Cisco 300-425 Designing Cisco Enterprise Wireless Networks (ENWLSD) Exam Practice Test

 In an outdoor mesh network designed to cover sports fields, a 5 GHz, 14-dBi patch antenna is suitable for the RAP for backhaul connectivity. The higher gain and directional nature of a patch antenna help in focusing the signal over longer distances and in specific directions, which is ideal for connecting various points in a large outdoor area5.

https://www.cisco.com/c/en/us/products/collateral/wireless/aironet-antennas-accessories/product_data_sheet09186a008008883b.html

 Changing the TPC Power Threshold to -65 dBm would generally result in a decrease in the transmit power of APs to maintain a smaller cell size. This helps in reducing interference and improving overall network performance. A lower threshold means the APs reduce their power to ensure the signal does not exceed -65 dBm, leading to decreased signal strength at the client side.

In Cisco WLC version 8, the need for separate WPlus licenses has been eliminated as all features that were previously part of the WPlus license are now included in the Base license. This consolidation simplifies licensing management and ensures that customers have access to all necessary features without requiring additional licenses. References := (CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice)

To focus the coverage heat map on the desired coverage, the engineer should use the RSSI slider to set the heat map to the desired cutoff filter. This action will adjust the display to show only the signal levels that meet or exceed the specified RSSI value, effectively filtering out weaker signals and highlighting areas with sufficient coverage. References: Designing Cisco Enterprise Wireless Networks (ENWLSD 300-425)

In a high-density environment like an auditorium, where APs are in close proximity and a large number of devices are connected, the RF profile is used to adjust the radio frequencies of the APs to minimize co-channel interference. The RF profile allows for the configuration of power levels, channel width, and channel assignment to optimize wireless performance and reduce interference. References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

For outdoor wireless networks, especially in open areas prone to harsh weather, it’s crucial to install lightning arrestors to protect against electrical surges caused by lightning strikes. Additionally, grounding the antenna cables helps dissipate any electrical charge that could damage the equipment.

To support VoWLAN services and provide roaming recommendations to supported voice clients without impacting non-VoWLAN clients, the feature that should be enabled on the VoWLAN SSID is 802.11k neighbor lists. This feature allows APs to provide information about neighboring APs that are candidates for roaming, which helps clients make better decisions about when and where to roam. References := CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

When identifying network requirements, it’s important to consider the number of wireless devices that will need access to ensure sufficient capacity and coverage. The business type can influence the types of applications and services that will be used, which in turn affects the network design.

The voice readiness tool in Cisco Prime inspects the network against a dBm range that is suitable for voice over Wi-Fi. The range of -72 to -67 dBm is considered optimal for voice applications, ensuring clear audio quality and minimal packet loss.

https://www.cisco.com/c/en/us/td/docs/net_mgmt/prime/infrastructure/34/user/guide/bk_CiscoPrimeInfrastructure_3_4_0_UserGuide/bk_CiscoPrimeInfrastructure_3_4_0_UserGuide_chapter_01010.html

 For an active survey where the application requires a minimum RF of -73 dBm, the mobile device used for the survey should have a receiver sensitivity of -70 dBm or better. This ensures that the device is sensitive enough to detect the minimum required signal strength for the application to function properly.

To reduce co-channel interference, it’s beneficial to decrease channel bonding, which will increase the number of non-overlapping channels available. Reducing the power of the APs can also help minimize interference by reducing the range of each AP’s signal, thereby reducing the chance of overlap.

When using the Cisco Prime Infrastructure Planning Tool for deploying a Greenfield 802.11n network with data, voice, location awareness, and APs equipped with WSSI modules, selecting ‘Voice’ will ensure that the tool accounts for the additional bandwidth requirements of voice applications which have strict QoS requirements. Choosing ‘Location’ will allow the tool to consider the need for more precise location tracking capabilities which typically require additional APs for triangulation purposes. References := CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

 Cisco FlexConnect mode is designed for branch offices that lack a wired backhaul. It allows APs to switch client data traffic locally while still performing client authentication centrally. This mode provides the flexibility needed for branch deployments, ensuring that client traffic is handled efficiently even if the WAN link to the central site is down. References: Cisco FlexConnect technical documentation and Designing Cisco Enterprise Wireless Networks (ENWLSD) training.

 The wireless architecture described is a centralized deployment. This is characterized by access points distributed across multiple buildings and managed centrally by Wireless LAN Controllers (WLCs). Centralized deployments are common in larger environments like a technology company campus because they allow for centralized management, scalability, and advanced features such as load balancing and fault tolerance.

For Cisco Wireless LAN Controllers (WLCs) to operate in High Availability (HA) with Stateful Switch Over (SSO), they must be connected through a Redundancy Port (RP). This dedicated port is used for synchronization of stateful information and ensuring seamless failover without service interruption.

 The AP fallback feature is designed to allow access points to return to their primary controller after they have connected to a secondary controller due to a failure or connectivity issue with the primary. This setting ensures that once the primary controller is back online, the APs will recognize it and re-establish their connection as per the original network design. This feature is crucial for maintaining the intended controller hierarchy and ensuring seamless wireless network operation.

AP Fallback is a feature that allows APs to rejoin their primary controller after they have connected to a secondary controller due to a failure. By enabling AP Fallback on the primary controller, the APs will automatically rejoin it when it becomes available again after a power interruption. This ensures that APs return to their designated primary controller for normal operations.

To reduce full authentication requests and optimize roaming, enabling Cisco Centralized Key Management (CCKM) on the voice SSID is effective. CCKM allows for fast re-authentication during roaming, which is beneficial for voice applications. Adding APs to a FlexConnect group helps manage APs in remote branches more efficiently.

To support high availability, the design must include redundant Wireless LAN Controllers (WLCs) to ensure service continuity in case of a failure. Additionally, having a high availability pair with one WLC holding a valid AP count license ensures that all APs can remain connected and services continue without interruption during failover.

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/7-5/High_Availability_DG.html#pgfId-44074

In a high availability setup with Cisco 5508 Wireless LAN Controllers, the standby controller can be accessed via the console connection and the service port interface. The console provides direct access, while the service port interface allows for network-based access to the standby unit for management purposes.

The Cisco 5520 WLC supports Link Aggregation (LAG), which allows multiple physical interfaces to be treated as a single logical channel. By connecting a second 10-GB interface and implementing LAG, the customer can increase the throughput capacity and provide redundancy without the need for a second controller. This approach also simplifies network design and management by reducing the number of IP addresses needed for the controllers and APs. References: Designing Cisco Enterprise Wireless Networks (ENWLSD) training and certification materials.

Quality of Service (QoS) is essential for prioritizing cloud services like email and real-time communication. It helps in managing bandwidth allocation and ensuring that critical applications receive the necessary resources for optimal performance.

https://community.cisco.com/t5/wireless-mobility-documents/what-is-cckm-and-how-does-it-affect-fast-and-secure-roaming/ta-p/3130421

 The redundancy management heartbeat in Cisco Wireless LAN Controllers (WLCs) running 8.x code in Stateful Switch Over (SSO) mode uses UDP packets for communication. When troubleshooting connectivity issues between two WLCs, it is essential to filter for UDP packets in a packet capture to verify the heartbeat communication. The heartbeat packets are sent on a specific UDP port, and filtering for this port can help isolate the heartbeat traffic from other types of traffic in the capture.

By segmenting the VLAN into smaller subnets and assigning them by location, an engineer can use interface groups. This allows for efficient management of network resources and ensures that clients are connected to the closest subnet, reducing latency and improving performance.

 When designing a backhaul link, the mesh AP role should be set to ‘bridge’ to enable it to connect separate network segments or extend coverage to remote areas.

 In an auditorium seating 500 students with laptops, a high-density design model is appropriate. This model focuses on supporting a large number of devices in a concentrated area with sufficient coverage and bandwidth. It involves strategic AP placement, proper channel planning, and capacity planning to ensure all students have reliable wireless access. References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

https://www.cisco.com/c/dam/en_us/solutions/industries/docs/education/cisco_wlan_design_guide.pdf

 Before replacing old APs with IEEE 802.11ac-capable APs, it is crucial to check the software version of the wireless LAN controller. The controller’s firmware must support the newer standards and capabilities of 802.11ac APs. An outdated software version may not support the advanced features and performance enhancements offered by 802.11ac technology, leading to compatibility issues and suboptimal network performance.

 The concern with existing gigabit uplinked switches providing 802.3at is the output power limitation. 802.11ac Wave 2 APs may require more power than what 802.3at can deliver, especially for features like Multi-User Multiple Input Multiple Output (MU-MIMO). References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide.

When conducting site surveys for WLAN upgrades to 802.11n, it’s important to consider AP locations that allow for easy access. This facilitates quick maintenance and upgrades, ensuring minimal downtime and disruption to the network. While aesthetics and power availability are also considerations, the primary focus should be on maintaining the network’s performance and reliability.

 Large cases of liquid materials can cause higher signal loss compared to dry goods due to the way radio frequency (RF) waves interact with liquid, which can absorb and reflect the signals more than dry materials.

 RXSOP (Receive Start of Packet Detection Threshold) and TPC (Transmit Power Control) are two features that can help manage the challenges associated with a high AP (Access Point) count in a dense environment like a university auditorium. RXSOP can be adjusted to refine how APs differentiate between noise and valid packets, which is particularly useful in high-density areas where multiple APs might otherwise respond to the same signal. TPC helps in managing the transmit power of APs, allowing for better coverage and reduced interference among APs that are in close proximity to each other. References: Designing Cisco Enterprise Wireless Networks (ENWLSD 300-425)

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/80211/200069-Overview-on-802-11h-Transmit-Power-Cont.html

For accurate location services, it is recommended that each location-ready AP hears at least four other APs at a signal level of -75 dBm or better. This ensures sufficient signal overlap and triangulation accuracy for reliable client location tracking. References: Cisco’s guidelines on wireless network design for location services.

 For Stateful Switchover (SSO) to function correctly, the redundancy ports on both the primary and secondary controllers must be directly connected. This allows for the necessary state and configuration information to be synchronized between the two controllers, preventing the secondary controller from entering maintenance mode in the event of a failover.

 The issue described is indicative of a hidden node problem, where MAP-1 and MAP-3 cannot hear each other’s transmissions but can both communicate with RAP-2. This leads to frame collisions as both MAPs may attempt to transmit at the same time, unaware of the other’s actions. The design needs to address this by implementing mechanisms such as RTS/CTS or adjusting the placement of the APs to avoid this issue.

https://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob30dg/WiMesh.pdf

To minimize channel utilization and interference with existing tenant networks, it’s best to use the UNII-1 channels, which are typically less congested, and stick to 20-MHz channels to provide more non-overlapping channels and reduce co-channel interference.

The WPlus license is suitable for environments using OfficeExtend Access Points (OEAP), which allows employees to work from home with a seamless connection to the corporate wireless network. The WPlus license enables features such as advanced security and increased scalability for remote workers. References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide.

FlexConnect APs must be in a FlexConnect group to support 802.11r Fast Transition (FT). This grouping allows for local authentication and key management, which are necessary for fast roaming methods that improve voice quality and wireless IP phone performance during roaming.

In a Cisco wireless network, when designing for client roaming between access points (APs) that are connected to different controllers, especially in a global enterprise with multiple data centers, it is essential to ensure seamless client mobility. Mobility lists are used in such scenarios to define which controllers are allowed to participate in client roaming. This feature allows the APs connected to controllers within one group (e.g., Group ABC) to recognize and facilitate roaming clients from another group (e.g., Group XYZ). The mobility list is configured on each controller and includes the IP addresses of other controllers that should be considered part of the same mobility domain. When a client roams from an AP on one controller to an AP on another controller, if both controllers are in each other’s mobility list, they will establish a mobility tunnel through which they exchange the client’s context and security credentials. This ensures that the client can roam without re-authentication and maintains session continuity.

To connect multiple wired devices over a workgroup bridge using an autonomous AP, a router is needed to manage the IP addresses and route traffic between the wired devices and the wireless network. The router will act as a gateway for the wired devices, allowing them to communicate with the WLAN. References: Cisco autonomous AP configuration guides and workgroup bridge deployment scenarios.

In a warehouse setting, the height at which access points are installed can significantly impact the wireless signal. If the access points are placed too high, the signal may not adequately reach the users. Additionally, absorption by materials commonly found in warehouses, such as metal racks and goods, can weaken the wireless signal, negatively affecting the users.

https://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1250-series/design_guide_c07-693245.html#_Toc309331086

Access points can be assigned different failover priorities to determine the order in which they will failover in the event of a primary controller failure. An access point with priority 1 is given the highest priority level and is considered critical. This means it will failover before other access points with lower priorities, ensuring that the most critical areas remain covered.

Mobility domains and mobility groups are concepts used in wireless networking to manage client roaming and security contexts. When Wireless LAN Controllers (WLCs) are in the same mobility domain, they can communicate with each other, allowing clients to roam seamlessly between APs managed by different controllers. Mobility groups further refine this by constraining the distribution of a client’s security context, which includes authentication and encryption keys, and by managing AP failover between controllers. This ensures that a client can maintain a secure and stable connection as they move throughout the network.

 For a WLAN design that supports services like internet, email, voice, and database access, a signal strength of -67 dBm is considered good for voice and streaming services. A 25-dB SNR (Signal-to-Noise Ratio) is also desirable for high-quality voice and video applications, and a maximum of 1 percent packet loss is acceptable to ensure reliable connectivity and service quality.

https://www.cisco.com/c/en/us/support/docs/wireless/5500-series-wireless-controllers/116057site-survey-guidelines-wlan-00.html

The behavior of guest client sessions in the US being anchored to the WLCs in Europe despite the presence of a local anchor WLC can be explained by the failure and subsequent recovery of the US anchor WLC. During the failure, the guest sessions would have been transferred to the European WLCs. After recovery, if the priority settings were not correctly restored or if the system did not automatically revert back to the local anchor, the sessions would remain anchored to the European WLCs3.

The Catalyst 9300X-48HX switches support PoE, which can power the 9166 APs. To ensure that all APs run with full functionalities, including PoE, the engineer should connect the APs to all available ports on the stack of two Catalyst 9300X-48HX switches. This will provide sufficient power and connectivity for the APs to operate effectively. References: Cisco Catalyst 9300X switch specifications and PoE requirements for 9166 APs.

An RSSI value of -77 dBm is within the range that a 5 GHz radio can receive and decode, provided it’s not below the RX-SOP threshold set for the RF profile. Since the RF profile is set to Medium for 802.11a, which operates in the 5 GHz band, the AP’s 5 GHz radio will decode the frames.

 Cisco Hyperlocation requires a dense deployment of access points for accurate location tracking. Adding more APs than a standard site survey suggests can meet the granular location requirements needed for Hyperlocation services. References: ENWLSD official certification guide.

The ‘eping’ command is used on Cisco Wireless LAN Controllers to verify that the redundancy peer in a Stateful Switchover (SSO) pair of controllers is up and connected. This command sends ECHO packets to the peer controller to ensure connectivity.

 When a Wireless LAN Controller (WLC) SSO is set up between two WLCs in a service provider network, and there is a failover, the secondary WLC should ideally support the same client count as the primary. If only about half of the original client count is showing on the secondary WLC post-failover, it suggests that the WLCs had not completed the database synchronization before the primary WLC failed. This incomplete sync would result in a loss of client information, leading to a reduced client count on the secondary WLC.

 For a government agency requiring high security between device communications, enabling Mobility Encryption across the network is essential. Mobility Encryption enhances the security of the mobility group by encrypting the traffic exchanged between mobility peers, including AireOS, Cisco IOS-XE controllers, and Cisco 4800 Series APs. This encryption helps to protect against potential eavesdropping and unauthorized access, ensuring that sensitive government data remains confidential during wireless transmission.

When performing a Layer 1 survey using Metageek Chanalyzer, the Cisco CleanAIR AP should be configured in Monitor mode. This mode allows the AP to scan the environment for interference without serving clients.

Aggregated Probe Response Optimization should be enabled on the controller to optimize roaming, especially for environments with a high density of Apple OS devices. This feature reduces airtime consumption and overhead by aggregating probe responses, which can improve the roaming experience for the employees.

The data path being down while the control path is up indicates an issue with the data plane security configuration. The data-dtls setting on the AireOS 5520 WLC is responsible for enabling Datagram Transport Layer Security (DTLS) for the data plane, which encrypts the data traffic between the controllers. If this setting is disabled, the data path cannot be established securely, leading to the observed issue. Therefore, enabling data-dtls on the AireOS 5520 WLC is necessary to resolve the data path downtime.

For handheld mobile scanners processing credit card payments, security and seamless roaming are critical. The 802.11w standard, also known as Protected Management Frames (PMF), provides enhanced security that helps prevent disconnections and issues when roaming between access points. Incorporating 802.11w in the design ensures that the scanners maintain a secure and consistent connection while moving throughout the environment. References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

To optimize roaming in a wireless network with multiple controllers, it is essential to use the same WLAN name (SSID) across all controllers. This allows clients to roam seamlessly between access points managed by different controllers without having to re-authenticate or experience disconnections1.

 The Cisco 5520 WLC v8.3 requires a base license to use OfficeExtend AP functionality, which allows remote workers to have the same wireless connectivity as they would in an office environment.

The issue where APs failed over to the tertiary controller instead of the secondary controller during a controller failure is likely due to the secondary controller being at capacity. When a controller reaches its maximum capacity, it cannot accept any additional APs, causing them to failover to the next available controller in the high availability configuration.

The Cisco AIR-2702i AP can be set to various modes for different purposes. For conducting a Layer 1 site survey to discover non-Wi-Fi interference, the AP should be set to Monitor mode. In this mode, the AP can scan the radio environment for interference sources without serving any clients, making it ideal for use with tools like Metageek Chanalyzer.