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Tüm alıştırma soruları

1987 soru

Tüm türler1,987Çoktan seçmeli1,020Çoklu seçim452Sayısal18Eşleştirme229Sıralama203Boşluk doldurma22Kısa cevap43
Soru 121Soru →

Match each Cisco IOS interface status or error counter symptom to its corresponding physical or data-link troubleshooting root cause.

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Öğeler

High number of late collisions recorded on a half-duplex configured interface
High number of CRC / FCS error counters increasing on the interface
Interface state shows 'GigabitEthernet0/1 is up, line protocol is down'
Interface state shows 'FastEthernet0/1 is administratively down, line protocol is down'

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Late collisions match duplex mismatch; CRC errors match physical cable corruption or noise; Interface up / line protocol down matches Layer 2 encapsulation mismatch; Interface administratively down matches the interface being disabled with the shutdown command.
Matching interface symptoms correctly pairs late collisions with duplex mismatches, CRC error increments with physical cabling damage or electrical noise, 'up/down' status with Layer 2 framing/encapsulation issues, and 'administratively down' status with the interface shutdown configuration command.

Adım Adım Çözüm

1
Examine the Layer 1 physical symptoms and Cisco IOS interface counters.
Differentiate between physical layer errors (CRC, late collisions), interface operational states (up/down), and administrative states (administratively down).
Each Cisco IOS interface statistic isolates specific Layer 1 or Layer 2 network faults.
2
Map each interface symptom to its underlying root cause.
Pair late collisions with duplex mismatch, CRC errors with cable/interference issues, up/down line protocol with encapsulation/keepalive failures, and administratively down with the shutdown command.
Accurate pairing ensures effective troubleshooting of physical and data link layer issues.

Anahtar Kavram

Cisco IOS Interface Troubleshooting and Diagnostics
Soru 122Soru →

Match each enterprise network infrastructure component on the left with its primary operational function and architectural role on the right.

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Öğeler

Next-Generation Firewall (NGFW)
Wireless LAN Controller (WLC)
Type 1 Hypervisor Virtual Switch
Layer 3 Access Switch

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Next-Generation Firewall matches deep packet inspection up to Layer 7; Wireless LAN Controller matches centralized access point provisioning and RF management; Type 1 Hypervisor Virtual Switch matches bridging vNICs to physical network interfaces on bare metal; Layer 3 Access Switch matches hardware-based ASIC inter-VLAN packet forwarding.
Each network component is correctly paired with its defining enterprise function: Next-Generation Firewalls perform deep packet inspection up to Layer 7; Wireless LAN Controllers manage centralized AP configurations, radio frequencies, and roaming; Type 1 Hypervisor Virtual Switches bridge virtual machine vNICs directly on bare-metal hardware; and Layer 3 Access Switches utilize dedicated ASICs for wire-speed inter-VLAN packet routing.

Adım Adım Çözüm

1
Identify the primary operational scope of enterprise security appliances.
Determine that Next-Generation Firewalls (NGFW) inspect packet payloads through Layer 7 to provide application identification, IPS functionality, and threat prevention.
Traditional firewalls evaluate only Layer 3 and Layer 4 headers, whereas NGFWs integrate deep packet inspection at Layer 7.
2
Analyze centralized management functions for campus wireless networks.
Recognize that Wireless LAN Controllers (WLC) serve as central control points for Lightweight Access Points (LAPs), handling channel management, transmit power, and client roaming coordination.
Cisco split-MAC architecture places real-time MAC functions on the LAP and management/control functions on the WLC.
3
Evaluate hypervisor types and virtual networking architectures.
Determine that a Type 1 Hypervisor operates natively on physical hardware without a host OS, using embedded virtual switches to interconnect vNICs to physical NIC uplinks.
Type 1 bare-metal hypervisors bypass consumer operating system overhead, presenting direct hardware interfaces to virtual switches.
4
Examine high-speed LAN switching and routing mechanisms.
Identify that Layer 3 switches use Application-Specific Integrated Circuits (ASICs) to forward IP packets between VLANs at line rate.
Layer 3 switches combine traditional switch port density with dedicated routing ASICs to remove software routing bottlenecks.

Anahtar Kavram

Roles, operational layers, and architectural responsibilities of primary enterprise network components.
Soru 123Soru →

Match each Cisco IOS interface status or error symptom on the left to its most probable underlying root cause on the right.

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Öğeler

Interface is down, line protocol is down
Interface is up, line protocol is down
Interface is administratively down, line protocol is down
Interface is up, line protocol is up (with rapidly incrementing late collisions)

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Interface down/down matches physical Layer 1 failure; Interface up/down matches Layer 2 encapsulation or keepalive failure; Interface administratively down matches manual shutdown command; Interface up/up with late collisions matches duplex mismatch.
Interface diagnostic states directly correlate with specific OSI layers and configurations: physical cable disconnects cause 'down/down'; Layer 2 framing errors cause 'up/down'; the 'shutdown' command displays 'administratively down'; and late collisions on an active link indicate a duplex mismatch.

Adım Adım Çözüm

1
Analyze 'Interface is down, line protocol is down'.
Identified physical Layer 1 signal loss.
When electrical/optical carrier signal is missing due to a disconnected or broken cable, both status and line protocol report down.
2
Analyze 'Interface is up, line protocol is down'.
Identified Layer 2 protocol/framing failure.
Physical carrier (Layer 1) is detected, but Data Link layer communication failed due to mismatched encapsulation or lost keepalives.
3
Analyze 'Interface is administratively down, line protocol is down'.
Identified manual administrative disablement.
This explicit status string appears only when an administrator applies the 'shutdown' configuration command.
4
Analyze 'Interface is up, line protocol is up (with rapidly incrementing late collisions)'.
Identified duplex mismatch error pattern.
Late collisions occur when an interface set to half-duplex transmits while a full-duplex remote end transmits without checking for collisions past the slot time window.

Anahtar Kavram

Cisco IOS Interface Status Diagnostics and Troubleshooting
Soru 124Soru →

A network administrator is establishing a backup default route on a Cisco IOS router. The primary default route is currently learned dynamically via OSPFv3 with an administrative distance of 110. The administrator wants to ensure that the backup path towards the next-hop global unicast address 2001:db8:200::2 is used only if the primary OSPFv3 route fails. Which command correctly achieves this objective?

Cevabı ve açıklamayı göster

Cevap: ipv6 route ::/0 2001:db8:200::2 130

Cevap

ipv6 route ::/0 2001:db8:200::2 130
The correct command uses the IPv6 default route prefix ::/0, targets the global unicast next-hop address, and assigns an administrative distance of 130 (which is greater than OSPFv3's AD of 110), successfully floating the route until the primary path fails.

Adım Adım Çözüm

1
Identify the IPv6 default route prefix notation.
The IPv6 default route representation is ::/0.
IPv6 default routes represent all possible destination IPv6 networks using the all-zeros prefix with a length of zero.
2
Determine the required administrative distance for a floating static route.
Set an administrative distance higher than 110 (e.g., 130).
A floating static route must have an administrative distance higher than the primary routing protocol (OSPFv3 AD = 110) so it remains inactive until the primary route fails.
3
Validate next-hop addressing syntax in Cisco IOS.
Using global unicast address 2001:db8:200::2 directly is valid, whereas link-local next hops mandatory require an exit interface parameter.
Cisco IOS requires explicit interface designation only when using link-local IPv6 addresses as next hops.

Anahtar Kavram

Floating IPv6 Static Default Route Configuration
Soru 125Soru →

A network administrator needs to configure a floating static route on a Cisco router to act as a backup link for a primary path learned via OSPF (Administrative Distance of 110). Which Administrative Distance value must be assigned to the floating static route to ensure it is used ONLY when the primary OSPF route becomes unavailable?

Cevabı ve açıklamayı göster

Cevap: 120

Cevap

The floating static route must be configured with an Administrative Distance greater than 110 (such as 120).
For a static route to function as a floating static route (backup), its Administrative Distance must be configured to a value higher than that of the primary route protocol. Since OSPF has an AD of 110, an AD of 120 ensures the static route remains out of the routing table until the OSPF route fails.

Adım Adım Çözüm

1
Identify the Administrative Distance (AD) of the primary dynamic route.
The primary route is learned via OSPF, which has a default AD of 110.
Routers prefer routes with lower AD values when installing paths into the routing table.
2
Determine the AD requirement for a backup (floating) static route.
The floating static route must have an AD higher than 110 (for example, 120).
Assigning a higher AD keeps the backup route inactive ('floating') until the lower AD primary route disappears from the routing table.

Anahtar Kavram

Floating Static Route Administrative Distance Selection
Tahmini Süre:45s
Soru 126Soru →

Two directly connected Cisco routers are configured with OSPFv2 on their connecting interfaces. Router R1 has its interface assigned to OSPF Area 0, while Router R2 has its connecting interface assigned to OSPF Area 1. Assuming all other OSPF parameters are left at default settings, what is the result of this configuration?

Cevabı ve açıklamayı göster

Cevap: The routers fail to form an OSPF neighbor adjacency because the Area IDs do not match.

Cevap

The routers fail to form an OSPF neighbor adjacency because the Area IDs do not match.
For two OSPFv2 routers to establish a neighbor adjacency, several interface parameters exchanged in Hello packets must match exactly. One mandatory parameter is the Area ID. Because one router's interface is configured in Area 0 and the other in Area 1, the routers reject each other's Hello packets and fail to form an adjacency.

Adım Adım Çözüm

1
Identify the mandatory matching parameters required in OSPF Hello packets for neighbor formation.
Area ID, Subnet Mask, Hello/Dead Intervals, Authentication, and Option flags (such as Stub area flags) must match between neighbors on a link.
OSPF routers validate these fields upon receiving a Hello packet before accepting the sending router as a valid neighbor.
2
Evaluate the effect of placing connecting interfaces into different areas (Area 0 vs. Area 1).
Incoming OSPF Hello packets are dropped due to the Area ID mismatch.
Because the Area ID field in the Hello header does not match the local interface's configured area, neighbor discovery fails immediately.

Anahtar Kavram

OSPFv2 Neighbor Adjacency Requirements
Soru 127Soru →

An engineer needs to configure a static route on a Cisco router to forward traffic destined for 2001:db8:a:10::/642001:\text{db8}:\text{a}:10::/64. The route must use the next-hop router's link-local address fe80::211:25ff:feab:1234\text{fe80}::211:25\text{ff}:\text{feab}:1234 via the local interface GigabitEthernet0/1. Which command correctly configures this IPv6 static route?

Cevabı ve açıklamayı göster

Cevap: ipv6 route 2001:db8:a:10::/64 GigabitEthernet0/1 fe80::211:25ff:feab:1234

Cevap

ipv6 route 2001:db8:a:10::/64 GigabitEthernet0/1 fe80::211:25ff:feab:1234
The command 'ipv6 route 2001:db8:a:10::/64 GigabitEthernet0/1 fe80::211:25ff:feab:1234' is correct because configuring an IPv6 static route with a link-local next-hop address requires a fully specified route configuration that explicitly specifies the local exit interface prior to the link-local next-hop address.

Adım Adım Çözüm

1
Identify the proper command syntax for IPv6 static routing.
The configuration must use the global configuration command starting with 'ipv6 route' followed by the target destination prefix and prefix length (2001:db8:a:10::/64).
Cisco IOS differentiates IPv4 and IPv6 static routes by requiring the 'ipv6 route' keyword for IPv6.
2
Determine the required parameters for a link-local next-hop address.
Because the next-hop is a link-local address (fe80::/10), the command must explicitly include both the exit interface (GigabitEthernet0/1) and the link-local address (fe80::211:25ff:feab:1234).
Link-local addresses are only valid on a specific physical link. Without the local exit interface context, the router cannot determine which outgoing interface to use to reach the next-hop.

Anahtar Kavram

Fully Specified IPv6 Static Route
Tahmini Süre:1m 0s
Soru 128Soru →

Match each Layer 2 discovery protocol attribute or configuration parameter on the left to its corresponding protocol or timer specification on the right.

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Öğeler

Cisco proprietary protocol enabled globally by default on Cisco switch platforms
Vendor-neutral discovery protocol standardized under IEEE 802.1AB
Protocol default update frequency of 60 seconds with a holdtime of 180 seconds
Protocol default update frequency of 30 seconds with a holdtime of 120 seconds

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

The Cisco proprietary protocol matches Cisco Discovery Protocol (CDP). The IEEE 802.1AB standard matches Link Layer Discovery Protocol (LLDP). The 60-second update and 180-second holdtime match CDP Default Timers. The 30-second update and 120-second holdtime match LLDP Default Timers.
Each left-side item correctly correlates to its designated discovery protocol origin, governing IEEE specification, or default timer values.

Adım Adım Çözüm

1
Differentiate between proprietary and open standard Layer 2 discovery protocols.
Identify CDP as Cisco proprietary and LLDP as IEEE 802.1AB standard.
CDP operates exclusively on Cisco devices by default, whereas LLDP allows interoperability across heterogeneous vendor environments.
2
Compare default advertisement and holdtime timers for CDP and LLDP.
Map 60s update / 180s holdtime to CDP, and 30s update / 120s holdtime to LLDP.
CDP sends updates less frequently (60s) than LLDP (30s) under default Cisco IOS configurations.

Anahtar Kavram

Layer 2 Discovery Protocols (CDP vs LLDP standards, ownership, and default timers)
Soru 129Soru →

Branch router R2 needs to reach host devices in the remote subnet 172.20.15.0/24172.20.15.0/24. The next-hop router interface connected to R2 is assigned the IPv4 address 10.1.1.210.1.1.2. Which Cisco IOS command correctly defines this IPv4 static route?

Cevabı ve açıklamayı göster

Cevap: ip route 172.20.15.0 255.255.255.0 10.1.1.2

Cevap

The correct command is 'ip route 172.20.15.0 255.255.255.0 10.1.1.2'.
The correct command adheres precisely to Cisco IOS syntax: 'ip route <destination-prefix> <subnet-mask> <next-hop-ip>'. For a /24/24 destination network of 172.20.15.0172.20.15.0 reached via 10.1.1.210.1.1.2, the proper entry is 'ip route 172.20.15.0 255.255.255.0 10.1.1.2'.

Adım Adım Çözüm

1
Identify the target destination prefix and length.
Destination prefix is 172.20.15.0172.20.15.0 with prefix length /24/24.
Static routing requires specifying the destination network ID.
2
Convert prefix length /24/24 to dotted-decimal subnet mask format.
Mask is 255.255.255.0255.255.255.0.
Cisco IOS global configuration syntax requires dotted-decimal subnet masks for IPv4 static routes.
3
Assemble parameters into Cisco IOS command structure 'ip route <destination> <mask> <next-hop>'.
'ip route 172.20.15.0 255.255.255.0 10.1.1.2'
This matches standard Cisco CLI global configuration syntax.

Anahtar Kavram

IPv4 Static Route Syntax
Soru 130Soru →

A network administrator needs to configure a floating static default route on a Cisco IOS router to serve as a backup path to a primary default route learned via OSPF. Which two statements accurately describe the requirements for this configuration? (Select TWO)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: The static route command must specify a destination network of 0.0.0.00.0.0.0 and a subnet mask of 0.0.0.00.0.0.0.; The administrative distance configured for the backup static route must be greater than 110110.

Cevap

To configure a floating static default route as a backup to an OSPF route, the destination address and mask must be configured as 0.0.0.0 0.0.0.0, and the administrative distance must be configured to a value greater than 110.
A static default route requires the destination network 0.0.0.00.0.0.0 and mask 0.0.0.00.0.0.0. To make this static route function as a backup (floating route) to an OSPF-learned route, its administrative distance must be higher than OSPF's default AD of 110110.

Adım Adım Çözüm

1
Identify the destination prefix and mask for a default static route.
A default route matches all traffic using the IPv4 prefix 0.0.0.0 and subnet mask 0.0.0.0.
The default static route syntax requires 'ip route 0.0.0.0 0.0.0.0 {ip-address | exit-interface}'.
2
Determine the required Administrative Distance (AD) for a floating backup route.
Since OSPF has a default AD of 110, the static route AD must be set to 111 or higher.
Cisco routers prefer routes with lower AD values. To ensure the static route is used only when the OSPF route fails, its AD must be higher than the OSPF AD.

Anahtar Kavram

IPv4 Floating Static Default Route Requirements
Soru 131Soru →

A system engineer is configuring a static IPv4 address for a database server located on a segment designated with a network ID of 172.30.100.0172.30.100.0 and a subnet mask of 255.255.254.0255.255.254.0. Company security policy requires that the configured address must be a valid usable host address within the assigned subnet and must also belong to the RFC 1918 private IPv4 address space. Which IPv4 address is a valid host address for this server?

Cevabı ve açıklamayı göster

Cevap: 172.30.101.250172.30.101.250

Cevap

172.30.101.250
The subnet mask 255.255.254.0255.255.254.0 creates subnets with a block size of 22 in the third octet. For the network ID 172.30.100.0172.30.100.0, the subnet encompasses 172.30.100.0172.30.100.0 through 172.30.101.255172.30.101.255, giving a usable host range of 172.30.100.1172.30.100.1 to 172.30.101.254172.30.101.254. The IP address 172.30.101.250172.30.101.250 falls cleanly inside this usable host range and is also a valid RFC 1918 private address (within 172.16.0.0/12172.16.0.0/12).

Adım Adım Çözüm

1
Determine the CIDR prefix and block size for subnet mask 255.255.254.0.
The subnet mask 255.255.254.0 corresponds to a /23 prefix length. The block size in the third octet is calculated as 256 - 254 = 2.
Calculating the block size identifies how the subnets increment across octets.
2
Calculate the network ID, broadcast address, and usable host range for the 172.30.100.0/23 subnet.
The network address is 172.30.100.0, the broadcast address is 172.30.101.255, and the range of valid usable host IPs is 172.30.100.1 through 172.30.101.254.
Host IP addresses cannot use the subnet network ID (first IP) or broadcast address (last IP).
3
Verify compliance with RFC 1918 private IPv4 address boundaries.
RFC 1918 specifies the Class B private IP range as 172.16.0.0 to 172.31.255.255 (172.16.0.0/12 block). The address 172.30.101.250 falls inside this range.
Addresses starting with 172.32.x.x fall outside RFC 1918 limits and are public addresses.

Anahtar Kavram

IPv4 Subnet Mask Calculation and RFC 1918 Private Address Boundaries
Soru 132Soru →

A Layer 2 switch receives an Ethernet frame with a unicast destination MAC address that does not currently exist in its MAC address table. Which two actions does the switch take upon receiving this frame?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: It floods the frame out all active interfaces in the VLAN except the ingress port.; It examines the source MAC address of the frame and updates its MAC address table if the entry is missing.

Cevap

The switch populates its MAC address table using the ingress frame's source MAC address and floods the frame out all active switch ports within the VLAN, excluding the port on which the frame arrived.
When a Layer 2 switch receives a frame, it always inspects the source MAC address to learn or update its location in the MAC address table. If the destination MAC address is unknown, the switch performs an unknown unicast flood by forwarding the frame to all active interfaces in the VLAN, except the port on which the frame was received.

Adım Adım Çözüm

1
Inspect the incoming Ethernet frame header.
The switch identifies the frame's source MAC address and destination MAC address.
Learning and forwarding decisions are based on Layer 2 MAC addresses.
2
Process the source MAC address for learning.
The source MAC address is mapped to the ingress switch port in the MAC address table.
The MAC address table populates dynamically from incoming traffic source addresses.
3
Determine forwarding action based on destination MAC address lookup.
Since the destination MAC address is not found in the table, the frame is classified as unknown unicast and flooded out all ports except the receiving port.
Flooding ensures the frame reaches its intended destination even if its switch port location is currently unknown.

Anahtar Kavram

Switch learning mechanics and unknown unicast flooding
Soru 133Soru →

An administrator is configuring an IEEE 802.1Q trunk link between two Cisco Catalyst switches. By default, how does an IEEE 802.1Q trunk process Ethernet frames that belong to the configured native VLAN across the interswitch link?

Cevabı ve açıklamayı göster

Cevap: It forwards frames belonging to the native VLAN untagged without inserting a 4-byte 802.1Q header.

Cevap

IEEE 802.1Q trunks forward Ethernet frames belonging to the native VLAN untagged without inserting a 4-byte 802.1Q tag header.
Under default IEEE 802.1Q operational mechanics, frames associated with the native VLAN are forwarded across interswitch trunk links in their original Ethernet format without an inserted 4-byte 802.1Q header tag. When the receiving switch accepts an untagged frame on its trunk port, it places that frame into its local native VLAN.

Adım Adım Çözüm

1
Identify the standard frame-handling behavior of IEEE 802.1Q trunking for native VLAN traffic.
IEEE 802.1Q specifies that traffic belonging to the designated native VLAN is transmitted across trunk links without a tag.
Transmitting native VLAN frames untagged allows backward compatibility with legacy switches or end-user devices that do not support VLAN tagging.
2
Compare native VLAN frame processing against tagged VLAN frame processing.
Non-native VLAN frames receive a 4-byte 802.1Q tag header, whereas native VLAN frames remain untagged.
The receiving switch inspects incoming frames on a trunk link; any frame lacking an 802.1Q tag is automatically assigned to the trunk port's configured native VLAN.

Anahtar Kavram

IEEE 802.1Q Native VLAN Untagged Traffic Handling
Soru 134Soru →

An Ethernet frame with a destination MAC address of FFFF.FFFF.FFFF arrives on switch port FastEthernet0/5. The switch MAC address table currently contains no entry for the source MAC address of the frame. Which dual action will the switch perform upon receiving this frame?

Cevabı ve açıklamayı göster

Cevap: Record the source MAC address mapped to FastEthernet0/5 in the MAC table, and flood the frame out all active switch ports except FastEthernet0/5.

Cevap

Record the source MAC address mapped to FastEthernet0/5 in the MAC table, and flood the frame out all active switch ports except FastEthernet0/5.
When a Layer 2 switch receives an Ethernet frame, it first inspects the source MAC address. If the source MAC is not present in the MAC table, the switch creates a new entry mapping that source MAC address to the receiving port (FastEthernet0/5). Next, it inspects the destination MAC address. Because FFFF.FFFF.FFFF is the Layer 2 broadcast address, the switch floods the frame out every active interface in the VLAN except the interface on which the frame arrived.

Adım Adım Çözüm

1
Examine the incoming frame's source MAC address and ingress port.
The switch notes that the source MAC address is not currently in the MAC address table.
Layer 2 switches perform MAC learning by recording the incoming source MAC address associated with the ingress interface (FastEthernet0/5).
2
Examine the incoming frame's destination MAC address.
The destination MAC address is identified as FFFF.FFFF.FFFF (Layer 2 broadcast).
Broadcast frames are intended for all devices within the broadcast domain.
3
Execute frame forwarding.
The frame is flooded out all operational ports belonging to the same VLAN, excluding the receiving port (FastEthernet0/5).
Flooding ensures all hosts receive the broadcast, while excluding the ingress port prevents frame loops.

Anahtar Kavram

Layer 2 MAC Address Table Learning and Broadcast Frame Flooding Logic
Soru 135Soru →

An organization is assigned the IPv6 address block 2001:db8:1111:2000::/522001:\text{db8}:1111:2000::/52. A network engineer needs to configure a router interface within a new /64 subnet that has a 12-bit subnet ID extension of 0xA400x\text{A40} added to the base /52 prefix. The router interface uses EUI-64 to generate its interface identifier automatically based on its MAC address `0200.4C12.3456`. Which IPv6 Global Unicast Address will be dynamically configured on this interface?

Cevabı ve açıklamayı göster

Cevap: 2001:db8:1111:2a40::4cff:fe12:3456

Cevap

2001:db8:1111:2a40::4cff:fe12:3456
The subnet prefix is derived by adding the subnet ID extension 0xA400x\text{A40} to the base prefix 4th hextet (20002000), producing 2A402\text{A}40. For EUI-64 generation from MAC `0200.4C12.3456`, `FFFE` is inserted into the middle (`0200.4CFF.FE12.3456`), and the 7th bit of the first byte (`0x02` = `0000 0010`) is inverted to `0` (`0x00` = `0000 0000`), yielding `0000:4cff:fe12:3456`. Combining these results in `2001:db8:1111:2a40::4cff:fe12:3456`.

Adım Adım Çözüm

1
Calculate the /64 subnet prefix from the assigned /52 block and subnet offset
Subnet prefix is 2001:db8:1111:2a40::/64
The base /52 prefix ends at the 4th hex digit of the 4th hextet (20002000). Adding the 12-bit hex extension 0xA400x\text{A40} yields 2000+A40=2A402000 + \text{A40} = 2\text{A}40 in hexadecimal for the 4th hextet.
2
Split the MAC address 0200.4C12.3456 into two 24-bit halves and insert FFFE
Intermediate identifier is 0200:4CFF:FE12:3456
EUI-64 requires inserting the hex value FFFE into the middle of the 48-bit MAC address.
3
Invert the 7th bit (Universal/Local bit) of the first byte
First byte 0x02 (binary 0000 0010) becomes 0x00 (binary 0000 0000)
In EUI-64 generation, flipping the 7th bit changes a 1 to a 0 (or 0 to 1), transforming 0200:4CFF:FE12:3456 into 0000:4CFF:FE12:3456 (compressed as ::4cff:fe12:3456).
4
Combine the /64 prefix with the EUI-64 interface identifier
2001:db8:1111:2a40::4cff:fe12:3456
Merging 2001:db8:1111:2a40::/64 and 0000:4cff:fe12:3456 gives the final global unicast address.

Anahtar Kavram

IPv6 EUI-64 Interface Identifier Generation and Subnet Prefix Calculation
Soru 136Soru →

A network administrator configures an OSPFv2 interface on a Multiaccess Ethernet network with the command `ip ospf priority 0`. What is the impact of this configuration on the DR/BDR election process on that segment?

Cevabı ve açıklamayı göster

Cevap: The router interface is completely excluded from becoming either a Designated Router (DR) or Backup Designated Router (BDR).

Cevap

The router interface is completely excluded from becoming either a Designated Router (DR) or Backup Designated Router (BDR).
In OSPFv2 multiaccess networks, setting an interface's priority to 0 explicitly revokes its eligibility to participate in DR and BDR elections. The interface remains in the DROTHER state and forms adjacencies only with the elected DR and BDR.

Adım Adım Çözüm

1
Evaluate the function of OSPF interface priority values.
OSPF interface priority ranges from 0 to 255, where default priority is 1.
The priority value determines eligibility and preference during DR/BDR elections on broadcast multiaccess networks.
2
Analyze the specific behavior of priority 0.
Configuring `ip ospf priority 0` marks the interface as ineligible for DR/BDR roles.
A router with priority 0 will always transition directly to the DROTHER state upon adjacency establishment.

Anahtar Kavram

OSPF Interface Priority 0 and DR/BDR Ineligibility
Soru 137Soru →

A network administrator needs to configure an IPv4 static default route on a Cisco router pointing to the next-hop IP address 203.0.113.1. Which Cisco IOS command correctly accomplishes this configuration?

Cevabı ve açıklamayı göster

Cevap: ip route 0.0.0.0 0.0.0.0 203.0.113.1

Cevap

ip route 0.0.0.0 0.0.0.0 203.0.113.1
The correct command uses 'ip route 0.0.0.0 0.0.0.0 203.0.113.1'. In Cisco IOS, a static default route is configured using the prefix 0.0.0.0 and mask 0.0.0.0 followed by either the next-hop IPv4 address or an outbound interface.

Adım Adım Çözüm

1
Identify the standard Cisco IOS syntax for IPv4 static routing.
The standard syntax is 'ip route <destination-prefix> <subnet-mask> {ip-address | exit-interface}'.
Cisco IOS requires explicit declaration of the target network prefix, subnet mask, and forwarding target.
2
Determine the prefix and mask required for a static default route.
A default route matching all IPv4 destinations uses network prefix 0.0.0.0 and subnet mask 0.0.0.0.
The prefix 0.0.0.0/0 matches any IPv4 address when no more specific match exists in the routing table.
3
Append the specified next-hop IP address.
Combining the default prefix/mask with next-hop IP 203.0.113.1 yields 'ip route 0.0.0.0 0.0.0.0 203.0.113.1'.
The next-hop IP address designates the forwarding address of the adjacent router.

Anahtar Kavram

IPv4 Static Default Route Configuration
Soru 138Soru →

An enterprise network is deploying a centralized Cisco Wireless LAN Controller (WLC) solution based on the Split-MAC architecture. Which operational function is performed by the centralized WLC rather than the Lightweight Access Point (LAP)?

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Cevap: Processing 802.11 client authentication requests and translating 802.11 frames to 802.3 Ethernet frames

Cevap

Processing 802.11 client authentication requests and translating 802.11 frames to 802.3 Ethernet frames
Under Cisco's Split-MAC architecture, functions are split based on real-time sensitivity. Non-real-time management and control activities—such as processing client authentication, managing association states, and performing 802.11-to-802.3 frame translation—are handled centrally by the WLC.

Adım Adım Çözüm

1
Analyze the Split-MAC architecture concept.
Recognize that wireless MAC functions are divided into real-time functions (handled by the LAP) and non-real-time functions (handled by the WLC).
Split-MAC optimizes performance by handling time-sensitive 802.11 tasks locally on the AP while centralizing management and higher-layer processing on the WLC.
2
Categorize the responsibilities of the Lightweight Access Point (LAP).
LAPs handle transmission of beacons, probe responses, immediate MAC layer acknowledgments (ACKs), RTS/CTS frame exchanges, and power-save buffering.
These tasks require immediate radio-level responses and cannot tolerate CAPWAP tunnel latency to a remote controller.
3
Categorize the responsibilities of the Wireless LAN Controller (WLC).
The WLC handles non-real-time management, 802.11 authentication/association, 802.1X/EAP processing, Radio Resource Management (RRM), and 802.11 to 802.3 frame translation.
Centralizing these functions allows uniform security policy enforcement and seamless mobility across the network.

Anahtar Kavram

Split-MAC Architecture Functional Division
Tahmini Süre:1m 0s
Soru 139Soru →

An administrator is configuring OSPFv2 on Router R1. The router has no explicit 'router-id' command under its OSPF process, but has the following active interfaces:
- Loopback0: 172.16.1.1/32
- Loopback1: 10.200.1.1/32
- GigabitEthernet0/0: 10.0.0.1/24 (configured with 'ip ospf 1 area 0')

Directly connected on GigabitEthernet0/0 is Router R2, which has its OSPF process configured with an explicit 'router-id 172.16.1.1' and GigabitEthernet0/0 (10.0.0.2/24) in Area 0. When both routers attempt to form an adjacency, R1 shows R2 stuck in the INIT state, and R2 logs report duplicate OSPF packets.

Based on OSPF election logic and neighbor requirements, why is the neighbor relationship stuck in this state?

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Cevap: R1 selected 172.16.1.1 as its Router ID because it has the highest IP address among active loopback interfaces, causing a duplicate Router ID conflict with R2.

Cevap

R1 selected 172.16.1.1 as its Router ID because it has the highest IP address among active loopback interfaces, causing a duplicate Router ID conflict with R2.
The correct answer identifies that R1 automatically selects 172.16.1.1 as its Router ID because 172.16.1.1 is the highest IP address among its active loopback interfaces (172.16.1.1 vs 10.200.1.1). Because R2 has an explicit Router ID of 172.16.1.1, both routers share the same Router ID on the segment. Routers with duplicate Router IDs ignore or reject each other's Hello packets and fail to list each other as valid neighbors, causing the relationship to remain stuck in the INIT state.

Adım Adım Çözüm

1
Determine the OSPF Router ID selection logic on R1.
Since no explicit 'router-id' command is configured, R1 checks active loopback interfaces. It compares Loopback0 (172.16.1.1) and Loopback1 (10.200.1.1). Because 172.16.1.1 is numerically higher than 10.200.1.1, R1 selects 172.16.1.1 as its OSPF Router ID.
OSPF Router ID election order is: 1) Explicit 'router-id' command, 2) Highest IP address among active loopbacks, 3) Highest IP address among active physical interfaces.
2
Compare R1's Router ID with R2's Router ID.
R2 is explicitly configured with OSPF Router ID 172.16.1.1. Both R1 and R2 are using the identical Router ID (172.16.1.1) on the same network segment.
Duplicate OSPF Router IDs on the same segment prevent routers from establishing bi-directional communication.
3
Analyze the impact of duplicate Router IDs on OSPF neighbor state.
When R2 receives Hello packets from R1 with a source Router ID identical to its own, it discards them or fails to list R1 as a valid neighbor. R1 receives Hello packets but never sees its own Router ID listed in R2's Hello packet neighbor field, keeping the state stuck in INIT.
Transitioning from INIT to 2-WAY requires a router to see its own Router ID in the received Hello packet's neighbor list.

Anahtar Kavram

OSPFv2 Router ID Election Hierarchy and Duplicate Router ID Neighbor Behaviors
Soru 140Soru →

Two Cisco routers, R1 and R2, are connected via their GigabitEthernet0/0 interfaces on the 192.168.12.0/24 subnet in OSPF Area 0.

R1 operational status:
- Loopback 0: IP 10.10.10.1/32 (up/up)
- Loopback 1: IP 172.16.1.1/32 (up/down)
- GigabitEthernet0/0: IP 192.168.12.1/24 (up/up, MTU 1500)
- OSPF Process 1 was initialized while only Loopback 0 was active. Later, the command `router-id 1.1.1.1` was added under `router ospf 1`, but `clear ip ospf process` has not been executed.

R2 operational status:
- Loopback 0: IP 10.20.20.1/32 (up/up)
- GigabitEthernet0/0: IP 192.168.12.2/24 (up/up, MTU 1400)
- Hello and Dead timers match R1 on GigabitEthernet0/0.

Which TWO statements accurately describe the OSPF operational state and Router ID behavior between R1 and R2?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: R1 currently uses 10.10.10.1 as its active OSPF Router ID because the `router-id` command requires clearing the OSPF process to take effect.; R1 and R2 will establish a neighbor relationship up to the 2-Way state but will remain stuck in the ExStart/Exchange state.

Cevap

R1 uses 10.10.10.1 as its active OSPF Router ID because the manual `router-id` configuration requires resetting the OSPF process, and the routers will successfully achieve 2-Way neighbor state but become stuck in ExStart/Exchange state due to the MTU mismatch on GigabitEthernet0/0.
The statement regarding R1 using 10.10.10.1 is correct because manual `router-id` commands under `router ospf` are non-preemptive and require an explicit process reset (`clear ip ospf process`) to replace an already active router ID. The statement regarding the routers reaching 2-Way state but stalling in ExStart/Exchange is correct because MTU is not checked in Hello packets (allowing 2-Way neighbor discovery), but MTU mismatches fail verification during Database Description (DBD) packet exchanges in ExStart state.

Adım Adım Çözüm

1
Determine active OSPF Router ID for R1.
R1 selected 10.10.10.1 (Loopback 0) during process initialization. Adding `router-id 1.1.1.1` later is non-preemptive and does not take effect until `clear ip ospf process` is executed. Loopback 1 (172.16.1.1) is down and ignored.
OSPF Router ID election logic evaluates active (up/up) interfaces at process startup, and manual CLI configuration changes are non-preemptive.
2
Evaluate Hello packet negotiation parameters between R1 and R2.
Hello and Dead timers match, Area IDs match (Area 0), subnet masks match, and authentication matches. Both routers receive each other's Hello packets and transition through INIT to 2-Way state.
MTU parameters are not included in OSPF Hello packets and do not prevent 2-Way neighbor state formation.
3
Evaluate Database Description (DBD) exchange between R1 and R2.
During ExStart/Exchange state, routers exchange DBD packets containing interface MTU values. Because R1 (MTU 1500) and R2 (MTU 1400) mismatch, neither router accepts the slave/master DBD renegotiation, trapping adjacency progression in ExStart/Exchange.
Cisco IOS enforces strict MTU matching in DBD packets during OSPF ExStart/Exchange states.

Anahtar Kavram

OSPF Router ID Non-Preemptive Election and MTU Mismatch Adjacency Impact
Tahmini Süre:3m 0s
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