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 slate disabled
D.
dedicated EPG for native VLAN
E.
static binding of native VLAN in all existing EPGs
i think the answer is A and D
1. Create a special MST EPG and map it to all ports facing non-ACI switches that run MST. This ensures that ACI does not drop MST BPDUs.
2. Navigate to Fabric > Access Policies > Policies > Switch > Spanning-Tree > default and create MST region policies that include the MST region names, MST instance IDs, revision IDs, and relevant VLAN encapsulations. This ensures that ACI knows which EPGs to flush when it receives a TCN and also out of which ports it should forward MST BPDUs.
A & D is correct.
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
Answer is A and D
[To accept traffic for any VLAN, the VLAN needs to be previsioned, either by a statically assigned port and VLAN to an EPG, or by the EPG being provisioned dynamically by the APIC when there is integration between the APIC and Virtual Machine Manager (VMM), (such as vCenter or Microsoft SCVMM). As a result, to ensure MST BPDU is flooded to the desired ports, the user needs to create an EPG to carry the BPDU]
This answer is not apt - ---> E. static binding of (native VLAN)* in all existing EPGs
Answer is D and E
Additional configuration is required in order for Multiple Spanning Tree (MST) BPDU to be flooded properly. The BPDU frame for Per-VLAN Spanning Tree (PVST) and Rapid Per-VLAN Spanning Tree (RPVST) have a VLAN tag. The ACI leaf can identify which EPG the BPDU needs to be flooded based on the VLAN tag in the frame. However, for MST (802.1s), BPDU frames don’t carry a VLAN tag and they 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 ACI fabric. By default there is no native VLAN enabled on the ACI fabric. To accept traffic for any VLAN, the VLAN needs to be previsioned, either by a statically assigned port and VLAN to an EPG, or by the EPG being provisioned dynamically by the APIC when there is integration between the APIC and Virtual Machine Manager (VMM), (such as vCenter or Microsoft SCVMM). As a result, to ensure MST BPDU is flooded to the desired ports, the user needs to create an EPG to carry the BPDU. As shown in Figure 71, the mode needs to be “native” given that the BPDU frame is untagged.
I agree DE, der this for further details: https://community.cisco.com/t5/data-center-documents/spanning-tree-mst-switches-interaction-with-aci/ta-p/3146184
upvoted 3 times
...
...
This section is not available anymore. Please use the main Exam Page.300-620 Exam Questions
Log in to ExamTopics
Sign in:
Community vote distribution
A (35%)
C (25%)
B (20%)
Other
Most Voted
A voting comment increases the vote count for the chosen answer by one.
Upvoting a comment with a selected answer will also increase the vote count towards that answer by one.
So if you see a comment that you already agree with, you can upvote it instead of posting a new comment.
thiyagas
Highly Voted 3 years, 9 months agonikomski
3 years, 9 months agoMohitkrsh84
3 years, 8 months agosailorsoul
Most Recent 9 months, 1 week agoGab99
2 years agorsm123th
2 years, 4 months agothomyohan
3 years, 4 months ago[Removed]
3 years, 9 months agohybersat
3 years, 9 months ago