Cisco CCNP Data Center 300-620 Questions & Answers

• Question 171:

  Refer to the exhibit.

  

  An engineer is deploying a Cisco ACI environment but experiences a STP loop between switch1 and switch2. Which configuration step is needed to break the STP loop?

  A. Configure a Layer 2 external bridged network on the interfaces facing the MST switches.

  B. Enable the native VLAN on the interfaces facing the MST switches using static ports in a dedicated EPG.

  C. Enable BPDU filter under the STP interface policy on the interfaces facing the MST switches.

  D. Configure the STP instance to VLAN mapping under the switch STP policy.

  Correct Answer: B

  BPDU frames in MST are sent on the Native Vlan (these are sent untagged), and not on a per-vlan basis as is the case with RPVST and PVST. This means we will have to make configuration specifically to accommodate for these differences

  in the ACI Fabric.

  To deal with the untagged MST BPDUs, you’ll need to configure a couple of things differently than what you do when dealing with RPVST or PVST.

  Create a Switch Policy Group for your MST region – Under Fabric Access Policies, you’ll need to create a Switch Policy Group (note – I’m not talking about Interface Policy Groups). For this Policy Group, you’ll create a Spanning-tree policy

  and add in information about your MST region.

  Native Vlan EPG – For ACI, in your Tenant where you Layer-2 connection resides, you will need to create a specific EPG to carry the MST BPDUs. The static path bindings for your Legacy switches will be configured as dot1p (native). Failure

  to do this could very likely result in a loop.

• Question 172:

  Refer to the exhibit.

  

  An engineer must configure an L3Out peering with the backbone network. The L3Out must forward unicast and multicast traffic over the link. Which two methods should be used to configure L3Out to meet these requirements? (Choose two.)

  A. Layer 3 routed port

  B. VPC with SVI

  C. port channel with SVI

  D. Layer 3 routed subinterface

  E. Layer 3 floating SVI

  Correct Answer: AD

• Question 173:

  An engineer must configure a group of servers with a contract that uses TCP port 80. The EPG that contains the web servers requires an external Layer 3 cloud to initiate communication. Which action must be taken to meet these requirements?

  A. Configure the EPG as a provider and L3 out as consumer of the contract.

  B. Configure OSPF to exchange routes between the L3 out and EPG.

  C. Configure a taboo contract and apply it to the EPG.

  D. Configure the EPG as a consumer and L3 out as a provider of the contract.

  Correct Answer: A

• Question 174:

  The unicast routing feature is enabled on the bridge domain. Which two conditions enable the Cisco ACI leaf to learn a source IP as a local endpoint? (Choose two.)

  A. Through Ethernet traffic received in a bridge domain.

  B. IP traffic routed through an SVI.

  C. Through VXLAN traffic received on the uplink.

  D. IP traffic routed through a Layer 3 Out.

  E. Through ARP received on an SVI.

  Correct Answer: BE

• Question 175:

  When does the Cisco ACI leaf learn a source IP or MAC as a remote endpoint?

  A. When VXLAN traffic arrives on a leaf fabric port from the spine and outer source IP is in the Layer 3 Out EPG subnet range.

  B. When VXLAN traffic arrives on a leaf fabric port from the spine and outer source IP is in the bridge domain subnets range.

  C. When VXLAN traffic arrives on a leaf fabric port from the spine and inner source IP is in the Layer 3 Out EPG subnet range.

  D. When VXLAN traffic arrives on a leaf fabric port from the spine and inner source IP is in the bridge domain subnets range.

  Correct Answer: D

  Inner source is BD subnet. Outer address is VXLAN TEP.

• Question 176:

  Refer to the exhibit.

  

  Which Adjacency Type value should be set when the client endpoint and the service node interface are in a different subnet?

  A. Routed

  B. Unicast

  C. L3Out

  D. L3

  Correct Answer: D

• Question 177:

  Which endpoint learning operation is completed on the ingress leaf switch when traffic is received from a Layer 3 Out?

  A. The source MAC address of the traffic is learned as a local endpoint.

  B. The source MAC address of the traffic is learned as a remote endpoint.

  C. The source IP address of the traffic is learned as a remote endpoint.

  D. The source IP address of the traffic is learned as a local endpoint.

  Correct Answer: A

• Question 178:

  An engineer must connect Cisco ACI fabric using Layer 2 with external third-party switches. The third-party switches are configured using 802.1s protocol. Which two constructs are required to complete the task? (Choose two.)

  A. spanning tree policy for mapping MST instances to VLANs

  B. MCP policy with PDU per VLAN enabled

  C. MCP instance policy with administrative state disabled

  D. dedicated EPG for native VLAN

  E. static binding of native VLAN in all existing EPGs

  Correct Answer: AD

  MST (IEEE 802.1s), BPDU frames do not carry a VLAN tag, and the BPDUs are sent over the native VLAN. Typically, the native VLAN is not used to carry data traffic, and the native VLAN may not be configured for data traffic on the Cisco ACI fabric. As a result, to help ensure that MST BPDUs are flooded to the desired ports, the user must create an EPG (an MST EPG) for VLAN 1 as native VLAN to carry the BPDUs. This EPG connects to the external switches that run MST.

  In addition, the administrator must configure the mapping of MST instances to VLANs to define which MAC address table must be flushed when a Topology Change Notification (TCN) occurs. When a TCN event occurs on the external Layer 2 network, this TCN reaches the leafs to which it connects via the MST EPG, and flushes the local endpoint information associated with these VLANs on these leafs; as result, these entries are removed from the spine-proxy mapping database.

  https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-737909.html

• Question 179:

  Regarding the MTU value of MP-BGP EVPN control plane packets in Cisco ACI, which statement about communication between spine nodes in different sites is true?

  A. By default, spine nodes generate 9000-bytes packets to exchange endpoints routing information. As a result, the Inter-Site network should be able to carry 9000-bytes packets.

  B. By default, spine nodes generate 1500-bytes packets to exchange endpoints routing information. As a result, the Inter-Site network should be able to carry 1800-bytes packets.

  C. By default, spine nodes generate 1500-bytes packets to exchange endpoints routing information. As a result, the Inter-Site network should be able to carry 1500-bytes packets.

  D. By default, spine nodes generate 9000-bytes packets to exchange endpoints routing information. As a result, the Inter-Site network should be able to carry 9100-bytes packets.

  Correct Answer: D

  Maximum transmission unit (MTU) of Multiprotocol Border Gateway Protocol (MP-BGP) Ethernet Virtual Private Network (EVPN) control plane communication between spine nodes in different sites - By default, the spine nodes generate 9000-byte packets to exchange endpoint routing information. If that default value is not modified, the Inter Site Network (ISN) must support an MTU size of at least 9100 bytes. In order to tune the default value, modify the corresponding system settings in each APIC domain.

• Question 180:

  Which two dynamic routing protocols are supported when using Cisco ACI to connect to an external Layer 3 network? (Choose two.)

  A. iBGP

  B. VXLAN

  C. IS-IS

  D. RIPv2

  E. eBGP

  Correct Answer: AE

  Reference:

  https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/ACI_Best_Practices/b_ACI_Best_Practices/ b_ACI_Best_Practices_chapter_010010.html