Cisco Certified Network Associate (CCNA) 200-301 Practice Test 13
Question 120
Several access points advertise the exact same SSID `CorpNet`; a client moves from radio A to radio B. Which identifier should its association log use to distinguish the particular AP/radio BSS before and after the move?
- Treat the SSID string as a unique hardware identifier for one access point only.
- Use the client's IPv4 default-gateway address as the AP BSSID.
- Assume the radio channel number alone uniquely identifies the associated BSSID.
- Record the BSSID for each association, such as each AP radio's advertised MAC-like BSS identifier, while the SSID can remain `CorpNet`.
Explanation
Correct Answer
D:An SSID is the logical WLAN network name visible to the user. The BSSID identifies a specific basic service set/radio advertisement, so a roaming client may keep the same SSID while its associated BSSID changes.
Incorrect Answers
A:The same SSID can be advertised by multiple APs for one WLAN; it cannot uniquely identify the associated radio.
B:A routed gateway IP is not the 802.11 BSSID broadcast by the AP for association.
C:Multiple APs may operate on the same channel; association identification uses the BSSID, not just channel.
Question 121
A WLAN administrator must enforce a secure preshared-key authentication profile for clients while RF channel selection is handled separately. Which setting directly addresses the authentication requirement?
- Select channel 11 without defining any authentication or encryption policy.
- Assign a different BSSID display name instead of selecting a WLAN authentication mode.
- Configure only an IP static route on the WLC and assume the four-way handshake uses that route.
- Configure a supported WPA2-Personal AES/CCMP or WPA3-Personal SAE security policy with the intended credentials.
Explanation
Correct Answer
D:WPA2/WPA3 security settings determine how stations authenticate and protect frames. Channel, SNR and AP placement govern RF performance; a correct channel plan cannot compensate for a wrong PSK or unsupported authentication mode.
Incorrect Answers
A:Channel selection affects radio interference, not the WLAN key exchange or access policy.
B:BSSID identifies a BSS; it is not a substitute for WPA2/WPA3 security settings.
C:WPA2 handshake/SAE authentication occurs within WLAN security, not because an unrelated Layer 3 static route exists.
Question 122
Three nearby 2.4-GHz access points in a country permitting channels 1 through 11 all use 20-MHz operation. Their radio channels are 1, 2 and 3. Clients show high retransmission rates even with strong signal. Which channel plan most directly reduces adjacent-channel overlap?
- Assign the three APs channels 1, 6 and 11 after checking the local RF survey and country regulations.
- Assign channels 1, 2 and 3 again, increasing transmit power on every radio.
- Put all three radios on channel 6 and disable carrier sensing on their clients.
- Use 40-MHz channels 1, 3 and 5 to create more nonoverlapping 2.4-GHz capacity.
Explanation
Correct Answer
A:In the common 2.4-GHz 20-MHz plan for channels 1–11, channels 1, 6 and 11 are spaced to minimize adjacent-channel overlap. Channels 1, 2 and 3 occupy substantially overlapping spectrum, producing collisions and retransmissions even with strong received signal. An RF survey should also account for co-channel interference and neighboring networks; this arrangement is a starting plan rather than a guarantee of zero interference. Lowering excess transmit power and designing AP placement may additionally improve contention. Channel availability and permitted output power remain subject to the regulatory domain.
Incorrect Answers
B:Increasing transmit power cannot separate channels 1, 2 and 3 in frequency. It can extend their overlapping interference footprints and make contention worse, even though clients report stronger signal. The failure involves spectrum overlap, not simply insufficient signal level. Reassign appropriately spaced channels before escalating power.
C:Using the same channel on every AP creates co-channel contention among those cells; some networks accept planned reuse with appropriate cell boundaries, but it does not provide three independent nonoverlapping channels. Wi-Fi stations rely on carrier sensing and contention rules rather than a switch that disables them to avoid collisions. This proposed change is not a responsible channel-separation fix.
D:Doubling 2.4-GHz channel width to 40 MHz consumes more of the already narrow band and generally increases overlap with nearby WLANs. Channels 1, 3 and 5 are not three separate 40-MHz nonoverlapping allocations. The required plan uses supported 20-MHz operation and sufficient frequency separation after surveying local usage.
Question 123
A client roams between two corporate APs. Logs show SSID `CorpNet` unchanged but associated BSSID changes from `00:11:22:33:44:55` to `00:11:22:33:66:77`. What is the correct interpretation?
- The client changed to a different SSID because any BSSID change implies a new network name.
- The change proves the 2.4 GHz channels overlapped and caused packet corruption.
- The station moved its association to a different BSS/AP while staying on the same logical SSID.
- The AP changed the IPv4 default gateway address and the BSSID is a route-table entry.
Explanation
Correct Answer
C:The SSID identifies the network name, while the BSSID identifies a specific AP radio/BSS. A BSSID transition with stable SSID is the expected association change during a WLAN roam; whether the roam was seamless requires separate latency and authentication analysis.
Incorrect Answers
A:Several APs may broadcast a common SSID but use distinct BSSIDs for client attachment.
B:BSSID transition alone does not establish RF collision or channel overlap.
D:A BSSID is an 802.11 identifier, not a Layer 3 gateway or route-table field.
Question 124
A WLAN client sees the intended SSID at strong RSSI but consistently fails the WPA2-Personal four-way handshake after a password change. Other clients using the new password associate successfully. What failure best explains the affected client?
- The client has the wrong pre-shared passphrase/derived key; correct its stored credential rather than moving the AP to a different RF channel.
- Every client must have no Wi-Fi radio signal because the handshake failed.
- The AP BSSID is necessarily changing because one passphrase was mistyped.
- An overlapping neighboring channel guarantees that the WPA2 PSK cryptographic check will accept a wrong password.
Explanation
Correct Answer
A:In WPA2-Personal, the client and AP derive key material from the agreed passphrase and WLAN identifier and prove possession during the four-way handshake. Strong signal and successful associations by other clients point to a client key mismatch, not general RF outage.
Incorrect Answers
B:The client detects the SSID with strong RSSI and other users authenticate, contradicting broad radio outage.
C:BSSID identifies the associated BSS; mistyped credentials do not themselves change the AP radio identifier.
D:Interference can lose frames but cannot make an incorrect key pass the WPA2 handshake cryptographic verification.
Question 125
AP A and nearby AP B previously used 20-MHz channels 1 and 2, producing adjacent-channel overlap. After moving B to a separated permitted channel, which test best validates improved RF channel conditions?
- Check only that both APs broadcast an SSID, without inspecting channel overlap.
- Verify the client can complete the WPA2 handshake, without evaluating RF channel use.
- Confirm that the two APs have different BSSIDs, while both continue using channels 1 and 2.
- A spectrum/channel-utilization survey shows reduced adjacent-channel energy overlap in the affected area, with a corresponding improvement in airtime/throughput.
Explanation
Correct Answer
D:Channel numbers alone are a configuration assertion; a post-change spectrum or channel-use scan plus real performance data measures whether interference was mitigated. The 2.4 GHz band can still have non-Wi-Fi interferers or co-channel contention.
Incorrect Answers
A:Beacon visibility does not show whether adjacent channel RF energy overlaps or throughput improved.
B:Authentication proves a security exchange, not that the adjacent-channel interference was resolved.
C:Distinct radio identities are expected and do not remove adjacent 20-MHz spectrum overlap.
Question 126
During a controlled WLAN roam within SSID `CorpNet`, what client-side evidence proves which AP/BSS is being used before and after the transition?
- Observe only the SSID `CorpNet` before and after, without recording a BSSID.
- Inspect only the switch IP default route and infer the radio hardware identity.
- Inspect association logs or WLAN client status showing the unchanged SSID and a change to the expected new BSSID.
- Check the DNS resolver name on the laptop and assume it equals the associated AP MAC.
Explanation
Correct Answer
C:The BSSID identifies the AP BSS at the 802.11 association level. Seeing the old and new BSSIDs with the same SSID confirms a radio association change; the client IP address may remain stable under the WLAN mobility design.
Incorrect Answers
A:The SSID is intentionally reused across APs and cannot reveal which radio handled either association.
B:A Layer 3 route does not identify the client's current 802.11 BSS.
D:DNS settings do not encode the AP's BSSID.
Question 127
One WLAN client previously failed the WPA2-Personal key handshake because its stored PSK was outdated, despite strong signal. Following the credential correction, what proof most directly confirms authentication succeeded?
- Client/AP logs show successful WPA2 four-way handshake and authorized association using the expected security profile, followed by permitted data traffic.
- The SSID is visible at high RSSI, but the four-way handshake still fails.
- The AP operates on channel 6 but the client remains rejected with a MIC/key failure.
- The client changes BSSID to a different AP and is still unable to authenticate.
Explanation
Correct Answer
A:A corrected WPA2 PSK permits the peers to establish matching key material and complete their four-way exchange. A successful authorized association and data frame exchange distinguish this from merely detecting a strong RF beacon.
Incorrect Answers
B:Strong RF alone does not validate the cryptographic preshared key.
C:Changing the RF channel does not repair a wrong WPA2 passphrase or key-derivation failure.
D:Roaming among APs sharing the same key policy will not prove a wrong credential was corrected.
Question 128
An application requires a guest operating system with a kernel independently versioned from the physical host. What virtualization design provides that separation?
- Run the application inside a virtual machine managed by a hypervisor, installing the required guest OS and kernel in the VM.
- Place it in an ordinary process container and assume it automatically boots a distinct guest kernel.
- Create a second IPv4 subnet on the host, without changing the application execution environment.
- Configure an LACP bundle on the switch uplink instead of choosing a virtualization type.
Explanation
Correct Answer
A:A VM virtualizes a hardware environment in which a guest operating system boots its own kernel. Ordinary containers share the host kernel and generally cannot use a fundamentally different guest kernel.
Incorrect Answers
B:Containers use OS-level isolation and share the host kernel rather than virtualizing a complete independent guest OS.
C:Layer 3 segmentation cannot supply an independently booted OS kernel.
D:EtherChannel bandwidth/availability does not determine the application's guest kernel independence.
Question 129
A router serves tenants BLUE and RED that both use `10.10.0.0/24`, but their interfaces and routes must remain isolated. Which networking mechanism permits identical prefixes in separate routing tables?
- Install both identical 10.10.0.0/24 networks in the one global RIB with no interface separation.
- Configure only distinct VLAN names while all Layer 3 interfaces continue sharing one global routing context.
- Define VRF BLUE and VRF RED, assign each tenant interface to its VRF, and maintain independent per-VRF routes.
- Change both tenants to the same new 10.11.0.0/24 while retaining one forwarding table.
Explanation
Correct Answer
C:Virtual Routing and Forwarding provides separate Layer 3 RIB/FIB contexts, allowing overlapping prefixes among tenants without treating their routes as one global table. Interface VRF membership and return-path routing must align.
Incorrect Answers
A:The same prefix in a shared global table cannot provide independent tenant forwarding by itself.
B:VLANs separate Layer 2 domains, but do not automatically isolate overlapping routed prefixes unless combined with distinct routing contexts.
D:Renumbering both identically does not provide isolated overlapping route tables.
Question 130
A Linux container image requires a kernel feature absent from the running host. Filesystem mounts and container networking work, but the application fails immediately when invoking that kernel facility. Which diagnosis is best?
- A Linux container always boots its own guest kernel, so the host kernel version cannot matter.
- A VRF route table is missing, which by itself would remove an operating system kernel feature.
- The container shares the host kernel and cannot supply the missing kernel capability without a compatible host or a VM with its own guest kernel.
- A DHCP lease is the only prerequisite for loading kernel modules inside an unprivileged container.
Explanation
Correct Answer
C:Standard OS containers isolate processes but use the host kernel. A container image can bundle user-space libraries, not an independent kernel; incompatible kernel APIs remain unavailable despite working mounts and bridges.
Incorrect Answers
A:Ordinary containers do not boot independent kernels; that is a distinguishing property of virtual machines.
B:VRFs isolate IP routing; they do not provide absent system calls or kernel modules.
D:IP addressing and kernel feature availability are distinct. A lease will not create a missing kernel API.
