th bit (Universal/Local) and inserts FFFE between OUI and NIC specific bytes.
4
Derive the solicited-node multicast address for interface ID 0200:5eff:fe00:5301
Extract last 24 bits (00:5301) and append to prefix ff02::1:ff00:0/104 -> ff02::1:ff00:5301.
Solicited-node multicast addresses always start with ff02::1:ff00:0/104 and take the lowest 24 bits of the unicast address.

Anahtar Kavram

IPv6 Address Representation, Subnetting, Scopes, and EUI-64 / Solicited-Node Multicast Generation
Soru 98Soru →

A network administrator is setting up interswitch connectivity using standard IEEE 802.1Q trunking. Which action does IEEE 802.1Q take on Ethernet frames to identify VLAN membership as traffic traverses the trunk link?

Cevabı ve açıklamayı göster

Cevap: It inserts a 4-byte tag containing the VLAN ID directly into the Ethernet frame header between the Source MAC address and Type/Length fields.

Cevap

IEEE 802.1Q identifies VLAN membership by inserting a 4-byte header field into the Ethernet frame between the Source MAC address and the Length/Type fields.
IEEE 802.1Q performs internal frame tagging by inserting a 4-byte VLAN tag directly into the Ethernet header between the Source MAC address and the Length/Type fields. This tag includes the Tag Protocol Identifier (0x8100) and the 12-bit VLAN ID.

Adım Adım Çözüm

1
Identify the standard frame modification mechanism specified by IEEE 802.1Q for interswitch trunking.
IEEE 802.1Q inserts an in-line 4-byte VLAN tag into the existing Ethernet header.
In-line tagging allows switches on both ends of the trunk link to recognize which VLAN the frame belongs to without wrapping the entire frame in a separate encapsulation wrapper.
2
Analyze the position and structure of the 802.1Q tag.
The tag is placed between the Source MAC Address field and the Length/Type field.
This 4-byte tag includes the Tag Protocol Identifier (TPID 0x8100) and Tag Control Information (TCI), which holds the 12-bit VLAN Identifier (VID).

Anahtar Kavram

IEEE 802.1Q Frame Tagging Mechanics
Soru 99Soru →

A network administrator is replacing legacy Cisco access switches with multi-vendor infrastructure. On a Cisco Catalyst switch (SW-Access1), the administrator attempts to selectively enable Link Layer Discovery Protocol (LLDP) on interface GigabitEthernet1/0/5 to discover an adjacent non-Cisco VoIP gateway while disabling Cisco Discovery Protocol (CDP) on that specific link.

The administrator enters interface configuration mode and attempts the following command sequence:

SW-Access1(config)# interface gigabitethernet1/0/5
SW-Access1(config-if)# no cdp enable
SW-Access1(config-if)# lldp enable

The switch returns an error: `% Invalid input detected at '^' marker` pointing to the `enable` keyword.

Which combination of commands must the administrator issue to globally activate LLDP and correctly enable both transmission and reception of LLDP packets on interface GigabitEthernet1/0/5?

Cevabı ve açıklamayı göster

Cevap: Execute 'lldp run' in global configuration mode, and execute both 'lldp transmit' and 'lldp receive' in interface configuration mode.

Cevap

Execute 'lldp run' in global configuration mode, and execute both 'lldp transmit' and 'lldp receive' in interface configuration mode.
The correct answer specifies 'lldp run' in global configuration mode and both 'lldp transmit' and 'lldp receive' in interface configuration mode. In Cisco IOS, CDP and LLDP differ significantly in CLI command syntax and defaults. CDP is enabled globally by default and uses 'cdp enable' per interface. Conversely, LLDP is disabled globally by default (requiring 'lldp run') and controls interface communication via directional parameters ('lldp transmit' and 'lldp receive').

Adım Adım Çözüm

1
Identify the global configuration command required to enable LLDP across the Cisco Catalyst switch.
Unlike CDP which is enabled globally by default ('cdp run'), LLDP is disabled globally by default and must be enabled using the global configuration command 'lldp run'.
Global activation of the LLDP process is a prerequisite before interface-level behavior can be configured.
2
Analyze interface-level configuration syntax differences between CDP and LLDP in Cisco IOS.
CDP uses a simple binary interface toggle command ('cdp enable' / 'no cdp enable'). LLDP does not use the 'enable' keyword at the interface level; instead, it provides directional control using 'lldp transmit' and 'lldp receive'.
Attempting to enter 'lldp enable' on a Cisco IOS interface causes an invalid input error because 'enable' is not a valid sub-command under 'lldp'.
3
Synthesize the required global and interface commands to achieve the administrator's goal.
Issue 'lldp run' globally, and under interface GigabitEthernet1/0/5 issue 'no cdp enable', 'lldp transmit', and 'lldp receive'.
This setup disables CDP on the specific interface while enabling bidirectional LLDP communication with adjacent multi-vendor devices.

Anahtar Kavram

Cisco IOS CLI Syntax and Directional Operational Differences Between CDP and LLDP
Soru 100Soru →

An enterprise network engineer is analyzing DNS name resolution behavior across internal workstations and external edge firewalls. The infrastructure uses an internal Active Directory DNS server that forwards unknown domain requests to an external resolver. Which two statements correctly describe DNS transport protocol operation and name resolution roles in this environment?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Standard DNS queries and responses primarily utilize UDP port 53, but DNS transitions to TCP port 53 when a response payload exceeds 512 bytes (without EDNS0 extensions).; The internal Active Directory DNS server acts as a recursive resolver for enterprise client hosts while functioning as an authoritative server for the local internal domain namespace.

Cevap

The correct statements are that DNS queries primarily use UDP port 53 but switch to TCP port 53 when response payloads exceed 512 bytes without EDNS0, and that the internal Active Directory DNS server acts as a recursive resolver for internal clients while being authoritative for the local domain.
The correct options accurately identify that DNS relies primarily on UDP port 53 for standard client lookups, switching to TCP port 53 when responses exceed 512 bytes without EDNS0 extensions. Additionally, they correctly identify that an internal enterprise DNS server serves a dual role: authoritative for internal zone records and recursive resolver for endpoint clients requesting external or un-cached domain names.

Adım Adım Çözüm

1
Analyze transport layer protocol usage for DNS queries and responses.
DNS uses UDP port 53 for standard low-overhead queries and responses under 512 bytes. If a response sets the Truncation (TC) bit because it exceeds 512 bytes, the client re-issues the query using TCP port 53.
UDP avoids connection establishment latency for small lookup packets, but TCP provides reliable stream delivery for oversized payloads.
2
Evaluate the distinction between authoritative DNS servers and recursive resolvers.
An internal Active Directory DNS server holds authoritative records for internal resources (such as domain controllers and local hostnames) and resolves non-local queries on behalf of client hosts recursively or via forwarders.
Clients do not query root and TLD servers directly; they rely on their configured recursive resolver to navigate the DNS hierarchy or forward requests.
3
Evaluate incorrect protocol and role assumptions.
Zone transfers require TCP port 53 due to database size and reliability requirements. Clients do not default to TCP port 53 for normal queries, nor do authoritative-only servers perform recursion for external clients.
Distinguishing between control plane operations (zone transfers), data plane lookups (client queries), and server roles (authoritative vs. recursive) clarifies correct DNS architecture.

Anahtar Kavram

DNS Transport Protocols and Server Roles in Enterprise Networks
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