300-620 Exam Results

To configure an L3Out peering with the backbone network that must forward both unicast and multicast traffic, the two methods that should be used are:

Layer 3 routed port (Option A): This method involves configuring a physical port on the Cisco ACI leaf switch as a Layer 3 interface, which is suitable for routing unicast and multicast traffic.

Layer 3 routed subinterface (Option D): This method involves configuring a subinterface under a physical port, which allows for traffic segregation and routing over the same physical link, supporting both unicast and multicast traffic.

These methods ensure that the L3Out can handle the required traffic types and maintain proper routing with the backbone network.

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centricinfrastructure/

guide-c07-743150.html#_L3Out_sStatic_rRoutes

https://www.cisco.com/ c/en/us/td/docs/switches/datacenter/aci/apic/sw/4-x/L3-configuration/Cisco-APIC-Layer-3-Networking-Configuration-Guide-401/Cisco-APIC-Layer-3-Networking-Configuration-Guide-401_chapter_010010.html

 To redirect traffic to the firewall using a one-armed policy-based redirect service insertion, the following configuration set should be used:

Configure a service graph: This involves defining the service graph template that represents the logical flow of traffic through network services.

Associate the service graph with All_Traffic_Allowed: By associating the service graph with the contract named All_Traffic_Allowed, traffic that matches the contract will be redirected through the service graph to the firewall device.

References :=

Cisco ACI Fabric Administration Guide, Release 4.2(1)

Cisco ACI Virtualization Guide, Release 4.2(1)

To enable connectivity for the external endpoints in the 172.16.1.0/24 subnet, the following actions should be taken:

Delete both external EPG subnets: This action removes any specific subnet configurations that might be causing routing issues or conflicts within the external EPG1.

Create the 0.0.0.0/0 subnet: By configuring a 0.0.0.0/0 subnet, you are effectively creating a default route that allows all traffic to be routed, ensuring that endpoints in any subnet, including the 172.16.1.0/24 subnet, can reach internal endpoints1.

This configuration change addresses the issue where traffic from the 172.16.1.0/24 subnet is not reaching the internal endpoints, likely due to a lack of a default route or misconfigured subnets within the external EPG

To break the STP loop between switch1 and switch2 in a Cisco ACI environment, enabling BPDU filtering on the interfaces facing the MST (Multiple Spanning Tree) switches is the necessary step. BPDU filtering prevents BPDUs from being sent or received through a port, which effectively stops the STP process on those ports and breaks the loop1.

When BPDU filtering is enabled on an interface, the switch does not send any BPDUs and ignores any BPDUs it receives on that interface. This can be used to prevent unwanted STP negotiations on ports where loops are not expected to happen or where STP is not desired1.

References :=

Use of ACI Operation with L2 Switches and Spanning Tree Link Types - Cisco1