350-401 Mock Exam 72 — 25 Questions

Question 1

Drag and drop the steps of MPLS L3VPN packet forwarding steps into the correct order, from first to last.

Accepted Answer

Ingress PE receives IP packet from CE. The order begins with the ingress PE receiving an IP packet from the CE, looking up the VRF to find the next hop and label, pushing the MPLS label stack, forwarding the labeled packet across the MPLS core, and finally the egress PE popping the label and forwarding the IP packet to the destination CE.

Question 2

Drag and drop the steps of AAA accounting for command logging setup into the correct order, from first to last.

Accepted Answer

Enable AAA globally with 'aaa new-model'. To log commands via AAA accounting, you first enable AAA globally, then configure the accounting method list for exec or commands, apply it to the desired lines, and finally verify that commands are being sent to the accounting server.

Question 3

Drag and drop the steps of YANG module import and augmentation resolution into the correct order, from first to last.

Accepted Answer

Import base YANG module. The correct order begins with importing the base YANG module, then importing the augmentation module, resolving dependencies, applying augmentations to the base schema tree, and finally validating the combined schema.

Question 4

A network engineer is planning to deploy model-driven telemetry in a brownfield network with a mix of Cisco IOS-XE and Nexus devices. The engineer wants to use a single collector that supports both gRPC and UDP-based telemetry. The engineer is concerned about the scalability of the solution, as the network has over 5000 devices. Which design consideration is most important to ensure the telemetry solution scales effectively?

Accepted Answer

Deploy a hierarchical collector architecture with load balancers to distribute telemetry streams across multiple collectors. To use a hierarchical collector architecture with load balancers to distribute the telemetry streams. With 5000 devices, a single collector can become overwhelmed, so multiple collectors or a load-balanced cluster is essential. The other options are incorrect because using only periodic subscriptions does not address scalability; using a single YANG model is not practical; and using a single transport protocol is not feasible for a mixed environment.

Answer

Use only periodic subscriptions with long sample intervals to reduce data volume

Answer

Configure all devices to use the same YANG model to simplify the collector configuration

Answer

Use a single transport protocol (gRPC) for all devices to reduce complexity

Question 5

Drag and drop each cisco.ios module on the left to its matching purpose on the right.

Accepted Answer

ios_config: Push configuration commands to Cisco IOS devices. ios_config pushes configuration commands, ios_command runs show commands, ios_facts gathers device facts, ios_vlans manages VLANs, and ios_l3_interfaces configures Layer 3 interfaces.

Question 6

Drag and drop the steps of NAT overload (PAT) packet translation process into the correct order, from first to last.

Accepted Answer

Host sends packet with private source IP and port. The PAT process begins with a host sending a packet with a private source IP and port. The router creates a NAT entry mapping the private address and port to the outside global address and a unique port. It then translates the source IP and port in the packet. When the reply arrives, the router looks up the NAT table to find the original mapping. Finally, it translates the destination back to the private IP and port and forwards the packet to the host.

Question 7

Which two statements about virtual machine migration (vMotion/VMware) or live migration (Hyper-V) are true? (Choose two.)

Accepted Answer

Live migration copies the memory state of the VM from the source host to the destination host while the VM continues to run.. Live migration moves a running VM between hosts with minimal downtime. Option B is correct because live migration typically copies memory pages iteratively while the VM runs. Option D is correct because both the source and destination hosts must have compatible CPU features (e.g., same CPU family or Enhanced vMotion Compatibility). Option A is incorrect because the VM must remain powered on during live migration. Option C is incorrect because shared storage is often used but not mandatory; storage vMotion can migrate without shared storage. Option E is incorrect because the VM retains its IP address and network state after migration.

Answer

During live migration, the virtual machine must be powered off to transfer memory contents.

Answer

Live migration requires that both source and destination hosts use the same shared storage for the VM's virtual disks.

Answer

After a live migration, the virtual machine's IP address changes to match the new network segment.

Question 8

Which three statements about encoding formats in model-driven telemetry are true? (Choose three.)

Accepted Answer

Google Protocol Buffers (GPB) provide a compact, binary encoding that reduces bandwidth usage.. GPB is compact and efficient, often used with gRPC. JSON is human-readable and widely supported. XML is verbose but used in NETCONF. YANG does not define encoding; it defines data models. CBOR is not commonly used in Cisco telemetry.

Answer

YANG defines the encoding format for telemetry data.

Answer

CBOR is a binary encoding format used exclusively in Cisco IOS-XE telemetry.

Question 9

A network engineer runs the following command on Router R5:

R5# show ip ospf border-routers

OSPF Process 1 internal Routing Table

Codes: i - Intra-area route, I - Inter-area route

i 1.1.1.1 [110/10] via 192.168.1.1, GigabitEthernet0/0, ABR, Area 0, SPF 5
i 2.2.2.2 [110/20] via 192.168.1.2, GigabitEthernet0/0, ASBR, Area 0, SPF 5

Based on this output, what can be concluded?

Accepted Answer

Router 1.1.1.1 connects area 0 to another OSPF area.. The output shows an entry for 1.1.1.1 with the label 'ABR' (Area Border Router) and a route type of 'i' (intra-area). An ABR connects two or more OSPF areas, so Router 1.1.1.1 must be connecting Area 0 to another OSPF area. The metric [110/10] and next-hop 192.168.1.1 confirm it is reachable within Area 0.

Answer

Router 2.2.2.2 is an Area Border Router.

Answer

Router 1.1.1.1 is redistributing external routes into OSPF.

Answer

The route to 2.2.2.2 is an inter-area route.

Question 10

Which three statements about STP convergence and timers are true? (Choose three.)

Accepted Answer

The default Max Age timer in classic STP is 20 seconds.. Classic STP convergence relies on timers: Hello (2 sec), Max Age (20 sec), Forward Delay (15 sec). Max Age defines how long a switch waits without receiving a BPDU before re-evaluating the root. Forward Delay is the time spent in listening and learning states (each 15 sec). The total convergence time can be up to 50 seconds (20 sec Max Age + 15 sec listening + 15 sec learning). RSTP improves convergence by using handshakes instead of timers. UplinkFast is a Cisco proprietary feature that reduces convergence time after a root port failure, not a standard STP timer.

Answer

The Hello timer in STP is used to determine how often a switch sends BPDUs, with a default value of 5 seconds.

Answer

UplinkFast is a standard IEEE 802.1D feature that reduces convergence time after a root port failure.

Question 11

Drag and drop the steps of IGMPv3 membership report processing into the correct order, from first to last.

Accepted Answer

Host sends IGMPv3 Membership Report with group and sources. IGMPv3 allows hosts to specify source filtering. The host sends a Membership Report with group and source list. The switch/router receives the report and updates its multicast forwarding table. It adds the group and includes the requested sources. It then forwards multicast traffic from those sources to the host's port. The router periodically sends General Queries to maintain membership.

Question 12

An engineer is troubleshooting an EIGRP issue where a router is not learning a specific route from a neighbor. The engineer runs 'show ip eigrp topology all-links' and sees the route in the topology table with a feasible distance of 100 and a reported distance of 120. The neighbor's advertised distance is 80. The router's own computed distance to the network is 150. The route is not in the routing table. What is the most likely cause?

Accepted Answer

The route is not installed because its metric (150) is not the best metric; the router has another route with a lower metric (100).. The route in the topology table has a computed distance of 150 via the neighbor, but the feasible distance (FD) for this destination is 100, which is the best metric from another neighbor. EIGRP installs only the route with the lowest metric (the successor) into the routing table. Since the computed distance of 150 is higher than the FD of 100, this route is not the best and is not installed. Option C correctly identifies that the route is not installed because there is another route with a lower metric.

Answer

The route is a feasible successor, but the successor route is not present.

Answer

The route is not installed because the reported distance (80) from the neighbor is less than the feasible distance (100), but the router's computed distance (150) is higher.

Answer

The route is not installed because EIGRP is configured for stub routing, which prevents learning routes.

Question 13

A network engineer is deploying Cisco DNA Center in a large campus network with 5000+ devices. After initial setup, the engineer notices that the Assurance module is not receiving telemetry data from many access switches. The switches are running IOS-XE 16.12 and are reachable via SNMP. What is the most likely cause of this issue?

Accepted Answer

The switches are not configured with NETCONF/YANG or telemetry streaming.. Cisco DNA Center Assurance relies on telemetry data collected via NETCONF/YANG or gRPC, not just SNMP. If the switches are not configured for telemetry, Assurance will not receive the necessary data. SNMP is used for inventory and basic monitoring, but not for the rich telemetry required by Assurance.

Answer

The DNA Center appliance is not licensed for the Assurance module.

Answer

The switches are not running the correct IOS-XE version for DNA Center compatibility.

Answer

The SNMP community string is incorrect on the switches.

Question 14

Drag and drop each BGP attribute on the left to its matching type on the right.

Accepted Answer

AS_PATH: Well-known mandatory. AS_PATH and NEXT_HOP are well-known mandatory; LOCAL_PREF is well-known discretionary; MED is optional non-transitive; COMMUNITY is optional transitive.

Question 15

Drag and drop the steps of MSDP peering for inter-domain multicast into the correct order, from first to last.

Accepted Answer

RP learns of active source in its domain. MSDP allows RPs in different domains to share information about active sources. When an RP learns of a new source, it sends a Source-Active (SA) message to its MSDP peers. The peer RP then creates an (S,G) state and can join the source if there are interested receivers.

Question 16

Drag and drop the steps of LACP EtherChannel negotiation and bundle formation into the correct order, from first to last.

Accepted Answer

Exchange LACP system priority to elect active side. LACP first exchanges system priority to determine which side is active, then exchanges port priorities to select which ports bundle, next negotiates the operational key, then forms the bundle by synchronizing parameters, and finally the port channel interface becomes operational. This order follows the LACP state machine as defined in IEEE 802.3ad.

Question 17

Drag and drop the steps of DMVPN Phase 2 NHRP resolution process into the correct order, from first to last.

Accepted Answer

Spoke sends NHRP Resolution Request to hub. In DMVPN Phase 2, the spoke sends an NHRP Resolution Request to the hub to learn the destination spoke's NBMA address. The hub forwards the request to the destination spoke, which replies with an NHRP Resolution Reply. The hub relays this reply back to the originating spoke. Finally, the originating spoke installs the NHRP shortcut entry and can initiate a direct tunnel to the destination spoke.

Question 18

Which three statements about error handling and debugging in Python network automation scripts are true? (Choose three.)

Accepted Answer

The try-except block allows a script to handle connection timeouts without crashing.. Correct answers: B, C, and D. B is correct because try-except blocks allow the script to handle exceptions gracefully without crashing. C is correct because logging provides a structured way to record events and errors for later analysis. D is correct because print statements are a simple debugging technique to output variable values during development. A is incorrect because 'pass' is a no-op statement that silently ignores exceptions, which is not recommended for production code. E is incorrect because the continue statement is used in loops to skip to the next iteration, not for error handling.

Answer

Using 'pass' in an except block is a best practice to ignore errors in production scripts.

Answer

The continue statement is used to handle exceptions in Python.

Question 19

Drag and drop the steps of ISE RADIUS policy evaluation order into the correct order, from first to last.

Accepted Answer

ISE receives RADIUS Access-Request from NAD. Cisco ISE evaluates RADIUS policies in a specific order: first authentication policies, then authorization policies (based on conditions), and finally the default rule if no match is found. This ensures proper access control.

Question 20

A network engineer configures SNMPv2c on a Cisco switch to send traps to an NMS at 192.168.1.100 with community 'monitor'. The engineer also configures 'snmp-server enable traps snmp linkdown linkup'. The NMS receives link traps but not authentication failure traps. The engineer has not configured any access control. What is the most likely reason?

Accepted Answer

Authentication failure traps are disabled by default and must be explicitly enabled.. On Cisco IOS, authentication failure traps are not enabled by default even when 'snmp-server enable traps snmp' is configured. The engineer explicitly enabled 'linkdown' and 'linkup' traps, but authentication failure traps require the additional keyword 'authentication' in the 'snmp-server enable traps snmp' command. Without this, the switch will not generate SNMP authenticationFailure notifications (RFC 1157) when an SNMP request uses an invalid community string.

Answer

The NMS is not configured to receive authentication failure traps.

Answer

The community string 'monitor' has read-write access, which suppresses authentication traps.

Answer

The switch must be configured with 'snmp-server trap-source' to send authentication traps.