300-620 Exam Dumps - Cisco CCNP Data Center Questions and Answers

On the egress leaf switch, when traffic is received from an L3Out, no source MAC or IP address of the traffic is learned as a remote endpoint1. The Cisco ACI fabric does not learn the IP addresses from the data plane in an L3Out domain; instead, it uses ARP to resolve next-hop IP and MAC relationships to reach the prefixes behind external routers1.

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.

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 whichthey 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

The two protocols used for fabric discovery in Cisco ACI are LLDP (Link Layer Discovery Protocol) and ISIS (Intermediate System to Intermediate System). LLDP is used for neighbor discovery on the data link layer, while ISIS is a routing protocol used for reachability between the TEP IPs (VTEPs) within the ACI fabric23.

The two essential components of a Cisco ACI Virtual Machine Manager (VMM) domain policy configuration are:

VMM domain profile1.

EPG association1.

https://www.cisco.com/c/en/us/td/docs/switches/datac enter/aci/apic/sw/1-x/aci-fundamentals/b_ACI-Fundamentals/b_ACI-Fundamentals_chapter_01011.html#concept_74EFC437C0AA44A391676F70ACE59DF3

When a pre-provision immediacy is used, the policy is downloaded to the Cisco ACI leaf switch and programmed into the hardware policy Content Addressable Memory (CAM) as soon as the change isimplemented on the Cisco Application Policy Infrastructure Controller (APIC). This means that the policy is ready on the leaf switch before any endpoints are actually connected.

An EPG is extended outside of the ACI fabric by statically assigning a VLAN ID to a leaf port in an EPG. This method maps the traffic received on the leaf port to the EPG, and the policy for this EPG is enforced