350-601 Network Practice Test 4 — 15 Questions

Question 1

An engineer is configuring VXLAN bridging and routing on a Cisco Nexus 9000 switch. Which configuration is required to enable inter-VNI routing?

Accepted Answer

Configure anycast gateway MAC.. Inter-VNI routing requires a shared anycast gateway MAC address across all VTEPs in the same VXLAN fabric. This allows the switch to respond to ARP requests for the gateway IP and forward traffic between different VNIs without relying on a traditional routed interface. The anycast gateway MAC is configured under the VLAN interface (SVI) using the 'fabric forwarding anycast-gateway-mac' command.

Answer

Configure a VLAN interface under the bridge domain.

Answer

Enable ip routing under VRF.

Answer

Configure a VRF and associate the VLAN interface to it.

Question 2

In a BGP EVPN deployment, route type 2 (MAC/IP advertisement) is used to advertise MAC addresses. What additional information is carried in route type 2 for IP routing?

Accepted Answer

IP address and MAC address. In BGP EVPN, route type 2 (MAC/IP Advertisement Route) is used to advertise both MAC addresses and their associated IP addresses. The additional information carried for IP routing is the IP address and the MAC address, enabling the control plane to support both Layer 2 bridging and Layer 3 routing (e.g., host route advertisement for IP-based forwarding). This is defined in RFC 7432, where the route type 2 NLRI includes a MAC address field and an optional IP address field.

Answer

IP address and route distinguisher

Answer

IP prefix and next-hop

Answer

MAC address and VNI

Question 3

Which two VXLAN control plane options are supported on Cisco Nexus 9000 switches? (Choose two.)

Accepted Answer

Multicast. VXLAN on Cisco Nexus 9000 switches supports both multicast-based control plane (using IGMP/PIM to flood BUM traffic) and MP-BGP EVPN (RFC 7432) as the control plane for distributing MAC/VTEP reachability. Multicast is the traditional method for handling BUM traffic in VXLAN fabrics, while MP-BGP EVPN provides a more scalable, standards-based control plane with host route advertisement and multi-tenancy.

Answer

OTV

Answer

Static VXLAN tunnel

Answer

OpenFlow

Question 4

An OSPF router in a broadcast network has not formed a neighbor relationship. What are three possible causes? (Choose three.)

Accepted Answer

MTU mismatch. In OSPF, an MTU mismatch prevents the formation of a neighbor relationship because OSPF routers compare the MTU value in Database Description (DBD) packets. If the receiving router's interface MTU is smaller than the DBD packet size, the packet is dropped, and the neighbor state remains stuck in EXSTART/EXCHANGE. This is a common issue on broadcast networks where different link types or misconfigured interfaces exist.

Answer

Authentication incorrect

Answer

Area ID mismatch

Question 5

Which two benefits does EVPN provide compared to traditional VPLS? (Choose two.)

Accepted Answer

Load balancing of traffic across multiple active paths. EVPN uses BGP to advertise MAC addresses and IP prefixes, enabling per-flow load balancing across multiple equal-cost paths via its all-active multi-homing capability. In contrast, traditional VPLS relies on a single active forwarder per site (using Spanning Tree Protocol or VPLS Multihoming), which prevents active-active load balancing and wastes bandwidth.

Answer

Simpler BGP configuration

Answer

Reduced MAC address learning

Answer

No need for MPLS

Question 6

Refer to the exhibit. A network engineer notices that traffic for VNI 10000 is not being encapsulated. What is the most likely reason?

Accepted Answer

VNI 10000 is not configured under the nve interface.. VNI 10000 must be explicitly mapped to an NVE interface under the 'interface nve1' configuration using the 'member vni 10000' command. Without this mapping, the NVE interface does not know which VNI to encapsulate traffic for, even if the VNI exists in the network. Option B correctly identifies this missing configuration as the most likely cause.

Answer

BGP EVPN is not configured.

Answer

The VRF association is incorrect.

Answer

The source-interface is not reachable.

Question 7

Refer to the exhibit. What is the most likely cause of neighbor 10.1.1.3 being stuck in EXSTART?

Accepted Answer

MTU mismatch between the interfaces.. In OSPF, the EXSTART state indicates that neighbors are negotiating the master/slave relationship and exchanging Database Description (DBD) packets. If the MTU of the interface on one side is larger than the MTU on the other, the larger DBD packet will be silently dropped, preventing the neighbor from progressing past EXSTART. This is a classic symptom of an MTU mismatch, as the OSPF adjacency will remain stuck in EXSTART or EXCHANGE.

Answer

Duplicate router ID.

Answer

OSPF network type mismatch.

Answer

The interface is configured as passive.

Question 8

Refer to the exhibit. A network engineer has configured a port-channel for OSPF adjacency. What additional configuration is required for the port-channel to operate correctly?

Accepted Answer

Configure the channel-group mode on member interfaces.. For a port-channel to form an OSPF adjacency, the member interfaces must be configured with a channel-group mode (e.g., 'channel-group 1 mode active') to bundle them into a logical port-channel interface. Without this, the interfaces remain individual Layer 2 or Layer 3 links, and OSPF cannot establish adjacency over the port-channel as a single logical link.

Answer

Set the OSPF priority.

Answer

No additional configuration needed.

Answer

Enable OSPF on the port-channel with `ip router ospf process`.

Question 9

A network engineer is troubleshooting high CPU utilization on a Nexus 9000 switch. Which command is most useful to identify the process consuming the most CPU?

Accepted Answer

show process cpu sort. The 'show process cpu sort' command on Nexus 9000 switches displays the current CPU utilization sorted by the process consuming the most CPU, allowing the engineer to quickly identify the top CPU consumer. This command provides a real-time, sorted list of processes with their CPU usage percentages, which is directly useful for troubleshooting high CPU utilization.

Answer

show processes cpu history

Answer

show system resources

Answer

show cpu usage

Question 10

A data center uses VPC between two Nexus switches. Which statement is true about the VPC peer-link?

Accepted Answer

It carries both data and control traffic.. The VPC peer-link is a critical component in a vPC domain, carrying both data traffic (e.g., traffic from orphan ports or traffic that must traverse the peer-link for forwarding) and control traffic (e.g., vPC keepalive messages and Cisco Fabric Services (CFS) synchronization). This dual role ensures that the two Nexus switches operate as a single logical entity for the downstream devices, providing loop-free Layer 2 multipathing.

Answer

It must be a single link.

Answer

It carries only control traffic.

Answer

It is used only for orphan ports.

Question 11

Which protocol is used by Cisco ACI fabric to distribute endpoint information among spines?

Accepted Answer

COOP. D is correct because the Cisco ACI fabric uses the Council of Oracle Protocol (COOP) specifically to distribute endpoint information (such as IP-to-MAC bindings and location) among spine switches. COOP operates as a lightweight, publish-subscribe protocol that runs between leaf and spine switches, ensuring that all spines maintain a consistent endpoint database without the overhead of a full routing protocol.

Answer

IS-IS

Answer

OSPF

Answer

BGP

Question 12

A network engineer is troubleshooting a VXLAN EVPN problem where some endpoints are not reachable. The output of 'show bgp l2vpn evpn' shows Type-3 routes but no Type-2 routes for a specific VNI. What should the engineer check?

Accepted Answer

The VLAN corresponding to the VNI has no active ports.. Type-3 routes (IMET routes) are used for BUM traffic forwarding and are advertised when the VNI is configured under the NVE interface, even if no endpoints are active. Type-2 routes (MAC/IP advertisement routes) are only generated when the switch learns a MAC address on a VLAN associated with that VNI. If Type-3 routes exist but Type-2 routes are missing, the VNI is correctly configured for the overlay, but no active ports in the corresponding VLAN are learning MAC addresses, preventing Type-2 route generation.

Answer

The route-target import/export is misconfigured.

Answer

BGP session is not established.

Answer

The VNI is not configured under the NVE interface.

Question 13

A Nexus 9000 switch is configured with VPC. The VPC keepalive link fails. What is the effect on the VPC domain?

Accepted Answer

The secondary switch suspends its VPC member ports.. In a VPC domain, the keepalive link is used to monitor the liveness of the peer switch, but it does not carry data traffic. When the keepalive link fails, the secondary switch cannot confirm the primary is alive, so it suspends its VPC member ports to prevent a dual-active scenario. The primary switch remains active and continues forwarding traffic normally because it assumes the secondary has failed.

Answer

Both switches suspend the VPC VLANs.

Answer

Both switches continue to forward traffic normally.

Answer

The primary switch becomes orphan.

Question 14

In a Cisco ACI fabric, a new EPG is created and associated with a bridge domain that has 'Unicast Routing' enabled. However, endpoints in that EPG cannot communicate with endpoints in other EPGs in the same VRF. What is missing?

Accepted Answer

A contract between the EPGs. In Cisco ACI, communication between EPGs within the same VRF is not allowed by default; it requires a contract. A contract defines the policies (allow/deny) and filters for traffic between EPGs. Without a contract, all traffic is dropped, even if the bridge domain has unicast routing enabled. Option C is correct because the missing element is the contract that explicitly permits inter-EPG communication.

Answer

The EPG must be attached to a Layer 3 outside

Answer

The bridge domain must have 'L3 Unknown Multicast Flooding' set

Answer

A route leak between bridge domains

Question 15

An engineer is troubleshooting BGP EVPN control plane. They issue 'show bgp l2vpn evpn' and see Type-3 routes but no Type-2 routes for any VNI. Which condition is most likely?

Accepted Answer

The VTEP has not learned any MAC addresses. Type-3 routes (Inclusive Multicast Ethernet Tag routes) are generated automatically when an EVPN VNI is configured, regardless of MAC learning. Type-2 routes (MAC/IP Advertisement routes) are only generated after the VTEP learns MAC addresses from data-plane traffic or from local endpoints. The absence of Type-2 routes with Type-3 present indicates the VTEP has not yet learned any MAC addresses for that VNI.

Answer

The overlay VNI is not mapped to a VLAN

Answer

The BGP neighbor is not from the same AS

Answer

The EVPN address-family is not enabled