350-601 Network Practice Test 12 — 15 Questions

Question 1

An engineer is designing an ACI fabric and needs to provide connectivity to an external Layer 3 network. Which construct must be configured to achieve this?

Accepted Answer

L3Out. To connect an ACI fabric to an external Layer 3 network, you must configure an L3Out. An L3Out defines the external routed connectivity by associating a VRF with external interfaces, routing protocols (e.g., OSPF, BGP, EIGRP), and subnets that are advertised into or from the fabric. This construct allows ACI to exchange routes with the external Layer 3 domain.

Answer

VMM domain

Answer

EPG

Answer

VXLAN tunnel

Question 2

Which BGP variant is commonly used in spine-leaf fabrics to advertise EVPN routes for VXLAN?

Accepted Answer

MP-BGP with EVPN address family. MP-BGP with the EVPN address family (AFI 25 / SAFI 70) is the control-plane protocol used in VXLAN spine-leaf fabrics to advertise MAC/VTEP reachability, host routes, and integrated routing and bridging (IRB) information. This allows the spine to act as a route reflector, distributing EVPN type-2 (MAC/IP) and type-3 (IMET) routes to all leaf nodes, enabling efficient, loop-free overlay forwarding.

Answer

OSPF with opaque LSA

Answer

eBGP with standard IPv4 unicast

Answer

iBGP with standard IPv4 unicast

Question 3

In a data center running MST, which region configuration parameter must match on all switches for them to be part of the same region?

Accepted Answer

Region name, revision number, and VLAN-to-instance mapping. In Multiple Spanning Tree (MST), switches must agree on three parameters to belong to the same MST region: the region name, the revision number, and the VLAN-to-instance mapping. These parameters are exchanged in MST BPDUs, and if any differ, the switches treat each other as being in different regions, which can lead to suboptimal or incorrect spanning-tree behavior.

Answer

Spanning-tree mode

Answer

Bridge priority

Answer

Max-age and hello time

Question 4

An engineer is troubleshooting a vPC consistency check failure. Which parameter must be identical on both vPC peer switches to avoid a consistency check violation for a vPC member port?

Accepted Answer

Allowed VLAN list on the port channel. In a vPC environment, the allowed VLAN list on the port channel must be identical on both peer switches for a vPC member port. If the lists differ, the vPC consistency check fails, causing the port to be suspended or placed in a consistency-check failure state. This ensures that both peers forward the same set of VLANs across the vPC, preventing asymmetric forwarding and potential loops.

Answer

STP root guard setting

Answer

MTU size

Answer

Spanning-tree port type

Question 5

In a VXLAN overlay, what is the role of the VXLAN Network Identifier (VNI)?

Accepted Answer

It identifies the overlay Layer 2 network segment. The VXLAN Network Identifier (VNI) is a 24-bit field in the VXLAN header that uniquely identifies an overlay Layer 2 network segment, allowing multiple isolated Layer 2 domains to coexist over a shared Layer 3 underlay. It is analogous to a VLAN ID in traditional networking but provides up to 16 million segments, enabling scalable network virtualization.

Answer

It identifies the VXLAN tunnel source and destination IP

Answer

It is the multicast group address for BUM traffic

Answer

It is used for ECMP load balancing

Question 6

Which NX-OS command is used to display the current OSPF neighbor states?

Accepted Answer

show ip ospf neighbors. The 'show ip ospf neighbors' command is the correct NX-OS command to display the current OSPF neighbor states, including the neighbor ID, interface, state (e.g., FULL, 2WAY, DOWN), and adjacency details. This command directly queries the OSPF process for the neighbor state machine, which is essential for verifying OSPF adjacency formation and troubleshooting Layer 3 connectivity.

Answer

show ip route ospf

Answer

show ospf database

Answer

show ip ospf interface

Question 7

In ACI, a contract is defined between two EPGs. Which component specifies the type of traffic allowed?

Accepted Answer

Subject. A contract contains subjects, which include filters that define traffic types.

Answer

VRF

Answer

Filter

Answer

Tenant

Question 8

A data center designer is evaluating oversubscription ratios in a spine-leaf topology with 40 leaf switches and 4 spine switches. Each leaf has 4x100G uplinks to spines, and each spine has 40x100G downlinks. The leaf switches have 48x25G server ports. What is the oversubscription ratio from the server ports to the spine uplinks?

Accepted Answer

3:1. The oversubscription ratio is calculated by comparing total server bandwidth to total uplink bandwidth. Each leaf has 48x25G server ports = 1200G, and 4x100G uplinks = 400G, giving a leaf-level ratio of 3:1 (1200:400). Since all leaves are identical and the spine count doesn't affect the leaf-level ratio, the overall ratio remains 3:1.

Answer

2:1

Answer

4:1

Answer

5:1

Question 9

An engineer needs to automate a repetitive configuration task on a Nexus switch. Which method is most suitable for programmatic access?

Accepted Answer

NX-API. NX-API provides a RESTful interface that allows programmatic access to Nexus switches using HTTP/HTTPS methods (GET, POST, DELETE) with JSON or XML payloads. This makes it the most suitable method for automating repetitive configuration tasks because it supports modern scripting languages (Python, Ansible) and enables idempotent, structured configuration changes without requiring interactive CLI sessions.

Answer

FTP file transfer

Answer

CLI scripting with Tcl

Answer

SNMP v3

Question 10

A network engineer is configuring 802.1Q trunking between a Nexus switch and a server. Which TWO statements are true regarding 802.1Q trunking?

Accepted Answer

The VLAN ID is 12 bits long. 802.1Q trunking uses a 4-byte tag to carry VLAN information, but the native VLAN is sent untagged, so not all frames receive the tag. The VLAN ID field is 12 bits (B), and after tagging, the FCS must be recalculated (E). Option A is false because the native VLAN is untagged. Option C is false because only non-native VLAN frames are tagged. Option D is false because trunks can carry multiple VLANs.

Answer

The native VLAN is tagged by default

Answer

A 4-byte tag is inserted into the Ethernet frame

Answer

Trunks can only carry one VLAN

Question 11

In an ACI fabric, which THREE components are required to define a policy that allows communication between two EPGs?

Accepted Answer

Contract. A contract is required because it defines the rules (filters, subjects, and actions) that govern traffic between EPGs. Without a contract, no communication is allowed between EPGs, even within the same tenant. The consumer EPG initiates the communication and the provider EPG hosts the service, so both are mandatory endpoints of the contract relationship.

Answer

L3Out

Answer

Tenant

Question 12

An engineer is implementing VXLAN with a centralized routing gateway. Which TWO statements are correct about BUM traffic handling?

Accepted Answer

Ingress replication sends a copy of the BUM packet to each remote VTEP via unicast. In a VXLAN centralized routing gateway deployment, ingress replication is a valid method for handling BUM traffic where the ingress VTEP sends a unicast copy of the BUM packet to each remote VTEP. This is correct because it eliminates the need for multicast in the underlay, making option B accurate. Ingress replication consumes more bandwidth on the source VTEP uplinks than multicast because it generates multiple unicast copies, whereas multicast sends a single stream that is replicated by the network, making option C correct.

Answer

Multicast in the underlay is always required for BUM traffic

Answer

Only the ingress VTEP handles BUM traffic

Answer

BUM traffic is never flooded to all VTEPs

Question 13

Which protocol is used to carry VXLAN encapsulation and facilitates the exchange of MAC reachability information between VTEPs in a VXLAN EVPN fabric?

Accepted Answer

MP-BGP. In a VXLAN EVPN fabric, MP-BGP (Multiprotocol BGP) is the control plane protocol used to advertise MAC reachability information between VTEPs. It carries VXLAN encapsulation information via the BGP EVPN address family (AFI L2VPN / SAFI EVPN), enabling VTEPs to learn remote MAC addresses and VNI mappings without relying on data-plane flooding.

Answer

eBGP

Answer

OSPF

Answer

PIM

Question 14

An engineer configures vPC on a pair of Nexus switches. The vPC peer-keepalive link fails, but the vPC peer-link remains operational. What is the expected behavior?

Accepted Answer

The vPC domain remains operational with both switches forwarding traffic.. When the vPC peer-keepalive link fails but the peer-link remains up, the vPC domain continues to operate normally because the peer-link is used for control-plane synchronization and data-plane forwarding. The peer-keepalive is only a secondary heartbeat to detect a dual-active scenario when the peer-link is down. Since the peer-link is still functional, both switches can exchange vPC consistency parameters and forward traffic without risk of loops.

Answer

Both switches suspend all vPC member ports to avoid loops.

Answer

The primary switch reloads to prevent a split-brain scenario.

Answer

The secondary switch suspends its vPC member ports.

Question 15

In a VXLAN BGP EVPN fabric, which component is responsible for handling BUM traffic using ingress replication, and how does the VTEP learn the list of remote VTEPs to replicate to?

Accepted Answer

The ingress VTEP learns remote VTEPs via MP-BGP EVPN Type 3 routes.. In a VXLAN BGP EVPN fabric, ingress replication is the default method for handling BUM traffic, where the ingress VTEP replicates packets and sends unicast copies to each remote VTEP. The ingress VTEP learns the list of remote VTEPs from MP-BGP EVPN Type 3 routes (Inclusive Multicast routes), which advertise the VNI and the originating VTEP's IP address, allowing the ingress VTEP to build its replication list.

Answer

The ingress VTEP learns remote VTEPs via IGMP snooping.

Answer

The egress VTEP sends unicast copies to all other VTEPs.

Answer

The spine switch performs replication to all leaf VTEPs.