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1987 soru

Tüm türler1,987Çoktan seçmeli1,020Çoklu seçim452Sayısal18Eşleştirme229Sıralama203Boşluk doldurma22Kısa cevap43
Soru 1461Soru →

A network administrator is categorizing Cisco Lightweight Access Point (LAP) operational modes to ensure appropriate deployment across enterprise campus and branch locations. Which AP mode on the left corresponds to each functional traffic handling and operational behavior on the right?

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Local Mode
FlexConnect Mode
Sniffer Mode
Rogue Detector Mode

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Local Mode corresponds to default CAPWAP central tunneling of all client traffic; FlexConnect Mode corresponds to local traffic switching and WAN failure resiliency for branch sites; Sniffer Mode corresponds to capturing raw 802.11 frames for packet analysis; Rogue Detector Mode corresponds to monitoring wired subnets to detect unauthorized AP connections.
Each Cisco LAP mode serves a specific operational role: Local mode is the default central-tunneling mode; FlexConnect mode allows local traffic switching at branch sites; Sniffer mode collects RF packet captures for troubleshooting; Rogue Detector mode checks the wired network to detect rogue APs physically connected to switches.

Adım Adım Çözüm

1
Analyze Centralized AP Operations
Local Mode is identified as the default LAP state where CAPWAP data and control tunnels carry all client frames to the WLC.
Campus deployments rely on central WLC data plane processing via Local mode.
2
Analyze Remote Branch AP Operations
FlexConnect Mode is identified as the mode designed for WAN-connected branch offices requiring local switching and standalone resilience.
FlexConnect avoids sending all branch user traffic across high-latency or low-bandwidth WAN links.
3
Differentiate Specialized Non-Client Servicing Modes
Sniffer Mode dedicates radios to capturing 802.11 air traffic for packet analyzers, while Rogue Detector Mode listens on wired networks to correlate rogue wireless MAC addresses.
Both modes cease servicing wireless clients to perform dedicated diagnostic or security functions.

Anahtar Kavram

Cisco Access Point Operating Modes and Traffic Handling
Tahmini Süre:1m 30s
Soru 1462Soru →

A network administrator is evaluating an OSPFv2 implementation across a shared Ethernet segment (172.16.1.0/24). Router R1 initialized first on the segment and assumed the Designated Router (DR) role. Routers R2 and R3 joined subsequently. Router R4 was added last, configured with an OSPF interface priority of 200, whereas R1, R2, and R3 retain the default interface priority of 1.

Executing `show ip ospf neighbor` on Router R4 produces the following output:

text
R4# show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 1 FULL/DR 00:00:36 172.16.1.1 GigabitEthernet0/1
2.2.2.2 1 FULL/BDR 00:00:34 172.16.1.2 GigabitEthernet0/1
3.3.3.3 1 FULL/DROTHER 00:00:38 172.16.1.3 GigabitEthernet0/1

Based on this output and OSPF operational behavior, why has Router R4 not assumed the Designated Router role despite having a higher interface priority?

Cevabı ve açıklamayı göster

Cevap: OSPF DR and BDR elections are non-preemptive; once an active DR is elected, a newly connected router will not trigger a election takeover even if configured with a higher priority.

Cevap

OSPF DR and BDR elections are non-preemptive; once an active DR is elected, a newly connected router will not trigger a election takeover even if configured with a higher priority.
OSPF DR and BDR election processes are strictly non-preemptive. Once a router is elected as Designated Router, it retains that position until its OSPF process reboots, its interface goes down, or the process is manually cleared. Bringing up a new router with a higher interface priority (such as 200) does not preempt the active DR.

Adım Adım Çözüm

1
Analyze the OSPF interface state and neighbor table output from Router R4.
Router R1 (Router ID 1.1.1.1) is serving as the active DR, and Router R2 (Router ID 2.2.2.2) is serving as the active BDR.
Both roles were established when R1 and R2 initially formed adjacencies on the 172.16.1.0/24 broadcast segment.
2
Evaluate the non-preemptive election mechanics of OSPFv2.
Even though Router R4 has an interface priority of 200 (which exceeds R1's priority of 1), OSPF does not preempt an existing DR or BDR.
Preemption would cause unnecessary LSA re-flooding and adjacency resets on multiaccess segments.
3
Determine how R4 could become the DR.
R4 will only become DR if the active DR and BDR fail, or if the OSPF routing processes on R1 and R2 are cleared/restarted.
Election procedures run only when the DR or BDR position becomes vacant.

Anahtar Kavram

Non-preemptive nature of OSPF DR/BDR elections on broadcast multiaccess networks
Tahmini Süre:2m 0s
Soru 1463Soru →

A network administrator is auditing interface configurations across an enterprise network. A host interface is assigned the IPv4 address 172.20.108.90172.20.108.90 with a subnet mask of 255.255.255.224255.255.255.224. Which IPv4 address represents the broadcast address for this subnetwork?

Cevabı ve açıklamayı göster

Cevap: 172.20.108.95172.20.108.95

Cevap

The broadcast address for the subnetwork is 172.20.108.95172.20.108.95.
For a /27/27 subnet mask (255.255.255.224255.255.255.224), the subnet block size is 256−224=32256 - 224 = 32. The subnets increment by 3232 in the fourth octet (0,32,64,96,1280, 32, 64, 96, 128). The host address 172.20.108.90172.20.108.90 falls into the subnet starting at 172.20.108.64172.20.108.64. The broadcast address is the highest IP address within this range, which is 172.20.108.95172.20.108.95 (one less than the next subnet ID of 172.20.108.96172.20.108.96).

Adım Adım Çözüm

1
Determine the CIDR prefix length and block size from the subnet mask.
The mask 255.255.255.224255.255.255.224 corresponds to a /27/27 prefix (24+324 + 3 bits). The block size in the fourth octet is 256−224=32256 - 224 = 32.
The subnet mask defines the boundary between the network and host portions of the IP address.
2
Identify the network ID for the given IP address.
Subnet multiples of 3232 in the fourth octet are 0,32,64,96,128...0, 32, 64, 96, 128... Since 9090 lies between 6464 and 9595, the network ID is 172.20.108.64172.20.108.64.
The network ID is the lowest address in the subnet block.
3
Calculate the broadcast address.
The next subnet starts at 172.20.108.96172.20.108.96. Subtracting 11 from the next network ID yields the broadcast address 172.20.108.95172.20.108.95.
The broadcast address is always the last address in the subnet range where all host bits are set to 1.

Anahtar Kavram

IPv4 Subnet Boundaries and Broadcast Address Calculation
Tahmini Süre:1m 0s
Soru 1464Soru →

During the OSPFv2 ExStart neighbor state, routers exchange initial Database Description (DBD) packets to establish a master-slave relationship. Which router attribute is compared to elect the master router?

Cevabı ve açıklamayı göster

Cevap: Router ID; OSPF Router ID; router id; Router-ID; router-id; The Router ID; the router id

Cevap

Router ID (the router with the numerically higher OSPF Router ID is elected as the master).
In the OSPF ExStart neighbor state, routers exchange empty Database Description (DBD) packets to decide which router controls the packet sequence numbers (the master). The router with the higher OSPF Router ID is elected master.

Adım Adım Çözüm

1
Identify the neighbor state and process described in the prompt.
The scenario refers to the ExStart state where routers negotiate master/slave roles using DBD packets.
ExStart is designed to establish sequence numbers and determine control over database exchange.
2
Determine the parameter used to break ties and elect the master router.
The router with the higher OSPF Router ID is selected as the master.
OSPF specifies that the router possessing the highest Router ID acts as master to initiate DBD sequence numbering.

Anahtar Kavram

OSPFv2 Master/Slave Election during ExStart State
Soru 1465Soru →

Match each OSPFv2 network type on the left to its correct DR/BDR election requirement and default Hello timer on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Broadcast Multiaccess
Point-to-Point
Point-to-Multipoint

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Broadcast Multiaccess matches with 'Elects DR/BDR; default Hello timer is 10 seconds'. Point-to-Point matches with 'Does NOT elect DR/BDR; default Hello timer is 10 seconds'. Point-to-Multipoint matches with 'Does NOT elect DR/BDR; default Hello timer is 30 seconds'.
Broadcast Multiaccess networks use a 10-second Hello timer and perform DR/BDR elections to manage multiaccess adjacencies. Point-to-Point networks use a 10-second Hello timer but suppress DR/BDR elections because only two endpoints exist. Point-to-Multipoint networks suppress DR/BDR elections and operate with a 30-second Hello timer.

Adım Adım Çözüm

1
Determine DR/BDR election requirements for each OSPFv2 network type.
DR/BDR elections only occur on multiaccess media (Broadcast and Non-Broadcast Multiaccess). Point-to-Point and Point-to-Multipoint types bypass DR/BDR elections.
DR/BDR selection prevents unnecessary adjacency overhead on multiaccess networks.
2
Recall default OSPFv2 Hello timers for each network type.
Broadcast and Point-to-Point network types default to 10-second Hello timers. Non-Broadcast and Point-to-Multipoint default to 30-second Hello timers.
OSPF timer defaults depend on whether the underlying physical medium is considered high-speed broadcast/point-to-point or slower non-broadcast media.
3
Match the attributes of each network type.
Broadcast Multiaccess -> DR/BDR elected, 10s Hello. Point-to-Point -> No DR/BDR, 10s Hello. Point-to-Multipoint -> No DR/BDR, 30s Hello.
Combines the DR/BDR requirement with the appropriate interface default Hello timer.

Anahtar Kavram

OSPFv2 Network Types, DR/BDR Selection, and Default Timers
Tahmini Süre:1m 30s
Soru 1466Soru →

A network administrator intends to configure a floating static route on Router R1 to serve as a backup to a primary route dynamically learned via OSPF (Administrative Distance 110) for destination network 172.16.50.0/24172.16.50.0/24. However, while the primary OSPF link remains healthy and operational, the administrator observes that the newly added static route immediately overrides the OSPF route in the IPv4 routing table. Which command did the administrator incorrectly execute on Router R1?

Cevabı ve açıklamayı göster

Cevap: ip route 172.16.50.0 255.255.255.0 192.168.1.2 90

Cevap

The command 'ip route 172.16.50.0 255.255.255.0 192.168.1.2 90' was incorrectly configured because assigning an Administrative Distance lower than 110 causes the static route to immediately preempt the primary OSPF path.
In Cisco IOS, static routes have a default Administrative Distance (AD) of 1. A floating static route acts as a backup path and must be configured with an AD higher than the primary route's protocol AD. Because OSPF has a default AD of 110, setting the static route's AD to 90 gives it higher priority (lower AD number) than OSPF. Consequently, the router immediately installs the static route into the routing table and ignores the active OSPF route.

Adım Adım Çözüm

1
Analyze the requirement for a floating static route.
A floating static route must have an Administrative Distance (AD) higher than the primary routing protocol so that it remains inactive in the routing table until the primary route fails.
Cisco IOS routing logic selects paths based on the lowest Administrative Distance first.
2
Compare the AD of the primary route (OSPF) against the attempted static route.
OSPF has a default AD of 110. To act as a backup, the static route AD must be greater than 110 (such as 120).
If the static route is configured with an AD lower than 110 (such as 90), the router prefers the static route over the OSPF route.
3
Identify which misconfiguration caused the immediate routing table override.
The command specifying an AD of 90 is preferred over OSPF's AD of 110, causing immediate installation into the routing table.
Lower AD numbers indicate higher trustworthiness in Cisco IOS.

Anahtar Kavram

Floating Static Route Administrative Distance Selection
Soru 1467Soru →

A network engineer is configuring OSPFv2 on two directly connected routers. Which TWO parameters must match identically in the OSPF Hello packets exchanged between the routers for a neighbor adjacency to form successfully? (Select TWO.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Area ID; Hello and Dead timer intervals

Cevap

The parameters that must match identically in OSPF Hello packets are the Area ID and the Hello and Dead timer intervals.
For two OSPFv2 routers to form an adjacency, they must agree on key interface configuration parameters transmitted in Hello packets. Both the Area ID and the Hello/Dead timer intervals are mandatory matching fields. If any of these fields differ, the routers will ignore or drop the Hello packets and remain unable to form a neighbor relationship.

Adım Adım Çözüm

1
Analyze OSPF Hello packet fields required for neighbor adjacency formation.
Identify parameters carried in Hello packets that undergo validation upon receipt.
OSPF routers verify specific fields in incoming Hello packets before allowing neighbor state transitions.
2
Evaluate mandatory matching parameters versus non-matching parameters.
Area ID and Hello/Dead timer intervals must match. Router IDs must be unique, and Process IDs are locally significant only.
Matching Area IDs ensure routers agree on network membership, and matching timers maintain synchronized keepalive expectations.

Anahtar Kavram

OSPFv2 Neighbor Adjacency Requirements
Soru 1468Soru →

A network administrator is configuring a new Wireless LAN (WLAN) for guest client connectivity on a Cisco Wireless LAN Controller (WLC) using the GUI. Arrange the administrative steps in the correct chronological sequence from first to last to properly configure and enable the WLAN.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct chronological sequence is: 1) Navigate to WLANs and select 'Create New', 2) Define Profile Name, SSID, and ID, 3) Map the dynamic interface under the General tab, 4) Configure Layer 2 security settings under the Security tab, and 5) Enable the WLAN Status checkbox under the General tab and Apply.
The proper administrative workflow in Cisco AireOS WLC GUI begins with creating the WLAN container ('Create New'). Next, the administrator assigns identity parameters (Profile Name and SSID). Once created, the administrator binds the WLAN to its dynamic interface under the General tab, configures Layer 2 security parameters under the Security tab, and finally checks the Status checkbox under the General tab to enable the network for client association.

Adım Adım Çözüm

1
Navigate to the WLANs menu in the Cisco WLC GUI.
Access the WLAN configuration index page.
Choosing 'Create New' initiates the wizard to instantiate a new WLAN ID.
2
Input the Profile Name and SSID, then click Apply.
The WLC creates the WLAN profile instance.
Basic naming attributes are required before sub-tab parameters become editable.
3
Select the target dynamic interface/VLAN on the General tab.
Wireless client traffic on this WLAN is mapped to the selected network interface.
Interface binding ensures clients receive IP addresses from the correct subnet.
4
Select the Security tab and define Layer 2 security settings (e.g., WPA2/WPA3 PSK or 802.1X).
Encryption and authentication policies are bound to the WLAN.
Wireless clients must authenticate using matching security parameters to join.
5
Return to the General tab, check the Status box, and click Apply.
The WLAN state changes to Enabled.
WLANs are created in a disabled state by default to prevent client association during configuration.

Anahtar Kavram

Cisco WLC GUI WLAN Provisioning Lifecycle
Tahmini Süre:1m 30s
Soru 1469Soru →

A Cisco router interface with MAC address 0011.4567.89ab is configured to dynamically derive its IPv6 interface identifier using EUI-64. What is the resulting 64-bit interface identifier in standard colon-separated hexadecimal IPv6 format?

Cevabı ve açıklamayı göster

Cevap: 0211:45ff:fe67:89ab; 211:45ff:fe67:89ab

Cevap

0211:45ff:fe67:89ab
To derive a 64-bit IPv6 interface identifier from the 48-bit MAC address 0011.4567.89ab using EUI-64: 1) Insert FFFE into the middle of the MAC address, yielding 0011:45FF:FE67:89AB. 2) Invert the 7th bit (Universal/Local bit) of the first octet. The first octet 0x00 (0000 0000 in binary) becomes 0x02 (0000 0010 in binary). Combining these steps yields the final interface identifier 0211:45ff:fe67:89ab (or 211:45ff:fe67:89ab without leading zero).

Adım Adım Çözüm

1
Split the 48-bit MAC address into two 24-bit halves.
First half: 00:11:45, Second half: 67:89:ab
EUI-64 calculation begins by separating the Organizationally Unique Identifier (OUI) from the vendor-assigned NIC portion.
2
Insert the 16-bit hexadecimal string FFFE between the two halves.
0011:45FF:FE67:89AB
IEEE EUI-64 conversion requires expanding the 48-bit MAC address into a 64-bit value by inserting FFFE at the midpoint.
3
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 0x00 (binary 00000000) becomes 0x02 (binary 00000010), producing 0211:45ff:fe67:89ab.
Inverting the U/L bit sets it to 1, indicating that the IEEE MAC-derived interface ID is globally unique.

Anahtar Kavram

IPv6 EUI-64 Interface Identifier Derivation
Soru 1470Soru →

Match each Layer 2 discovery protocol characteristic or configuration parameter on the left with its corresponding description or default value on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

IEEE 802.1AB
CDP default holdtime
LLDP default reinitialization delay
lldp run

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

IEEE 802.1AB matches the open vendor-neutral standard specification for LLDP. CDP default holdtime matches 180 seconds. LLDP default reinitialization delay matches 2 seconds. 'lldp run' matches the global configuration command used to enable LLDP on a Cisco switch.
IEEE 802.1AB is the official open standard defining LLDP. CDP defaults to an advertisement interval of 60 seconds and a holdtime of 180 seconds. The LLDP reinitialization delay defaults to 2 seconds on Cisco switches. Enabling LLDP globally requires the 'lldp run' global configuration command.

Adım Adım Çözüm

1
Identify the standard governing LLDP.
IEEE 802.1AB is the formal IEEE standard for LLDP, distinguishing it from Cisco proprietary CDP.
Knowledge of protocol standardization helps determine multi-vendor interoperability.
2
Determine the default CDP timer values.
CDP sends advertisements every 60 seconds and maintains a holdtime of 180 seconds by default.
Timer parameters ensure neighbor records persist across three missed advertisement intervals.
3
Identify default LLDP operational timers.
The LLDP reinitialization delay (lldp reinit) defaults to 2 seconds, which delays LLDP initialization on an interface after a state change.
Understanding default timer settings is critical for troubleshooting protocol behavior and flapping links.
4
Verify global configuration syntax for LLDP activation.
The command 'lldp run' enables LLDP globally on Cisco IOS switches.
LLDP is disabled by default on some Cisco platforms or software versions, requiring global activation before interface commands take effect.

Anahtar Kavram

Layer 2 Discovery Protocol Standards, Timers, and Configuration Commands
Tahmini Süre:1m 30s
Soru 1471Soru →

An enterprise router receives its default route via an eBGP session established with ISP-A. A network administrator attempts to configure a secondary floating static backup default route pointing to ISP-B using the following command:

`ip route 0.0.0.0 0.0.0.0 198.51.100.2 15`

Assuming the eBGP session remains active and continues advertising the default route, which outcome will occur on the router?

Cevabı ve açıklamayı göster

Cevap: The static route will immediately enter the routing table and replace the eBGP default route as the primary path.

Cevap

The static route will immediately enter the routing table and replace the eBGP default route as the primary path.
In Cisco IOS, route selection between different protocol sources is determined by Administrative Distance (AD), where lower values are preferred. The default AD for External BGP (eBGP) is 20. Because the engineer configured the static route with an AD of 15, the router considers the static path more trustworthy than the eBGP path (15<2015 < 20). Consequently, the static route immediately takes precedence in the routing table, failing to function as a floating backup.

Adım Adım Çözüm

1
Identify the default administrative distance (AD) of the primary routing source.
External BGP (eBGP) has a default administrative distance of 20.
Cisco IOS assigns specific default AD values to judge route trustworthiness among different routing sources.
2
Compare the configured static route AD against the primary route's AD.
The configured static route AD is 15, which is lower than the eBGP AD of 20 (15<2015 < 20).
Lower administrative distance values indicate higher trustworthiness in Cisco IOS forwarding selection logic.
3
Determine which route is installed into the routing table.
The static route with AD 15 overrides the eBGP route with AD 20 and is actively installed into the routing table.
To create a valid floating static backup, the backup route's AD must be strictly greater than the primary route's AD (e.g., AD > 20).

Anahtar Kavram

Floating Static Route Administrative Distance Requirements
Tahmini Süre:1m 30s
Soru 1472Soru →

An engineer is configuring a fully specified IPv6 static route on a Cisco router to forward traffic destined for 2001:db8:abc:33::/642001:\text{db8}:\text{abc}:33::/64. What local interface keyword completes the command syntax when using the next-hop link-local address fe80::cafe\text{fe80}::\text{cafe} via interface GigabitEthernet0/0/2?

Aşağıdaki boşlukları doldurun

Router(config)# ipv6 route 2001:db8:abc:33::/64 fe80::cafe
Cevabı ve açıklamayı göster

Cevap

GigabitEthernet0/0/2 (or Gi0/0/2)
When configuring an IPv6 static route with a link-local next-hop address, Cisco IOS requires the local exit interface (GigabitEthernet0/0/2) to precede the link-local IPv6 address. Without the exit interface, the router cannot determine which local link reaches the specified link-local address.

Adım Adım Çözüm

1
Identify the mandatory components of a link-local IPv6 static route in Cisco IOS.
When a link-local address (FE80::/10) is specified as the next hop, Cisco IOS requires the local exit interface to be included preceding the next-hop address.
Link-local addresses are non-routable and exist independently on every link, making them ambiguous without specifying the outbound local interface.
2
Complete the command syntax.
The proper command structure is 'ipv6 route <destination-prefix/prefix-length> <exit-interface> <link-local-address>'. Inserting GigabitEthernet0/0/2 into {{blank_1}} correctly specifies the route.
This provides both interface scope and next-hop link-local identification.

Anahtar Kavram

Fully specified IPv6 static routes with link-local next hops
Soru 1473Soru →

A network administrator is configuring interface FastEthernet0/18 on switch SW-2 to connect an end-user workstation in VLAN 75. The interface must be explicitly set to access mode and assigned to VLAN 75. Which two commands must be entered in interface configuration mode to complete this setup? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: switchport mode access; switchport access vlan 75

Cevap

To configure a switch port for end-device access connectivity, the engineer must statically set the port mode to access using 'switchport mode access' and assign it to the designated VLAN using 'switchport access vlan 75'.
Proper access port configuration requires two explicit commands in interface configuration mode: 'switchport mode access' to define the port as a static access port, and 'switchport access vlan 75' to assign it to VLAN 75.

Adım Adım Çözüm

1
Set the administrative mode of the interface to access.
The interface is forced into access mode and will not negotiate trunking.
Ensures the port operates strictly as a single-VLAN access port.
2
Assign the access port to VLAN 75.
The interface becomes a member of VLAN 75.
Associates untagged frames received on FastEthernet0/18 with broadcast domain VLAN 75.

Anahtar Kavram

Access Port VLAN Assignment
Soru 1474Soru →

A network engineer is auditing an enterprise switch network operating with Rapid PVST+. Which two statements correctly describe the port roles and operational mechanisms of Rapid PVST+? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: An Alternate port serves as a backup path toward the Root Bridge and can immediately transition to the Root Port role if the active Root Port fails.; A Backup port provides redundant connectivity to a shared segment where another port on the same local switch is functioning as the Designated port.

Cevap

The correct statements are that an Alternate port serves as a backup path toward the Root Bridge and can transition immediately upon root port failure, and that a Backup port provides redundant connectivity to a shared segment where another port on the same switch is the Designated port.
Rapid PVST+ defines explicit port roles to achieve rapid convergence. An Alternate port provides a backup path to the root bridge and takes over immediately if the root port fails. A Backup port provides a redundant link to a shared collision domain where another interface on the same switch is already the designated port.

Adım Adım Çözüm

1
Evaluate the definition and convergence behavior of Rapid PVST+ Alternate ports.
Alternate ports receive BPDUs from other switches and act as backup root paths, transitioning immediately to root ports without forwarding delays during failures.
Rapid PVST+ optimizes convergence by allowing pre-calculated alternate paths to become root ports instantaneously.
2
Evaluate the definition and function of Rapid PVST+ Backup ports.
Backup ports receive BPDUs from another interface on the exact same switch on a shared medium where the local switch is designated.
This redundant port role specifically addresses self-loop scenarios on shared collision domains.
3
Verify bridge priority calculation rules for Rapid PVST+.
Configurable base priorities must be multiples of 4096 due to the 4-bit priority portion of the extended bridge ID.
Increments of 1024 are invalid and will be rejected by Cisco IOS CLI.
4
Analyze PortFast placement guidelines and Rapid PVST+ handshake mechanics.
Proposal-agreement handshakes function on point-to-point links automatically; PortFast is restricted to edge ports.
Misconfiguring PortFast on trunks bypasses standard loop protection mechanisms.

Anahtar Kavram

Rapid PVST+ Port Roles and Operational Characteristics
Soru 1475Soru →

A network administrator needs to perform the initial configuration on a new Cisco Catalyst switch via an out-of-band management session. The administrator connects a laptop terminal emulator directly to the RJ-45 console port of the switch using an RS-232 serial cable adapter. Which cable pinout scheme is required to correctly map the laptop terminal adapter signals to the switch console interface?

Cevabı ve açıklamayı göster

Cevap: A rollover cable pinout where pin 1 on one connector connects to pin 8 on the opposite connector.

Cevap

A rollover cable pinout (where pin 1 connects to pin 8, pin 2 to pin 7, etc.) is required to connect a terminal serial interface to a Cisco switch RJ-45 console port.
Cisco RJ-45 console ports require a rollover cable (often called a console cable). In a rollover cable, the pinout on one end is completely inverted relative to the other end—pin 1 maps to pin 8, pin 2 maps to pin 7, pin 3 maps to pin 6, and pin 4 maps to pin 5. When combined with an RS-232 terminal adapter (DB-9 or USB-to-serial), this pin inversion routes the laptop serial transmitter pin to the console receiver pin and vice versa.

Adım Adım Çözüm

1
Identify the type of connection being established.
The connection is an out-of-band management terminal connection between a host PC/laptop terminal adapter and an RJ-45 Cisco console port, not an Ethernet network data link.
Console management uses asynchronous RS-232 serial signalling over an RJ-45 physical port interface rather than standard Ethernet framing.
2
Determine the physical pin mapping for Cisco RJ-45 console interfaces.
Cisco console ports use a rollover pinout convention where the wire sequence completely reverses from one RJ-45 connector to the other end (Pin 1 to Pin 8, Pin 2 to Pin 7, Pin 3 to Pin 6, Pin 4 to Pin 5).
This reversal correctly aligns the Transmit Data (TxD), Receive Data (RxD), and Ground signals between the RJ-45 console port and the DB-9 / USB serial adapter attached to the management PC.

Anahtar Kavram

Cisco Console Port and Rollover Cable Pinouts
Soru 1476Soru →

A network engineer is configuring IPv4 static routes on a Cisco IOS router. Which TWO statements accurately describe the characteristics and syntax of Cisco IPv4 static routing? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: A floating static route must be configured with an administrative distance higher than the administrative distance of the primary route.; Static routes configured pointing directly to a point-to-point exit interface do not require a recursive lookup to resolve the next-hop IP address.

Cevap

The two correct statements state that a floating static route requires an administrative distance higher than the primary route, and that static routes pointing to a point-to-point exit interface bypass recursive lookup.
Floating static routes rely on having a higher administrative distance than the primary route so they stay out of the routing table until the primary route fails. Additionally, specifying a point-to-point exit interface allows direct frame transmission without a recursive next-hop lookup.

Adım Adım Çözüm

1
Evaluate the administrative distance requirement for floating static routes.
Floating static routes are designed as backup routes. Routers prefer lower administrative distance (AD) values. Therefore, a floating static route must have a higher AD than the primary route to remain inactive until the primary route fails.
Lower AD indicates higher trustworthiness in Cisco IOS forwarding decisions.
2
Analyze how next-hop resolution works with point-to-point exit interfaces.
Specifying a point-to-point exit interface resolves the egress interface immediately without needing a second (recursive) lookup for a next-hop IP address.
Point-to-point links have only one destination on the link, so the router knows directly where to send frames.
3
Verify incorrect distractor statements.
Setting an AD of 10 for a backup to EIGRP (AD 90) makes the static route active immediately, overriding EIGRP instead of floating behind it. Additionally, static route syntax uses subnet masks, not wildcard masks.
Wildcard masks are syntax elements of ACLs/OSPF, not Cisco IOS 'ip route' commands.

Anahtar Kavram

IPv4 Static Route Syntax and Floating Static Route Principles
Soru 1477Soru →

A Cisco router is running OSPFv2 with an active Loopback 0 interface (10.10.10.1/32) and a GigabitEthernet0/0 interface (192.168.1.1/24). No explicit router ID command was configured under the OSPF process, so OSPF selected 10.10.10.1 as the Router ID when the process initialized. A network engineer subsequently configures a new Loopback 1 interface with IP address 172.16.100.1/32 and brings it into an operational up/up state. Which statement accurately describes the status of the OSPF Router ID immediately after Loopback 1 is brought up?

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Cevap: The OSPF Router ID remains 10.10.10.1 until the OSPF process is restarted or the router is reloaded.

Cevap

The OSPF Router ID remains 10.10.10.1 until the OSPF process is restarted or the router is reloaded.
OSPF Router ID selection is non-preemptive. Once the OSPF routing process selects a Router ID at startup (10.10.10.1 from the active Loopback 0), it retains that Router ID even if another interface with a higher IP address (such as Loopback 1 at 172.16.100.1) is subsequently configured and brought up. The new Router ID will only take effect if the OSPF process is manually reset (using 'clear ip ospf process') or if the router is rebooted.

Adım Adım Çözüm

1
Determine initial OSPF Router ID election outcome.
OSPF selected 10.10.10.1 because Loopback 0 was the highest IP active loopback interface when the OSPF process initialized.
OSPF follows election precedence: manual 'router-id' command > highest IP among active loopbacks > highest IP among active physical interfaces.
2
Analyze OSPF Router ID election behavior upon configuration changes.
The OSPF process maintains its currently active Router ID and does not preempt it when a new interface with a higher IP address is brought up.
Router ID stability prevents unnecessary SPF recalculations and neighbor adjacency resets. A process restart (e.g., using 'clear ip ospf process') is required to force re-election.

Anahtar Kavram

OSPFv2 Router ID Non-Preemptive Election Logic
Soru 1478Soru →

A Cisco router starts an OSPFv2 process without an explicitly configured router ID using the 'router-id' command. The router has the following active interfaces:

- Loopback 0: 10.1.1.1/32
- Loopback 1: 10.2.2.2/32
- GigabitEthernet 0/0: 172.16.10.1/24
- GigabitEthernet 0/1: 192.168.1.1/24

Which IPv4 address will OSPFv2 select as the router ID?

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Cevap: 10.2.2.2

Cevap

10.2.2.2
When no manual router ID is specified via the 'router-id' command, OSPFv2 selects the highest IPv4 address of any active loopback interface. Between Loopback 0 (10.1.1.1) and Loopback 1 (10.2.2.2), 10.2.2.2 is the higher IP address and is selected as the Router ID.

Adım Adım Çözüm

1
Check for an explicitly configured router ID
No explicit 'router-id' command has been configured.
Explicit configuration takes top priority in OSPF router ID selection.
2
Evaluate active loopback interfaces
Two active loopbacks exist: 10.1.1.1 and 10.2.2.2.
Loopback interfaces take precedence over physical interfaces.
3
Select the highest IPv4 address among active loopback interfaces
10.2.2.2 is higher than 10.1.1.1, making 10.2.2.2 the chosen OSPF Router ID.
When multiple loopbacks are present, OSPF breaks the tie using the highest IPv4 address.

Anahtar Kavram

OSPFv2 Router ID Selection Priority
Soru 1479Soru →

An enterprise router R1 learns the path to a remote branch subnet 10.150.0.0/1610.150.0.0/16 via Internal EIGRP, which has a default administrative distance of 9090. A network engineer intends to configure a secondary floating static route via next-hop IP 192.168.99.2192.168.99.2 to serve strictly as a backup path when EIGRP fails. However, the engineer enters the following command on R1:

`ip route 10.150.0.0 255.255.0.0 192.168.99.2 85`

Which two statements correctly describe the operational impact of this configuration? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The newly configured static route will immediately enter the Routing Information Base (RIB) and displace the EIGRP route as the active path.; To function correctly as a floating static backup route, the static route's administrative distance must be configured with a value greater than 90.

Cevap

The static route will immediately enter the routing table and displace the EIGRP route because its assigned administrative distance (85) is lower than Internal EIGRP (90). To act as a backup floating static route, its administrative distance must be set to a value greater than 90.
Cisco routers select routes from different routing sources based on Administrative Distance (AD), where lower AD values indicate higher preference. Internal EIGRP has a default AD of 90. Because the static route command explicitly defines an AD of 85, the static route is considered more trustworthy than EIGRP and is immediately placed into the routing table. To function properly as a floating static route, the static route must have an AD set higher than the primary route's AD (greater than 90) so it remains inactive until the primary EIGRP route vanishes.

Adım Adım Çözüm

1
Identify the administrative distance of the primary route protocol.
Internal EIGRP has a default Administrative Distance (AD) of 90.
Administrative Distance defines the trustworthiness of a routing information source in Cisco IOS.
2
Analyze the configured static route's administrative distance parameter.
The command `ip route 10.150.0.0 255.255.0.0 192.168.99.2 85` explicitly assigns an AD of 85 to the static route.
The trailing numeric argument in the `ip route` syntax overrides the default static route AD of 1.
3
Compare administrative distances to determine routing table (RIB) selection.
Since 85<9085 < 90, the static route wins route selection over Internal EIGRP and is immediately installed into the RIB as the active route.
Lower AD values are strictly preferred over higher AD values.
4
Determine the necessary administrative distance for floating static functionality.
To float (remain inactive until the EIGRP path fails), the static route must be configured with an AD value strictly greater than 90 (e.g., 95, 130).
Floating static routes rely on a higher AD so they are suppressed while the lower-AD primary route is present in the routing table.

Anahtar Kavram

Floating Static Route Administrative Distance Selection
Soru 1480Soru →

A network administrator configures a Cisco Catalyst switch running Rapid PVST+ by setting the base bridge priority for VLAN 25 to 1638416384 using the command `spanning-tree vlan 25 priority 16384`. Which value represents the exact priority component of the Bridge Identifier (BID) transmitted in BPDUs by this switch for VLAN 25?

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Cevap: 1640916409

Cevap

The correct priority component in the BID is 1640916409, calculated by adding the configured base priority of 1638416384 and the VLAN ID extension of 2525.
Rapid PVST+ implements 802.1t System ID Extension, dividing the traditional 16-bit priority field into a 4-bit Priority field (multiples of 4096) and a 12-bit System ID Extension containing the VLAN ID. When a switch transmits BPDUs for VLAN 25 with a base priority of 1638416384, the actual BID priority header value becomes 16384+25=1640916384 + 25 = 16409.

Adım Adım Çözüm

1
Identify the base priority and System ID Extension configured for the VLAN.
Base Priority = 1638416384, System ID Extension = 2525 (VLAN 25).
Rapid PVST+ uses the 12-bit System ID Extension to embed the VLAN ID into the Bridge Identifier structure.
2
Calculate the total BID priority value.
16384+25=1640916384 + 25 = 16409.
The total bridge priority field encoded into BPDUs is the sum of the 4-bit base priority prefix and the 12-bit VLAN identifier.

Anahtar Kavram

Rapid PVST+ System ID Extension and Bridge Identifier (BID) Calculation
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