350-601 Network Practice Test 8 — 15 Questions

Question 1

A data center engineer is configuring vPC on a pair of Cisco Nexus switches. The vPC peer-link is established but the vPC member ports remain suspended. After checking the configuration, the engineer notices that the vPC peer-keepalive link is not functioning. What is the most likely cause of the suspended member ports?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Peer-keepalive link failure causing dual-active detection issues. When the vPC peer-keepalive link fails, each vPC peer switch cannot detect whether the other peer is operational. This triggers the dual-active detection mechanism, causing the secondary switch to suspend its vPC member ports to prevent a split-brain scenario where both switches forward traffic for the same vPC VLAN. The suspended state is a protective measure until the peer-keepalive link is restored or the vPC role is resolved.

Answer

MTU mismatch on the peer-link

Answer

Mismatched vPC domain ID

Answer

Incorrect VLAN configuration on member ports

Question 2

In a spine-leaf architecture using eBGP as the routing protocol, what is the primary purpose of using eBGP rather than iBGP between spine and leaf switches?

Accepted Answer

To avoid the need for an IGP and simplify configuration. In a spine-leaf architecture using eBGP, the primary purpose is to avoid the need for an IGP (such as OSPF or IS-IS) and simplify configuration. eBGP between spine and leaf switches allows each leaf to be in a different private AS (e.g., 65001–650XX), and the spine can use the BGP AS_PATH to detect and prevent loops without requiring an underlying IGP. This eliminates the complexity of running a separate IGP for underlay routing, reducing operational overhead and configuration steps.

Answer

To enable faster convergence than OSPF

Answer

To support EVPN address families

Answer

To allow for unequal-cost load balancing

Question 3

An engineer is configuring MST on a pair of Cisco Nexus switches that will be part of a vPC domain. The vPC peer-link will carry multiple MST instances. Which MST parameter must be identical on both vPC peers to ensure proper operation?

Accepted Answer

MST region configuration (name, revision, mapping). In a vPC domain with MST, both peers must share an identical MST region configuration (name, revision number, and VLAN-to-instance mapping) to ensure they agree on which VLANs belong to which MST instance. Without matching region configurations, the switches would treat each other as being in different MST regions, breaking the common spanning tree topology required for the vPC peer-link to properly carry multiple MST instances.

Answer

PortFast and BPDUguard settings

Answer

STP root bridge priority

Answer

STP path cost for instance 0

Question 4

Which VXLAN component is responsible for encapsulating and decapsulating Ethernet frames into UDP packets?

Accepted Answer

VTEP. The VTEP (VXLAN Tunnel Endpoint) is the device that performs encapsulation and decapsulation of Ethernet frames into UDP packets. It is the edge component in a VXLAN network that maps tenant traffic to VXLAN segments and handles the actual tunneling by adding the VXLAN header (including VNI) and outer UDP/IP headers.

Answer

VNI

Answer

VXLAN tunnel

Answer

VXLAN gateway

Question 5

In a Cisco ACI fabric, a tenant has multiple bridge domains with different subnets. The administrator wants to allow traffic between two EPGs in the same tenant but different bridge domains. Which ACI construct is required to enable communication?

Accepted Answer

Contracts with filters and subjects. In Cisco ACI, EPGs in different bridge domains are isolated by default. To enable communication between them, a contract must be applied that defines the allowed traffic. Contracts use filters and subjects to specify permitted protocols and ports, and are the only native ACI mechanism for inter-EPG communication across bridge domains within the same tenant.

Answer

Shared L3Out

Answer

VRF route leaking

Answer

VMM domain integration

Question 6

A data center architect is designing a spine-leaf network with 40 leaf switches and 8 spine switches. Each leaf has 40x25G downlinks to servers and 8x100G uplinks to spines. The oversubscription ratio from server to spine is calculated as (total downlink bandwidth) / (total uplink bandwidth). What is the oversubscription ratio for each leaf?

Accepted Answer

1.25:1. The oversubscription ratio for each leaf is calculated by dividing the total downlink bandwidth by the total uplink bandwidth. Each leaf has 40 downlinks at 25 Gbps each, totaling 1000 Gbps, and 8 uplinks at 100 Gbps each, totaling 800 Gbps. Thus, 1000 / 800 = 1.25, giving a 1.25:1 ratio.

Answer

1.5:1

Answer

2:1

Answer

0.8:1

Question 7

Which Cisco NX-OS feature allows automation and programmatic access to device configuration and monitoring using REST APIs?

Accepted Answer

NX-API. NX-API is the correct answer because it provides a REST-based API interface on Cisco NX-OS devices, allowing automation and programmatic access to configuration and monitoring via HTTP/HTTPS methods (GET, POST, PUT, DELETE). It exposes the device's CLI commands as RESTful API calls, enabling tools like Ansible, Postman, or custom scripts to interact with the switch without requiring SSH or direct CLI access.

Answer

Python scripting

Answer

Bash shell access

Answer

SNMP

Question 8

An engineer is configuring OSPF on a Cisco Nexus switch in a data center. The network consists of multiple point-to-point links. To improve convergence, the engineer wants to reduce the dead interval to 10 seconds. Which command sets the dead interval correctly?

Accepted Answer

ip ospf dead-interval 10. The 'ip ospf dead-interval 10' command directly sets the OSPF dead interval to 10 seconds on a Cisco Nexus switch. The dead interval is the time a router waits without receiving a hello packet before declaring the neighbor down, and reducing it to 10 seconds speeds up convergence on point-to-point links.

Answer

ip ospf dead-interval 30

Answer

ip ospf hello-interval 10

Answer

ip ospf dead-interval 40

Question 9

In a VXLAN EVPN fabric, a new server is connected to a leaf switch and requires Layer 2 connectivity to an existing VM on a different leaf. The engineer notes that the VTEP on the new leaf does not have a Type-2 route for the VM's MAC address. Which EVPN route type is used to advertise MAC addresses?

Accepted Answer

Type-2 (MAC/IP Advertisement). In VXLAN EVPN fabrics, Type-2 (MAC/IP Advertisement) routes are specifically used to advertise MAC addresses and their associated IP addresses between VTEPs. When a new leaf switch needs Layer 2 connectivity to a VM on a different leaf, it must learn the VM's MAC address via a Type-2 route from the remote VTEP. Without this route, the new leaf cannot populate its MAC table for that VM, preventing Layer 2 communication.

Answer

Type-5 (IP Prefix)

Answer

Type-1 (Ethernet Auto-discovery)

Answer

Type-3 (Inclusive Multicast Ethernet Tag)

Question 10

A network administrator is troubleshooting a vPC pair and needs to verify the operational status of the vPC peer-link. Which NX-OS command displays vPC status including peer-link and member port states?

Accepted Answer

show vpc. The 'show vpc' command (without any keyword) is the correct choice because it displays comprehensive vPC operational status, including the peer-link state (up/down), member port states, and vPC consistency status. This single command provides a high-level summary of all vPC components, making it the go-to command for initial troubleshooting of vPC peer-link and member port health.

Answer

show vpc brief

Answer

show vpc consistency-parameters

Answer

show vpc peer-keepalive

Question 11

In a Cisco ACI fabric, which component is responsible for managing the policy repository, fault monitoring, and API endpoints?

Accepted Answer

APIC controller. The APIC (Application Policy Infrastructure Controller) is the centralized management and policy engine in Cisco ACI. It maintains the policy repository (the logical and physical policy model), aggregates faults and events from all fabric nodes, and exposes northbound REST API endpoints for automation and integration. Without the APIC, the fabric cannot enforce policies or provide a single point of management.

Answer

DCNM

Answer

Spine switch

Answer

Leaf switch

Question 12

Which VLAN trunking protocol is used by default on Cisco Nexus switches to carry multiple VLANs over a single link?

Accepted Answer

802.1Q. 802.1Q is the IEEE standard trunking protocol used by default on Cisco Nexus switches to carry multiple VLANs over a single link. Unlike older Cisco switches that defaulted to ISL, Nexus switches exclusively support 802.1Q encapsulation for VLAN trunking, as ISL is not supported on the NX-OS platform.

Answer

VTP

Answer

DTP

Answer

ISL

Question 13

An engineer is implementing VXLAN in a data center. The network must handle BUM traffic without relying on IP multicast in the underlay. Which BUM handling method should be chosen?

Accepted Answer

Ingress replication. In VXLAN environments that must avoid IP multicast in the underlay, ingress replication is the correct BUM handling method. It replicates broadcast, unknown unicast, and multicast (BUM) traffic at the ingress VTEP and sends a copy to each remote VTEP via unicast encapsulation, eliminating the need for multicast group membership in the underlay.

Answer

ARP suppression

Answer

Head-end replication

Answer

Multicast group

Question 14

In a spine-leaf architecture, the oversubscription ratio between leaf switches and spine switches is 3:1. Each leaf has 48 x 10G server ports and 4 x 40G uplinks to the spine. What is the oversubscription ratio at the leaf level?

Accepted Answer

3:1. The oversubscription ratio at the leaf level is calculated by comparing the total bandwidth of the server-facing ports to the total bandwidth of the uplink ports. Each leaf has 48 x 10G server ports (480 Gbps) and 4 x 40G uplinks (160 Gbps). The ratio is 480:160, which simplifies to 3:1. This matches the given spine-leaf oversubscription ratio, confirming that the leaf-level ratio is 3:1.

Answer

1:1

Answer

4:1

Answer

2:1

Question 15

Which NX-OS command is used to display the consistency status of Virtual Port Channel (vPC) parameters across both vPC peers?

Accepted Answer

show vpc consistency-parameters. The 'show vpc consistency-parameters' command is specifically designed to verify that all required VPC configuration parameters (such as allowed VLANs, STP settings, and port-channel modes) are identical on both VPC peers. Inconsistent parameters can cause VPC traffic disruption or failover issues, and this command provides a detailed per-interface or global consistency check.

Answer

show vpc peer-keepalive

Answer

show vpc brief

Answer

show running-config vpc