Implementing Cisco Application Centric Infrastructure - Advanced (DCACIA) v 1.2 Quiz Questions and Answers
Answer :
dynamic endpoint attach
Explanation :
Option A is INCORRECT because:<br/>- ARP gleaning is a feature used by Cisco ACI to learn about endpoints when they initiate ARP traffic. It does not configure firewall ACLs automatically when new endpoints are attached.<br/><br/>Option B is CORRECT because:<br/>- Dynamic endpoint attach is a feature that allows Cisco ACI to automatically update policies, including firewall ACLs, when endpoints are added or moved within an EPG (Endpoint Group), ensuring security policies are consistently applied.<br/><br/>Option C is INCORRECT because:<br/>- Hardware proxy is a mechanism in Cisco ACI for resolving ARP requests within the fabric without involving spine or leaf switches. It does not deal with the automatic configuration of firewall ACLs.<br/><br/>Option D is INCORRECT because:<br/>- Network-stitching is a term that can refer to connecting different network segments or services together. While this may involve DHCP, VXLAN tunnels, or L4-L7 service insertion, it does not entail configuring firewall ACLs automatically when endpoints join an EPG.
Option A is INCORRECT because having only one APIC does not provide any redundancy or load balancing, both of which are important in a production environment.<br/><br/>Option B is CORRECT because Cisco recommends deploying three APICs in a production cluster for optimum performance. This provides both redundancy and load balancing, ensuring efficient performance and business continuity.<br/><br/>Option C is INCORRECT because while deploying five APICs won't harm the cluster, it's an overkill and not necessary. Three is the golden number as it ensures redundancy and load distribution, without creating unnecessary complexity or expenses.<br/><br/>Option D is INCORRECT because although deploying two APICs provides redundancy, it does not efficiently balance the load as one APIC will always be idle. Moreover, it also does not provide the quorum needed in case of a failure. Therefore, three APICs are recommended.
Enable and assign infra MP-BGP Route Reflectors in the fabric
Explanation :
To redistribute OSPF-learned external routes throughout the ACI fabric, infra MP-BGP route reflectors must be enabled and assigned so that external routes learned by border leaf switches are distributed to all leaf switches via MP-BGP. Manual OSPF configuration on every leaf is not required; assigning L3Out to a BD and advertising subnets deals with internal subnet advertisement; marking Export Route Control Subnet affects what routes are advertised externally, not internal ACI route distribution.
COOP (Council of Oracle Protocol) is used in Cisco ACI to distribute endpoint location information (also known as proxy database information) between leaf switches and spine switches. This allows ACI to track the location of endpoints for efficient packet forwarding. While IS-IS establishes the fabric topology and MP-BGP distributes external routes, COOP is specifically responsible for endpoint location exchange. OSPF is not used for endpoint information in ACI.
Configure the 'Shared Route Control Subnet' scope on the L3Out subnet in VRF-A.
Explanation :
The 'Shared Route Control Subnet' scope must be configured on the L3Out subnet in VRF-A to leak the route (i.e., make it available through MP-BGP route targets) to another VRF. Contracts need 'Tenant' or 'Global' scope, not 'Application'. 'Import Route Control Subnet' is not used for VRF route leaking; it's used for route filtering on import. 'Policy Control Enforcement Direction' is unrelated to the ability to leak routes between VRFs.
It specifies which subnets will be advertised (exported) from ACI to external routers via L3Out.
Explanation :
The 'Export Route Control Subnet' scope tells ACI which subnets to advertise (export) from the fabric to external routers via the L3Out. This is essential in Transit Routing use cases to allow ACI to act as a transit network, redistributing specific external routes from one L3Out to another. It does not control route importing, contract enforcement, or summarization directly.
The IPN must provide Layer 3 connectivity between spines in different pods and support multicast routing or headend replication for BUM traffic.
Explanation :
The Inter-Pod Network (IPN) in Cisco ACI Multi-Pod must provide Layer 3 connectivity between spine switches of different pods, and must support multicast routing or headend replication to carry BUM (broadcast, unknown unicast, multicast) traffic between pods. Layer 2-only or MPLS are not required. The IPN is a required component of the Multi-Pod architecture.
Explicitly configure the directly connected subnet with 'External Subnets for the External EPG' scope.
Explanation :
By default, directly connected subnets may be assigned pcTag 1 (contract bypass) in some hardware, permitting traffic to bypass contract enforcement. Explicitly configuring the directly connected subnet with 'External Subnets for the External EPG' scope ensures pcTag classification matches the desired L3Out EPG and enforces contract policy as intended.
To advertise a specific subnet from ACI to an external routed domain.
Explanation :
The "Export Route Control Subnet" scope is used to control which subnets (including BD subnets or transit routes) are advertised (exported) from ACI to the external network via L3Out. It does NOT control contract enforcement (A), does not restrict BDs to internal–it is for external advertisement, and does not restrict route installation (D).
Configuring at least one BGP Route Reflector spine per Pod
Explanation :
In ACI Multi-Pod, each Pod must have at least one (preferably two) route-reflector spines configured to ensure MP-BGP distributes external routes throughout the fabric. Overlapping VLAN IDs are not required, nor are L2 border leaves for inter-Pod traffic, and disabling MP-BGP infra VRF would prevent proper route distribution.
