Tüm alıştırma soruları

1987 soru

Soru 1241Soru

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.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

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
Soru 1242Soru

A network administrator needs to assign an IPv4 address to the router interface serving a newly established remote VLAN. The subnet is carved from the 10.200.16.0/2010.200.16.0/20 parent address space and must support a maximum of 2828 end-user host devices using the most efficient subnet mask possible. The policy requires configuring the router interface with the last usable host IP address in the first available subnet block. Which IP address and subnet mask combination must be assigned to the router interface?

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Cevap: 10.200.16.30 255.255.255.224

Cevap

10.200.16.30 with subnet mask 255.255.255.224
To support 28 hosts, 5 host bits are required (252=302^5 - 2 = 30 usable addresses), yielding a /27 prefix (subnet mask 255.255.255.224). The first subnet derived from 10.200.16.0/20 is 10.200.16.0/27, which spans from 10.200.16.0 (network ID) to 10.200.16.31 (broadcast ID). The last usable host IP address in this range is 10.200.16.30.

Adım Adım Çözüm

1
Determine the required number of host bits (nn) for 2828 hosts.
Using the formula 2n2282^n - 2 \ge 28, n=5n = 5 host bits because 252=302^5 - 2 = 30 usable addresses (325=2732 - 5 = 27 prefix length or subnet mask 255.255.255.224255.255.255.224).
Selecting 4 host bits (/28) provides only 14 usable hosts, which falls short of the 28 required hosts.
2
Calculate the subnet boundaries for the first /27 subnet allocated from 10.200.16.0/2010.200.16.0/20.
Network Address: 10.200.16.0/2710.200.16.0/27; Broadcast Address: 10.200.16.3110.200.16.31.
A /27 subnet has a block size of 32 in the fourth octet (256224=32256 - 224 = 32).
3
Identify the usable host range and the last usable host IP address.
Usable host range: 10.200.16.110.200.16.1 to 10.200.16.3010.200.16.30. The last usable address is 10.200.16.3010.200.16.30.
The network ID (10.200.16.010.200.16.0) and broadcast ID (10.200.16.3110.200.16.31) cannot be assigned to network interfaces.

Anahtar Kavram

Subnet Host Calculation and Usable Address Boundaries
Soru 1243Soru

A network engineer is configuring static routes on a Cisco IOS router to establish reachability to remote networks. Which TWO commands represent syntactically valid IPv6 static route configurations?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: ipv6 route 2001:db8:acad:2::/64 gigabitethernet 0/0/0 fe80::1; ipv6 route 2001:db8:acad:3::/64 2001:db8:acad:1::2 130

Cevap

The syntactically valid IPv6 static route configurations are the fully specified route specifying both GigabitEthernet 0/0/0 and next-hop link-local address fe80::1, and the floating static route specifying the global unicast next-hop 2001:db8:acad:1::2 with an administrative distance of 130.
The command specifying both the exit interface GigabitEthernet 0/0/0 and the link-local next-hop address fe80::1 is valid because link-local addresses require an exit interface to define the link scope. The command specifying destination network 2001:db8:acad:3::/64 with global unicast next-hop 2001:db8:acad:1::2 and administrative distance 130 is also valid for configuring a floating static route.

Adım Adım Çözüm

1
Evaluate the link-local next-hop static route syntax requirements.
Link-local addresses (fe80::/10) require an exit interface to be specified because link-local addresses are only unique to a given link.
Cisco IOS cannot resolve an egress interface solely from a link-local next-hop address.
2
Evaluate global unicast static route syntax and administrative distance positioning.
Global unicast next-hop static routes can be configured with an optional administrative distance parameter at the end of the command.
Setting an administrative distance higher than dynamic routing protocols creates a backup or floating static route.

Anahtar Kavram

IPv6 Static Route Syntax Rules for Link-Local and Global Unicast Next Hops
Soru 1244Soru

A network workstation with MAC address 0010.7b33.44a1 is relocated from switch port GigabitEthernet0/1 to port GigabitEthernet0/2 on the same VLAN. Before the switch's MAC address table aging timer expires, the workstation sends an Ethernet frame out GigabitEthernet0/2 destined for a server with MAC address 0010.7b99.88c2. The server's MAC address is already dynamically mapped to port GigabitEthernet0/4 in the MAC address table. How does the switch process this incoming frame?

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Cevap: The switch updates the MAC address table entry for 0010.7b33.44a1 to point to GigabitEthernet0/2, then forwards the frame directly out GigabitEthernet0/4.

Cevap

The switch updates the MAC address table entry for the moving host to reflect the new ingress port (GigabitEthernet0/2) and forwards the frame directly out the destination port (GigabitEthernet0/4).
When a switch receives a frame, it reads the source MAC address to update its MAC address table. If the source MAC address is already listed but associated with a different interface, the switch instantly updates the entry to point to the new ingress interface (GigabitEthernet0/2). Next, the switch looks up the destination MAC address. Because the destination MAC address (0010.7b99.88c2) is already known and mapped to GigabitEthernet0/4, the switch performs known unicast forwarding directly to GigabitEthernet0/4.

Adım Adım Çözüm

1
Examine the source MAC address and ingress interface of the incoming frame.
Source MAC 0010.7b33.44a1 arrives on GigabitEthernet0/2.
Switches inspect the source MAC address of every ingress frame to build and maintain the MAC address table.
2
Update the MAC address table entry if the source MAC is missing or associated with a different port.
The existing entry for 0010.7b33.44a1 is updated from GigabitEthernet0/1 to GigabitEthernet0/2.
Dynamic MAC learning automatically updates port associations when a host moves to a new switch port within the same VLAN.
3
Lookup the destination MAC address in the MAC address table to determine forwarding behavior.
Destination MAC 0010.7b99.88c2 is found mapped to GigabitEthernet0/4.
Known unicast frames are forwarded exclusively out the specific port mapped in the MAC address table.

Anahtar Kavram

Layer 2 MAC Address Table Learning and Forwarding Operations
Tahmini Süre:1m 0s
Soru 1245Soru

An enterprise network deployment incorporates a Cisco Wireless LAN Controller (WLC) connected via four physical distribution system ports to a Cisco Catalyst switch stack. The network engineer enables Link Aggregation (LAG) globally on the controller and reboots the device. On the switch stack, the engineer attempts to establish the EtherChannel by configuring `channel-group 1 mode active` across ports GigabitEthernet 1/0/1 through 1/0/4. Following the WLC reboot, the controller loses all network management connectivity, and the switch logs indicate that the port-channel interface is down due to a negotiation failure. Which switch configuration modification will restore network connectivity while maintaining LAG operational on the controller?

Cevabı ve açıklamayı göster

Cevap: Change the channel group negotiation mode on all participating switch interfaces to mode on.

Cevap

Change the channel group negotiation mode on all participating switch interfaces to mode on.
When Link Aggregation (LAG) is enabled on a Cisco Wireless LAN Controller (running AireOS), the controller bundles all physical distribution system ports into a single operational interface. AireOS controllers do not support dynamic link negotiation protocols such as Link Aggregation Control Protocol (LACP) or Port Aggregation Protocol (PAgP). Therefore, the connected interfaces on the upstream Cisco Catalyst switch must be configured as a static EtherChannel using `channel-group <id> mode on`.

Adım Adım Çözüm

1
Analyze the WLC Link Aggregation (LAG) signaling requirements.
Cisco AireOS Wireless LAN Controllers require static EtherChannel bundling without dynamic LACP or PAgP negotiation frames.
The controller firmware bundles all physical distribution system ports into a single non-negotiated logical port.
2
Identify the cause of the port-channel down state on the switch.
The switch was configured with `channel-group 1 mode active`, expecting LACP LACPDU negotiation packets that the WLC never sends.
Because LACP negotiation times out without receiving LACPDUs from the WLC, the switch keeps the port-channel in a suspended/down state.
3
Determine the necessary configuration change on the switch stack.
Change the interface configuration to `channel-group 1 mode on` across all attached switch ports.
Mode `on` forces the switch ports into a static EtherChannel bundle without waiting for negotiation frames.

Anahtar Kavram

WLAN Controller Link Aggregation (LAG) Switch Configuration Requirements
Soru 1246Soru

A Cisco router currently learns the active route to destination network 2001:DB8:ACAD:20::/642001:\text{DB8}:\text{ACAD}:20::/64 via OSPFv3 with an administrative distance of 110. An engineer must configure a backup floating static IPv6 route to this remote network. The backup path uses the next-hop router's link-local IPv6 address FE80::2\text{FE80}::2 through the local interface GigabitEthernet0/0/1\text{GigabitEthernet0/0/1}. Which command correctly configures this floating static IPv6 route on the Cisco IOS router?

Cevabı ve açıklamayı göster

Cevap: ipv6 route 2001:db8:acad:20::/64 GigabitEthernet0/0/1 fe80::2 120

Cevap

The command 'ipv6 route 2001:db8:acad:20::/64 GigabitEthernet0/0/1 fe80::2 120' correctly configures the fully specified floating static IPv6 route.
The correct command fully specifies the exit interface alongside the link-local next-hop IPv6 address and sets an administrative distance of 120. In IPv6 static routing, specifying a link-local address as a next hop requires the local exit interface (GigabitEthernet0/0/1). Additionally, configuring an administrative distance greater than OSPFv3's default distance of 110 ensures the static route remains dormant in the routing table until the primary OSPFv3 route fails.

Adım Adım Çözüm

1
Identify the requirements for using a link-local IPv6 address as a static route next hop.
Because link-local addresses (FE80::/10) are ambiguous without a scope, Cisco IOS requires fully specified static routes that include both the local exit interface and the link-local next-hop address.
Without the local interface parameter, the router cannot determine which outgoing interface to send traffic to reach the link-local neighbor.
2
Determine the necessary Administrative Distance (AD) for a floating static route.
The AD must be strictly greater than the AD of the primary routing protocol (OSPFv3 default AD is 110). An AD value of 120 is higher than 110.
A floating static route remains inactive in the routing table until the primary route with a lower administrative distance fails.
3
Assemble the complete Cisco IOS IPv6 static route command syntax.
The correct command format is 'ipv6 route <destination-prefix/mask> <exit-interface> <next-hop-link-local-address> <administrative-distance>'.
This guarantees correct forwarding interface binding and proper floating route administrative distance operation.

Anahtar Kavram

IPv6 Fully Specified Floating Static Route Configuration
Soru 1247Soru

A network engineer is configuring network access for a newly installed Cisco Wireless LAN Controller (WLC) and Lightweight Access Points (APs). The WLC Management interface uses VLAN 10 to communicate with APs, while the Service Port is connected to a dedicated out-of-band management network. Which TWO statements accurately describe the operational requirements and characteristics of these management connections?

Geçerli olan tümünü seçin

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Cevap: The Service Port operates strictly out-of-band for administrative access and cannot terminate CAPWAP tunnels from APs.; The switch port connected to the WLC Management interface must allow VLAN 10 traffic to pass CAPWAP control and data packets.

Cevap

The Service Port provides out-of-band administrative management only and cannot terminate CAPWAP tunnels, while the switch port connected to the WLC Management interface must be configured to pass VLAN 10 traffic carrying CAPWAP control and data packets.
The correct options accurately identify the fundamental roles of Cisco WLC management access interfaces. The Service Port is dedicated to out-of-band administration and does not participate in CAPWAP data or control plane processing. The Management interface handles CAPWAP communication with APs, requiring the supporting switch interface to be configured with the appropriate VLAN access.

Adım Adım Çözüm

1
Analyze WLC Service Port functionality
Identify that the Service Port is isolated for out-of-band management and does not carry CAPWAP tunnel traffic from APs.
Out-of-band ports are non-routable in-band interfaces designed solely for administrative access to the WLC CLI/GUI.
2
Analyze WLC Management Interface requirements
Verify that the switchport trunking or VLAN settings must explicitly allow VLAN 10 so APs can establish CAPWAP tunnels to the WLC Management IP address.
The WLC Management interface handles in-band management and CAPWAP tunnel termination for Lightweight APs.
3
Evaluate distractor statements regarding STP PortFast and AP Local mode
Reject the statements advocating PortFast on trunk links and local switching by Local mode APs via the Service Port.
PortFast on standard trunks risks Layer 2 loops, and AP local switching requires FlexConnect mode, not default Local mode.

Anahtar Kavram

WLC Management Interface vs. Service Port Roles and Switch Interfacing
Soru 1248Soru

Match each network topology architecture on the left to its defining operational characteristic or primary design focus on the right. Which alignment correctly matches each architecture to its intended implementation traits?

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Spine-Leaf (Clos) Architecture
Three-Tier Campus Architecture
Collapsed Core Architecture
SOHO Network Topology

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Spine-Leaf Architecture aligns with delivering deterministic two-hop latency for east-west data center traffic; Three-Tier Campus Architecture aligns with segregating network roles into discrete Access, Distribution, and Core layers; Collapsed Core Architecture aligns with merging distribution routing and core switching into a single switch pair; and SOHO Network Topology aligns with integrating routing, switching, wireless, and firewall services into a single gateway appliance.
Each topology matches its core operational purpose: Spine-Leaf provides deterministic 2-hop latency for east-west data center traffic; Three-Tier segregates access, distribution, and core into separate layers for enterprise scaling; Collapsed Core merges distribution and core into a single switch pair for smaller campuses; and SOHO integrates all network services into one device.

Adım Adım Çözüm

1
Analyze the primary operational requirement of Spine-Leaf (Clos) topologies.
Identify that Spine-Leaf topologies use a two-tier full mesh between leaf and spine switches to optimize east-west traffic with predictable 2-hop latency and ECMP.
Spine-Leaf is designed specifically to overcome Spanning Tree bottlenecks in data centers.
2
Evaluate campus architecture options (3-Tier vs. Collapsed Core).
Map 3-Tier to distinct Access, Distribution, and Core layers, and Collapsed Core to designs where Distribution and Core functions share a single device pair.
Collapsed Core optimizes costs for medium sites, whereas 3-Tier scales up to multi-building enterprise environments.
3
Evaluate small office deployment characteristics.
Map SOHO topology to integrated single-appliance gateways combining WAN, LAN switch ports, wireless, and security services.
SOHO environments prioritize low footprint, simplicity, and integrated functions over hierarchical multi-switch scaling.

Anahtar Kavram

Enterprise Network Topology Architectures (3-Tier, Collapsed Core, Spine-Leaf, and SOHO)
Soru 1249Soru

A network administrator needs to configure a routed (Layer 3) EtherChannel bundle (Port-channel 10) on a Cisco switch using Link Aggregation Control Protocol (LACP) active mode across physical interfaces GigabitEthernet 0/1 and GigabitEthernet 0/2. What is the correct sequence of CLI steps to complete this configuration?

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct configuration order requires first selecting the physical member interfaces, disabling Layer 2 switching on them using 'no switchport', adding them to channel-group 10 with LACP active mode, navigating into interface Port-channel 10 mode, and finally ensuring Layer 3 operation with an IP address assigned to the logical interface.
To build a Layer 3 EtherChannel using LACP, an engineer must first select physical member ports, convert them into routed ports with 'no switchport', add them to the channel group using 'channel-group 10 mode active', navigate to the logical 'interface Port-channel 10', and assign the IP address to the logical port-channel interface.

Adım Adım Çözüm

1
Select physical member links
Enters interface range configuration mode for GigabitEthernet 0/1 and 0/2.
Changes must be applied to both physical candidate interfaces simultaneously.
2
Disable switchport mode on member links
Converts physical member interfaces from Layer 2 switchports to Layer 3 routed interfaces.
A Layer 3 EtherChannel requires member interfaces to be configured with 'no switchport' prior to bundle creation.
3
Bind member interfaces to LACP channel group
Configures LACP active mode and creates logical interface Port-channel 10.
The 'mode active' keyword enables LACP active negotiation.
4
Select logical Port-channel interface
Enters interface configuration mode for interface Port-channel 10.
Global network addressing must be applied to the bundle interface, not physical member links.
5
Configure IP address on logical interface
Disables switchport mode on the logical port-channel (if needed) and assigns the IPv4 address.
IP addresses in a Layer 3 EtherChannel reside on the logical Port-channel interface itself.

Anahtar Kavram

Layer 3 LACP EtherChannel CLI configuration order
Tahmini Süre:1m 30s
Soru 1250Soru

Refer to the following routing table snippet from a Cisco router:

text
Gateway of last resort is 10.0.0.1 to network 0.0.0.0

O 192.168.1.0/24 [110/20] via 10.1.1.1, GigabitEthernet0/0
D 192.168.1.128/26 [90/307200] via 10.2.2.2, GigabitEthernet0/1
S 192.168.1.136/29 [1/0] via 10.3.3.3, GigabitEthernet0/2
S* 0.0.0.0/0 [1/0] via 10.0.0.1, GigabitEthernet0/3

When the router receives an IP packet destined for 192.168.1.138192.168.1.138, which next-hop IP address and exit interface will the router select to forward the packet?

Cevabı ve açıklamayı göster

Cevap: 10.3.3.3 via GigabitEthernet0/2

Cevap

10.3.3.3 via GigabitEthernet0/2
When a router makes a forwarding decision, it evaluates all matching routes in its routing table and selects the one with the longest prefix mask length (most specific route). The destination IP address 192.168.1.138 is contained within 192.168.1.0/24, 192.168.1.128/26, 192.168.1.136/29, and 0.0.0.0/0. Among these matching entries, 192.168.1.136/29 has the longest subnet mask (/29). Therefore, the packet is forwarded to next-hop 10.3.3.3 out of GigabitEthernet0/2.

Adım Adım Çözüm

1
Evaluate all routes in the routing table against destination IP 192.168.1.138192.168.1.138.
Matching routes are 192.168.1.0/24192.168.1.0/24, 192.168.1.128/26192.168.1.128/26 (range 192.168.1.128192.168.1.191192.168.1.128 - 192.168.1.191), 192.168.1.136/29192.168.1.136/29 (range 192.168.1.136192.168.1.143192.168.1.136 - 192.168.1.143), and 0.0.0.0/00.0.0.0/0.
The destination address must fall within the subnet range of a candidate route.
2
Apply the Longest Prefix Match (LPM) rule to select the best matching route.
The route 192.168.1.136/29192.168.1.136/29 has a mask length of /29/29, which is longer (more specific) than /26/26, /24/24, and /0/0.
Routers always prioritize the route with the longest matching subnet mask length regardless of Administrative Distance or metric.
3
Identify the next-hop IP and exit interface associated with the chosen LPM route.
The route 192.168.1.136/29192.168.1.136/29 specifies next-hop 10.3.3.310.3.3.3 via interface `GigabitEthernet0/2`.
The forwarding engine uses the egress parameters defined by the winning route entry.

Anahtar Kavram

Longest Prefix Match Rule in Router Forwarding Decisions
Tahmini Süre:1m 0s
Soru 1251Soru

A network engineer is configuring a dedicated voice wireless network for wireless IP phones using the Cisco Wireless LAN Controller (WLC) web GUI. To ensure optimal performance and security, the engineer must set the Quality of Service (QoS) profile to Platinum (Voice) and restrict direct traffic between wireless clients on the same WLAN by enabling Peer-to-Peer Blocking. Which combination of GUI tabs under WLANs > Edit must the engineer access to configure these two settings?

Cevabı ve açıklamayı göster

Cevap: Configure the QoS profile under the QoS tab, and configure Peer-to-Peer Blocking under the Advanced tab.

Cevap

Configure the QoS profile under the QoS tab, and configure Peer-to-Peer Blocking under the Advanced tab.
In the Cisco AireOS WLC web interface, editing a WLAN presents several dedicated tabs: General, Security, QoS, Policy-Mapping, AAA Servers, DNS, Device Analytics, IPv6, Advanced, and FlexConnect. The QoS tab specifies the Quality of Service profile (Platinum, Gold, Silver, Bronze) applied to client traffic. The Advanced tab controls operational client behavior and features, including Peer-to-Peer Blocking (Disabled, Drop, or Upstream-Forward), AAA Override, Mandatory DHCP, and Client Exclusion.

Adım Adım Çözüm

1
Identify the WLC GUI navigation path for Quality of Service (QoS) profile settings.
In the Cisco WLC web GUI, navigate to WLANs > WLANs > Edit '[WLAN Name]' and select the QoS tab to choose the Quality of Service profile (Platinum/Voice).
QoS profiles determine packet marking and prioritization policies for wireless traffic and are located on the dedicated QoS tab.
2
Identify the WLC GUI navigation path for Peer-to-Peer (P2P) Blocking configuration.
Under WLANs > WLANs > Edit '[WLAN Name]', select the Advanced tab and locate the Peer-to-Peer Blocking Action drop-down menu.
Peer-to-Peer Blocking prevents client-to-client communication within the same WLAN and is categorized under operational WLAN behavior on the Advanced tab.

Anahtar Kavram

Cisco WLC GUI WLAN Configuration Tabs and Parameter Mapping
Soru 1252Soru

An administrator examines the following output from a Cisco router's IPv4 routing table:

text
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 6 subnets, 3 masks
O 10.20.30.0/24 [110/20] via 192.168.12.2, 00:15:32, GigabitEthernet0/0
D 10.20.30.32/28 [90/307200] via 192.168.23.2, 01:42:10, GigabitEthernet0/1
S 10.20.30.40/29 [1/0] via 192.168.34.2
O IA 10.20.30.44/30 [110/50] via 192.168.45.2, 00:08:19, GigabitEthernet0/2

Which two statements accurately interpret the components and forwarding behavior of this routing table? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Packets destined for host 10.20.30.45 will be egressed via interface GigabitEthernet0/2 because 10.20.30.44/30 provides the longest matching prefix for that destination address.; The bracketed notation [90/307200] in the 10.20.30.32/28 route entry specifies an Administrative Distance of 90 and an EIGRP composite metric of 307200.

Cevap

The correct statements are that packets for destination 10.20.30.45 will exit via GigabitEthernet0/2 due to longest prefix match (/30), and that [90/307200] defines an Administrative Distance of 90 and metric of 307200.
The router uses the Longest Prefix Match rule during packet lookup. Since destination 10.20.30.45 falls into 10.20.30.44/30 (range 10.20.30.44 to 10.20.30.47), the /30 prefix length is the longest and takes precedence over /29, /28, and /24. Additionally, routing table bracket notation [X/Y] represents [Administrative Distance / Metric], correctly mapping [90/307200] to AD 90 and EIGRP metric 307200.

Adım Adım Çözüm

1
Evaluate subnet range matching for target IP address 10.20.30.45 across all routing table entries.
The target address 10.20.30.45 matches 10.20.30.0/24, 10.20.30.32/28 (32-47), 10.20.30.40/29 (40-47), and 10.20.30.44/30 (44-47).
Before making forwarding decisions, the router determines which routing table prefixes encompass the destination address.
2
Apply the Longest Prefix Match (LPM) rule to select the forwarding route.
Prefix length /30 is more specific than /29, /28, and /24. The route 10.20.30.44/30 is selected.
Routers always prioritize the longest (most specific) network mask when choosing between matching routing entries, regardless of Administrative Distance.
3
Interpret routing table component metrics in the brackets [X/Y].
[90/307200] corresponds to AD=90 (Internal EIGRP) and Metric=307200.
The first number inside the brackets is Administrative Distance (trustworthiness), and the second number is the path metric.

Anahtar Kavram

Routing Table Components and Longest Prefix Match Forwarding Logic
Soru 1253Soru

A network engineer is configuring Layer 2 neighbor discovery on a Cisco Catalyst switch connected to both Cisco switches and third-party network endpoints. Which two statements correctly describe the operational characteristics and default behaviors of Cisco Discovery Protocol (CDP) and Link Layer Discovery Protocol (LLDP)? (Choose two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: CDP is a Cisco proprietary protocol enabled by default with a 60-second update timer, whereas LLDP is an IEEE 802.1AB standard that uses a 30-second update timer by default.; Both CDP and LLDP use Type-Length-Value (TLV) structures within Layer 2 frames to convey neighbor information such as device capabilities, port identifiers, and management addresses.

Cevap

CDP is a Cisco proprietary protocol enabled by default with a 60-second update timer, whereas LLDP is an IEEE 802.1AB standard that uses a 30-second update timer by default; both CDP and LLDP use Type-Length-Value (TLV) structures within Layer 2 frames to convey neighbor information.
CDP is a Cisco proprietary protocol operating with a 60-second update timer and 180-second holdtime, whereas LLDP is an open standard defined by IEEE 802.1AB that operates with a 30-second update timer and 120-second holdtime. Both protocols organize neighbor information using Type-Length-Value (TLV) structures within Layer 2 frames.

Adım Adım Çözüm

1
Identify default protocol parameters and standards for CDP and LLDP.
CDP is Cisco proprietary (default 60-second update, 180-second holdtime), while LLDP is defined by IEEE 802.1AB (default 30-second update, 120-second holdtime).
Distinguishing between proprietary and open standards along with their default timer values is essential for multi-vendor network administration.
2
Analyze frame structure and data encoding methods.
Both protocols encapsulate neighbor metadata into modular Type-Length-Value (TLV) elements transmitted inside Data Link layer frames.
TLVs allow flexible exchange of system attributes, management IP addresses, and port descriptions across Layer 2 neighbors.
3
Evaluate protocol reaction to native VLAN configuration errors.
Layer 2 discovery protocols report mismatches using log messages but do not alter port forwarding states or block traffic.
Traffic suppression due to misconfiguration is handled by Spanning Tree Protocol (STP) mechanisms, not CDP or LLDP.

Anahtar Kavram

Layer 2 Discovery Protocols (CDP and LLDP) standards, default timers, and TLV structure
Soru 1254Soru

A network administrator is configuring IPv6 static routing on router R1 to reach network 2001:db8:89ab:10::/642001:\text{db8}:89\text{ab}:10::/64. The directly connected neighbor router interface is configured with global unicast address 2001:db8:1234:1::22001:\text{db8}:1234:1::2 and link-local address fe80::2\text{fe80}::2. Router R1 uses local interface GigabitEthernet0/1 to reach this neighbor. Which TWO Cisco IOS commands represent valid IPv6 static route configurations on R1?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: ipv6 route 2001:db8:89ab:10::/64 GigabitEthernet0/1 fe80::2; ipv6 route 2001:db8:89ab:10::/64 2001:db8:1234:1::2

Cevap

The two valid Cisco IOS static route commands are 'ipv6 route 2001:db8:89ab:10::/64 GigabitEthernet0/1 fe80::2' and 'ipv6 route 2001:db8:89ab:10::/64 2001:db8:1234:1::2'.
In Cisco IOS, IPv6 static routes configured with a link-local address as the next hop MUST include the local egress interface (fully specified route). Alternatively, a global unicast next-hop address can be configured directly without an egress interface specified.

Adım Adım Çözüm

1
Identify valid next-hop options for Cisco IOS IPv6 static routes
IPv6 static routes can use a global unicast next-hop address alone, an outbound local interface with a global unicast address, or a fully specified combination of local exit interface and link-local next-hop address.
Link-local addresses have link-local scope and exist on multiple interfaces simultaneously, making the exit interface strictly mandatory when using link-local next hops.
2
Evaluate the option using local exit interface and link-local address
The command specifying GigabitEthernet0/1 alongside link-local address fe80::2 is valid.
It fulfills the mandatory requirement of declaring the local egress interface when referencing link-local IPv6 addresses.
3
Evaluate the option using global unicast next-hop address
The command specifying next-hop global unicast address 2001:db8:1234:1::2 is valid.
Global unicast addresses are globally unique and routable without explicit interface identification.

Anahtar Kavram

IPv6 Static Route Next-Hop Requirements
Soru 1255Soru

A network engineer needs to manually configure a backup route on Router R1 toward the remote prefix 2001:db8:cafe:40::/642001:\text{db8}:\text{cafe}:40::/64. The primary route to this subnet is learned via OSPFv3 with an administrative distance of 110. The engineer must use the neighboring router's link-local address fe80::250:56ff:fe9a:12ab\text{fe80}::250:56ff:\text{fe9a}:12ab reachable through interface GigabitEthernet0/0/1. What complete Cisco IOS global configuration command must be entered to establish this route as a floating static route with an administrative distance of 130?

Aşağıdaki boşlukları doldurun

R1(config)#
Cevabı ve açıklamayı göster

Cevap

The complete command required is 'ipv6 route 2001:db8:cafe:40::/64 GigabitEthernet0/0/1 fe80::250:56ff:fe9a:12ab 130'.
To route IPv6 traffic using a link-local address (FE80::/10) as the next hop, Cisco IOS requires a fully specified static route syntax that defines the local exit interface followed by the link-local address. Without specifying the exit interface, the router cannot determine which local physical or logical link reaches that link-local address. Additionally, appending the administrative distance value 130 ensures the static route remains inactive in the routing table until the primary OSPFv3 route (AD 110) fails.

Adım Adım Çözüm

1
Identify the base global configuration command for IPv6 static routing.
The command structure starts with 'ipv6 route'.
Cisco IOS requires 'ipv6 route' in global configuration mode to declare static routes for IPv6.
2
Append the destination IPv6 prefix and prefix-length.
Add '2001:db8:cafe:40::/64' after the command keyword.
Static routing requires specifying the exact destination prefix using CIDR slash notation.
3
Identify the mandatory parameters when utilizing a link-local address as the next hop.
Specify the local exit interface 'GigabitEthernet0/0/1' immediately followed by the link-local address 'fe80::250:56ff:fe9a:12ab'.
Because link-local addresses (FE80::/10) are only unique on a per-link basis, Cisco IOS requires a fully specified static route containing both the outbound interface and the next-hop link-local IP.
4
Set the administrative distance for floating route behavior.
Append '130' at the end of the command.
A primary OSPFv3 route has an administrative distance of 110. To function as a backup floating static route, the static route's administrative distance must be higher than 110.

Anahtar Kavram

Fully Specified IPv6 Floating Static Route Configuration
Soru 1256Soru

Refer to the following partial IPv4 routing table output from a Cisco router:

text
Gateway of last resort is 10.0.0.1 to network 0.0.0.0

S* 0.0.0.0/0 [1/0] via 10.0.0.1
O 172.31.0.0/16 [110/20] via 10.1.1.1, GigabitEthernet0/0
D 172.31.50.0/24 [90/307200] via 10.2.2.2, GigabitEthernet0/1
S 172.31.50.96/28 [1/0] via 10.3.3.3, GigabitEthernet0/2

When the router receives an IP packet destined for 172.31.50.100172.31.50.100, which TWO statements correctly describe how the router makes its forwarding decision?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The router selects the route 172.31.50.96/28 because it has the longest matching prefix length (/28) for destination 172.31.50.100.; The packet is forwarded out interface GigabitEthernet0/2 toward next-hop IP address 10.3.3.3.

Cevap

The router forwards the packet out interface GigabitEthernet0/2 toward next-hop 10.3.3.3 after selecting 172.31.50.96/28 as the longest prefix match.
When an IPv4 packet arrives, a router evaluates all matching routes in its routing table and selects the entry with the longest prefix length (most specific subnet mask). Here, destination 172.31.50.100 matches 0.0.0.0/0 (/0), 172.31.0.0/16 (/16), 172.31.50.0/24 (/24), and 172.31.50.96/28 (/28). The /28 route is the longest match. Therefore, the router forwards the packet out interface GigabitEthernet0/2 to next-hop 10.3.3.3.

Adım Adım Çözüm

1
Evaluate all routing table entries that match the destination IP address 172.31.50.100.
The destination matches four entries: 0.0.0.0/0, 172.31.0.0/16, 172.31.50.0/24, and 172.31.50.96/28.
All four network routes encompass the destination IP address 172.31.50.100.
2
Apply the Longest Prefix Match (LPM) rule to select the best route.
172.31.50.96/28 is chosen because /28 is the longest prefix mask (most specific match).
A router always prefers the route with the highest number of matching network bits before considering Administrative Distance or Metric.
3
Identify the next-hop IP and egress interface configured for the winning route.
The entry 172.31.50.96/28 specifies next-hop 10.3.3.3 and egress interface GigabitEthernet0/2.
The router uses the exact forwarding attributes bound to the selected longest matching route entry.

Anahtar Kavram

Router Forwarding Decision Logic (Longest Prefix Match)
Soru 1257Soru

A network administrator is assigned the IPv4 address block 10.50.0.0/2210.50.0.0/22 to provision subnets for an enterprise IP telephony deployment. Each subnet requires support for at least 5050 usable host IP addresses. If the administrator subnets the entire 10.50.0.0/2210.50.0.0/22 block using a uniform prefix length that meets this host requirement with minimal wasted host space, how many total subnets can be created?

Cevabı ve açıklamayı göster

Cevap: 16

Cevap

16 subnets can be created from the block.
To support at least 50 usable host IP addresses per subnet, 6 host bits are needed (262=622^6 - 2 = 62 usable IPs), which corresponds to a /26 prefix length (326=2632 - 6 = 26). Borrowing bits from the parent /22 prefix to create /26 subnets uses 2622=426 - 22 = 4 subnet bits, resulting in 24=162^4 = 16 total subnets.

Adım Adım Çözüm

1
Calculate the number of host bits required for 50 usable IP addresses
6 host bits are required
The formula for usable host IPs is 2h22^h - 2. With h=5h = 5, 252=302^5 - 2 = 30 hosts (insufficient). With h=6h = 6, 262=622^6 - 2 = 62 usable hosts, which satisfies the requirement of at least 50 hosts.
2
Determine the new subnet prefix length
The prefix length is /26
Subtracting the 6 host bits from the 32-bit IPv4 address space yields 326=2632 - 6 = 26.
3
Calculate the number of subnets derived from the parent /22 block
16 subnets
Subtracting the original prefix (/22) from the new prefix (/26) gives 2622=426 - 22 = 4 subnet bits. Borrowing 4 bits produces 24=162^4 = 16 subnets.

Anahtar Kavram

Subnet sizing and calculation of total subnets created using FLSM from a CIDR block.
Soru 1258Soru

Refer to the following routing table output from a Cisco router:

text
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2

Gateway of last resort is 10.1.1.1 to network 0.0.0.0

S* 0.0.0.0/0 [1/0] via 10.1.1.1
D 192.168.0.0/16 [90/307200] via 10.2.2.2, 01:45:12, GigabitEthernet0/0/1
O 192.168.4.0/24 [110/20] via 10.3.3.3, 00:12:34, GigabitEthernet0/0/2
S 192.168.4.128/26 [1/0] via 10.4.4.4
D 192.168.4.144/28 [90/281600] via 10.5.5.5, 00:05:10, GigabitEthernet0/0/3
O 192.168.4.148/30 [110/50] via 10.6.6.6, 00:01:20, GigabitEthernet0/0/4

The router receives an IP packet with a destination IP address of 192.168.4.150192.168.4.150. Which next-hop IP address will the router select to forward this packet, and for what reason?

Cevabı ve açıklamayı göster

Cevap: 10.6.6.6, because the 192.168.4.148/30 prefix provides the longest matching subnet mask for the destination address.

Cevap

The router selects next-hop 10.6.6.6 because 192.168.4.148/30 is the longest matching prefix for destination host 192.168.4.150.
When a router receives a packet, its forwarding engine determines the path by applying the Longest Prefix Match (LPM) rule. The destination address 192.168.4.150 matches multiple routes in the table (/16, /24, /26, /28, /30, and default /0). The route with prefix 192.168.4.148/30 has 30 matching bits, which is the most specific match. Administrative distance is only evaluated when a router receives routes for the exact same destination prefix length from different routing sources. Therefore, the packet is forwarded to next-hop 10.6.6.6.

Adım Adım Çözüm

1
Determine subnet boundaries for all matching routes in the routing table for IP address 192.168.4.150.
192.168.0.0/16 matches (192.168.0.0 - 192.168.255.255)
192.168.4.0/24 matches (192.168.4.0 - 192.168.4.255)
192.168.4.128/26 matches (192.168.4.128 - 192.168.4.191)
192.168.4.144/28 matches (192.168.4.144 - 192.168.4.159)
192.168.4.148/30 matches (192.168.4.148 - 192.168.4.151)
Identify all valid route entries in the Routing Information Base (RIB) that encompass the destination IP.
2
Compare prefix lengths among all matching entries.
Prefix lengths are /16, /24, /26, /28, and /30. The longest matching prefix length is /30.
Cisco routers use the Longest Prefix Match (LPM) rule to select the best route for packet forwarding.
3
Verify host IP validity within the selected /30 network.
Subnet 192.168.4.148/30 network address = 192.168.4.148, broadcast address = 192.168.4.151, usable host IP addresses = 192.168.4.149 and 192.168.4.150.
Confirming 192.168.4.150 is a valid unicast destination host IP within the /30 range.
4
Identify the next-hop IP associated with the longest matching route.
Route 192.168.4.148/30 points to next-hop IP 10.6.6.6 via interface GigabitEthernet0/0/4.
Administrative distance is only evaluated when identical prefixes are learned from multiple sources; since /30 is unique and longest, AD (110) is not compared against other prefixes.

Anahtar Kavram

Router Forwarding Decision Logic (Longest Prefix Match precedence over Administrative Distance and Metric)
Tahmini Süre:2m 0s
Soru 1259Soru

A network operations team configures the command `spanning-tree portfast` on access interface GigabitEthernet0/1 of a Cisco Catalyst switch. Which statement accurately describes the operational behavior of this interface when a link-up event occurs?

Cevabı ve açıklamayı göster

Cevap: The interface immediately transitions to the STP Forwarding state, bypassing the Listening and Learning states.

Cevap

The interface immediately transitions to the STP Forwarding state, bypassing the Listening and Learning states.
The correct answer states that the interface immediately transitions to the STP Forwarding state, bypassing the Listening and Learning states. This eliminates the standard 30-second STP timer delay (15 seconds Listening + 15 seconds Learning) when connecting end-user edge devices, allowing protocols like DHCP to succeed immediately upon physical link link-up.

Adım Adım Çözüm

1
Analyze standard 802.1D STP port state timers.
In traditional 802.1D STP, an interface transitions through Blocking → Listening (15s) → Learning (15s) → Forwarding, creating a total 30-second delay before traffic can be forwarded.
Understanding the baseline STP state progression highlights why end hosts experience initialization delays (such as DHCP timeouts).
2
Evaluate the specific function of Cisco STP PortFast.
PortFast allows edge ports connected directly to single workstations or servers to bypass the Listening and Learning states and enter Forwarding instantly.
End-user hosts do not create switching loops, so delaying their port activation serves no loop prevention purpose.
3
Confirm STP safeguards on PortFast interfaces.
STP is still active on the port and will send BPDUs. If another switch is plugged into a PortFast port, receipt of BPDUs or BPDU guard will protect the topology.
PortFast optimizes state transition speed without completely disabling Spanning Tree monitoring.

Anahtar Kavram

Cisco PortFast State Bypass and Operational Mechanics
Tahmini Süre:1m 0s
Soru 1260Soru

A network administrator is preparing to bundle the physical distribution system ports on a Cisco Wireless LAN Controller (WLC) to increase bandwidth and redundancy toward an upstream Cisco Catalyst switch stack. Which two requirements or operational characteristics apply when Link Aggregation (LAG) is enabled on the Cisco WLC?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The connected ports on the upstream switch must be combined into a single static EtherChannel bundle using the manual mode 'on'.; Enabling LAG merges all physical distribution system ports into a single logical interface, preventing the creation of multiple separate EtherChannel groups on the controller.

Cevap

The correct options are that the upstream switch ports must be configured into a static EtherChannel using mode 'on', and that enabling LAG merges all physical distribution system ports into a single logical interface on the controller.
Enabling LAG on a Cisco Wireless LAN Controller consolidates all physical distribution ports into a single logical EtherChannel. Because the controller does not use dynamic EtherChannel negotiation protocols like LACP or PAgP, the connected upstream switch ports must be manually configured in static EtherChannel mode using the 'channel-group <id> mode on' command.

Adım Adım Çözüm

1
Analyze Cisco WLC EtherChannel / LAG negotiation protocol requirements.
Cisco WLC LAG requires static frame distribution without LACP or PAgP signaling.
The WLC does not run LACP or PAgP daemons on its physical ports, requiring the connected switch ports to be set to static EtherChannel ('mode on').
2
Determine how physical ports are grouped when LAG is enabled on the controller.
All physical distribution system ports form one single logical bundle.
On a Cisco WLC, LAG is a global setting that combines all distribution ports into one single logical link bundle; multiple separate EtherChannel groups cannot be defined.
3
Evaluate AP behavior in Local mode vs FlexConnect mode upon WLC link bundle loss.
Local mode APs cease forwarding client traffic because they cannot switch traffic locally.
Local mode APs encapsulate all user data inside CAPWAP tunnels to the WLC. Local switching requires FlexConnect mode.

Anahtar Kavram

Cisco WLC Link Aggregation (LAG) Architecture and Trunking Requirements
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