Cisco 300-630 Implementing Cisco Application Centric Infrastructure - Advanced (DCACIA) Exam Practice Test

An application-centric design in Cisco ACI focuses on the application requirements and interactions between different application components. In this design, EPGs (Endpoint Groups) represent different application tiers, such as web, application, and database tiers. This approach allows for a more flexible and scalable network configuration that aligns with the application architecture, enabling policies to be applied based on the application’s needs rather than the network topology. References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

 In Cisco ACI, to reassign a unique globally scoped pcTag to an Endpoint Group (EPG) that provides a global contract, one should configure subnets that are shared between VRFs (Virtual Routing and Forwarding instances) (Option C). This action allows subnets associated with an EPG to be shared across different VRFs while maintaining unique identifiers for application endpoint groups within the global scope of the fabric.

References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )

To connect two nonsilient servers in active/standby mode to two ACI leaves, you should implement a virtual PortChannel (vPC) on the ACI leaves. vPC provides high availability and load balancing for server connections.

References := Cisco APIC Layer 2 Networking Configuration Guide, Release 5.2(x)

The control plane TEP (Tunnel Endpoint) IP address is a unique IP address assigned to each spine node within a Cisco ACI fabric. This IP address is used to establish MP-BGP EVPN (Multiprotocol Border Gateway Protocol Ethernet VPN) and VPNv4 (VPN version 4) adjacencies with the spine nodes in remote sites when configuring Cisco ACI Multi-Site. The control plane TEP IP enables the spine nodes to exchange routing information and network reachability for seamless integration of multiple sites into a single ACI fabric. References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

The protocol used for exchanging MAC/IP address information for endpoints between spine switches in different pods within a Cisco Multi-Pod solution is MP-BGPEVPN (Multiprotocol BGP Ethernet VPN). This protocol facilitates scalable communication between separate locations by allowing MAC/IP address information sharing across pods. References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )

Configuring the Attachable Entity Profile (AEP) on a physical domain is necessary to ensure server ports can migrate to a different leaf switch in the event of a catastrophic failure. This configuration associates server ports with specific leaf switches and allows for seamless migration of connections without relying on Link Aggregation Control Protocol (LACP), which the server NICs do not support. References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )

 To establish intra-VRF communication between two EPGs deployed across different sites with different bridge domains, stretching the bridge domain and EPG components is necessary. Option D, “bridge domain,” and Option E, “EPG,” must be configured as stretched to facilitate communication across different sites within the same VRF. References:= Implementing Cisco Application Centric Infrastructure Official Cert Guide

The topology change notification (TCN) in Spanning Tree Protocol (STP) triggers a flush of the MAC address table. When a leaf node receives a TCN, it flushes the MAC address entries associated with the VLANs affected by the topology change. In this case, since the TCN is related to VLAN 101, the ACI fabric will flush all endpoints associated with VLAN 101 in bridge domain BD10123 on the leaf node.

 For a full mesh Cisco ACI Multi-Site architecture, configuring the BGP-EVPN Router-ID on each spine is essential. This configuration ensures unique identification and proper routing of traffic within the overlay network1

 In Cisco ACI, shared services like firewalls should be configured in the common tenant. This allows all tenants to access the services without duplicating them in each tenant.

When traffic to certain endpoints is dropped in a Cisco ACI fabric configured with hardware proxy, setting the L2 Unknown Unicast option to Flood for Layer 2 switched traffic can prevent this problem. This mode allows unknown unicast traffic to be flooded within the bridge domain, rather than being sent to the spine proxy and potentially discarded if the destination is unknown5.

References := Solved: Unknown Unicast in ACI Fabric - Cisco Community

 The output shows details of tunnel 6 within a Cisco ACI fabric. The transport protocol is listed as “isvlan,” which is typically associated with the GRE protocol in Cisco ACIterminology. GRE, a tunneling protocol developed by Cisco, encapsulates various network layer protocols inside virtual point-to-point links over an IP internetwork. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

 For the ISN implementation between Cisco ACI data centers using Multi-Site, OSPF must be configured on subinterfaces for dynamic routing, and BIDIR-PIM must be set up on all ISN routers for efficient bidirectional multicast traffic routing. References := (Implementing Cisco Application Centric Infrastructure Official Cert Guide)

To allow reachability to services outside of the Cisco ACI fabric while conserving TCAM resources, an engineer should use a contract insertion method where L30ut external EPGsact as providers and vzAny inside VRF acts as consumers. This configuration allows for communication from all EPGs within a VRF (represented by vzAny) to access external services through L30ut without having to create individual contracts for each service EPG, thus saving TCAM resources. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

 In Cisco ACI fabric, when a Layer 2 unknown unicast packet is encountered, the fabric does not drop the packet. Instead, it uses a flooding mechanism to ensure that the packet reaches its potential destination. This is achieved by utilizing the VRF (Virtual Routing and Forwarding) Outer Multicast Group ID associated with the Bridge Domain (BD) to which the unknown destination MAC address belongs. By doing so, Cisco ACI ensures that all endpoints within the BD have an opportunity to receive and process the packet if they are indeed the intended recipient. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

ARP flooding should be disabled on a bridge domain when the default gateway for endpoints is on an external device instead of a Cisco ACI bridge domain SVI. This is because ARP flooding allows for the resolution of IP addresses to MAC addresses within the bridge domain. When the default gateway is external, enabling ARP flooding can lead to unnecessary broadcast traffic on the network, as the ARP requests will not be contained within the ACI fabric. Disabling ARP flooding ensures that ARP requests are handled by the external device serving as the default gateway1234.

References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

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 In a stretched bridge domain solution between Cisco ACI sites with Layer 2 flood enabled, spine head-end replication is utilized to forward Broadcast, Unknown unicast, and Multicast (BUM) traffic between the sites. This method leverages the spine switches at each site to replicate BUM traffic to other sites, ensuring that all endpoints within the stretched bridge domain can receive such traffic. This approach is chosen over ISN multicast replication because it simplifies the overall design and reduces bandwidth consumption on inter-site links by avoiding unnecessary duplication of BUM traffic. References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )

In a Cisco ACI Multi-Site deployment, proper configuration of the inter-site link is crucial for traffic to pass between different sites. The MTU size is particularly important; if it’s not set correctly, packets may be dropped or fragmented, leading to connectivity issues. By configuring the MTU on the link to be at least 100 bytes larger than that of the ACI fabrics, you allow for encapsulation overhead without packet drops due to exceeding MTU limits. Additionally, configuring the link as a routed subinterface using VLAN-4 is necessary for routing across different broadcast domains, which is essential for inter-site communication in an ACI fabric. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

To redirect HTTP traffic between an EPG client and EPG server through a Cisco ASA firewall in a Cisco ACI environment, a contract filter must be configured to allow both ARP and HTTP. ARP is essential for IP to MAC address resolution, which is necessary for layer 2 communications within the same subnet or across subnets when routing is involved. The HTTP filter ensures that only HTTP traffic is redirected to the firewall for inspection or policy enforcement. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

 Deploying a new Cisco ACI Multi-Pod setup involves configuring the TEP pool of the new pod to be routable across the IPN (B) and increasing the interface MTU on all IPN routers to support VXLAN traffic (D). Configuring anycast RP (A) and MP-BGP on IPN routers © are not specific actions for deploying a Multi-Pod setup. Connecting all spines to the IPN (E) is not a required action for deployment3. References := (ACI Multi-Pod White Paper

 To set up the link between the spine and the IPN device in a Cisco ACI Multi-Pod, the following actions should be taken: A. Enable MP-BGP routing to facilitate the exchange of routing information. B. Enable BIDIR-PIM protocol to support efficient multicast traffic forwarding. D. Enable OSPF routing to ensure dynamic routing between the spine and IPN devices.

 In a Cisco ACI fabric, multicast traffic is managed using FTag trees that are rooted at the spine nodes. The Cisco APIC automatically determines the roots of these trees. This method optimizes the distribution of multicast traffic across the fabric by leveraging the spine nodes as centralized points for multicast routing and replication456.

References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

Implementing an active-active firewall cluster stretched across separate pods with anycast services configured offers several advantages, one of which is that it allows for optimized routing within the Cisco ACI fabric. When anycast services are used, each pod can have its own anycast node (firewall instance), and due to routing preferences set within ACI’s spine switches, they will prefer their local pod’s anycast node for routing decisions. This preference enhances efficiency by reducing cross-pod traffic and improving response times since local spines direct traffic to their respective local pod’s anycast nodes. References: Implementing Cisco Application Centric Infrastructure Official Cert Guide

 In a Cisco ACI Multi-Site setup, the source leaf is responsible for flooding BUM (Broadcast, Unicast, and Multicast) traffic to the specific multicast group or GIPo (Group IP Overlay). This process involves the ingress replication function on the spine nodes of the source site to replicate BUM traffic to all remote sites where the bridge domain is stretched12.

References := Cisco ACI Multi-Site Architecture White Paper, ACI Multi-Site Data Plane Communication - DCLessons

In an application-centric design, the creation of additional EPGs under one bridge domain is possible. This allows for greater flexibility in managing and segmenting network traffic for different applications or services within the same bridge domain.

References := Network Centric to ACI Centric Migration - Cisco

When a host connected to a Cisco ACI fabric leaf switch sends an ARP request, the ingress leaf switch uses a broadcast transmission method to send the ARP requests. This is because ARP requests are meant to discover the MAC address associated with a specific IP address within the same network broadcast domain. The ingress leaf switch does not know the destination MAC address, so it broadcasts the ARP request to all devices within the broadcast domain1.

References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )

To prevent MAC flapping on Cisco UCS Fabric Interconnects and ACI leaf switches, MAC Pinning should be selected for the VMM vSwitch Port Channel policy. This ensures consistent uplink usage for each virtual machine’s traffic, avoiding MAC address movement across multiple uplinks.

References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

When extending a Cisco ACI Multi-Pod setup to a Multi-Site implementation, configuring BIDIR-PIM in both the IPN (Inter-Pod Network) and ISN (Inter-Site Network) is necessary. This allows for efficient multicast traffic routing between multiple pods and sites.

References: = Implementing Cisco Application Centric Infrastructure Official Cert Guide

To support an application that is sensitive to latency and jitter, it is crucial to ensure that the Quality of Service (QoS) levels within the ACI fabric and the Inter-Pod Network (IPN) QoS policies are aligned. This alignment will help in maintaining consistent handling of the DSCP values set by the application (AF31 and CS6) as the packets traverse across the two ACI pods. By aligning the QoS levels and policies, the application’s packets are less likely to experience delays or drops, thus preserving the required performance levels for the application’s optimal functionality.

To implement the vPC (Virtual Port Channel) in the Cisco ACI fabric, one should select a common vPC interface policy group (Option A), select common interface profiles (Option C), and select common switch profiles (Option E). These steps ensure that both switches in a vPC domain are configured with consistent policies and profiles for interfaces and switches. This consistency is crucial for the proper functioning of a vPC setup where two or more links that are physically connected to two different Cisco ACI leaf switches appear as a single “logical” port channel to a third device, like the depicted WebServer.

LACP is the correct mode for the port-channel policy to ensure failover and full bandwidth utilization in both directions when integrating a Cisco ACI fabric with VMware using a VPC connected to Leaf1 and Leaf2. It allows multiple physical ports to be bundled into a single logical channel, providing redundancy and increased bandwidth. References := (Implementing Cisco Application Centric Infrastructure Official Cert Guide)

 To meet the requirements specified, two actions must be taken: B. Create a standard contract between EPG 51 and EPG 10 to explicitly allow communication between these two EPGs. A contract in Cisco ACI defines the communication policy between EPGs, and by creating a standard contract, specific communication can be permitted. E. Enable the Preferred Group option on EPGs 1 to 50 to allow communication within this group of EPGs. The Preferred Group feature in ACI allows all EPGs within the group to communicate with each other without the need for explicit contracts, while still enforcing contracts for communication with EPGs outside the group. References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

To facilitate communication between EPG1 in VRF1 and External EPG in VRF2, the following actions are necessary:

Enable Shared Route Control Subnet: This allows subnets to be shared across different VRFs, which is essential for inter-VRF communication.

Enable External Subnets for External EPG: Activating this makes the subnets within the External EPG routable to external networks.

Enable Import Route Control Subnet: This enables the importation of routes from L3Out into the VRF, permitting connectivity between different VRFs.

These steps ensure that routing and security policies are correctly implemented to permit traffic flow between EPG1 and External EPG across distinct VRFs.

References: Implementing Cisco Application Centric Infrastructure Official Cert Guide