Free Practice Questions for Cisco 300-620 Exam

When implementing a connection that represents an external bridged network, the configurations used are Layer 2 outside (Option B) and Static path binding (Option D)12. Layer 2 outside is typically used to connect a bridged external network trunk switch to a leaf switch in the ACI fabric, while static path binding is used to assign specific ports on a leaf switch to an external bridged network12.

In a Cisco ACI fabric, Spanning Tree Protocol (STP) Bridge Protocol Data Units (BPDUs) that are generated by an external switch, such as Switch2 in this scenario, are indeed forwarded across the fabric. This allows externally connected switches to maintain a loop-free topology. While Cisco ACI does not participate in STP as it uses its own protocols and mechanisms for loop prevention within the fabric, it will forward STP BPDUs across End Point Groups (EPGs) on which they are received1. This ensures that the connected external switches can still use STP for their loop prevention mechanisms.

References :=

Cisco Community Discussion on STP BPDUs in ACI1

In a Cisco ACI Multi-Site setup, back-to-back spine connectivity is limited to a direct connection between two sites. This design simplifies inter-site communication by avoiding the need for an intermediate Inter-Pod Network (IPN) or Multi-Site Orchestrator.

 Changing the Layer 2 unknown unicast policy from Flood to Hardware Proxy results in the traffic being forwarded to one of the spines to perform as a spine proxy4. If the spine proxy also does not know the address, the packet is discarded4.

To implement management policy and data plane separation in the Cisco ACI fabric, the ACI object that must be created in Cisco APIC is a Bridge domain

 The minimum number of APICs that Cisco recommends to deploy in a production cluster is 3 (Option B). This recommendation is based on the need for high availability and redundancy in a production environment.

When deploying a new Cisco ACI Multi-Pod setup, it’s crucial to ensure that the Tunnel Endpoint (TEP) pool of the new pod is routable across the Inter-Pod Network (IPN). This allows the TEP addresses to be reachable across the pods, facilitating communication between them. Additionally, increasing the Maximum Transmission Unit (MTU) for all IPN routers is necessary to support the larger frame size required by VXLAN encapsulation, which is typically above the standard Ethernet MTU of 1500 bytes.

References :=

Cisco ACI Multi-Pod Configuration Guide

Cisco ACI Best Practices Guide

o protect the ACI fabric from spanning-tree loops, the feature that must be enabled on the ACI leaf ports is BPDU Guard 

To complete the task of configuring a Layer 3 connection to the WAN router and allowing hosts in the production VRF to access WAN subnets, the engineer should configure the Export Route Control Subnet scope for the external EPG. This setting allows the subnets associated with the external EPG to be advertised to external routers, enabling connectivity to the WAN.

When upgrading the Cisco ACI fabric through an intermediate release, the following steps should be taken:

Upgrade the APICs to an interim release: This is the first step to ensure that the APICs are running a stable version that is compatible with both the current and the targeted release1.

Upgrade the switches to an interim release: After the APICs are upgraded, the next step is to upgrade the leaf and spine switches to the same interim release. This ensures that the entire fabric is running on a compatible version before moving to the targeted release1.

Upgrade the APICs to the targeted release: Once the fabric is stable on the interim release, the APICs can be upgraded to the targeted release. It’s important to verify that the APICs are fully operational before proceeding to upgrade the switches1.

Upgrade the leaf and spine switches to the targeted release: The final step is to upgrade the leaf and spine switches to the targeted release. This should be done after the APICs have been successfully upgraded and are stable on the targeted release1.

By following these steps, the customer can successfully upgrade the Cisco ACI fabric to the new code release that includes the desired feature.