Cisco 300-630 Exam Dumps & Practice Test Questions

Question No 1:

A cloud service provider needs to deploy two firewalls that will be accessible by all tenants, while allowing each tenant to independently design their own service graph. 

Where should these Layer 4 to Layer 7 network services be placed to support this setup?

A Management tenant
B Infrastructure tenant
C User tenant
D Common tenant

Answer: B

Explanation:

In multi-tenant cloud environments, it is important to properly design how network services like firewalls, load balancers, and other Layer 4 to Layer 7 components are shared among tenants. The key consideration here is making the firewalls available to all tenants, without forcing each one to implement and manage their own instance. This promotes centralization and consistency in security enforcement while also reducing management overhead.

The infrastructure tenant is designed specifically to host shared services that need to be used by multiple tenants. These services include firewalls, service devices, and policy enforcement engines that support various application connectivity needs across the cloud environment. By configuring the firewalls in the infrastructure tenant, the cloud provider ensures that the services are globally available to all user tenants. Each tenant can still define their own service graph to determine how their traffic flows through these shared services, giving them control over their network architecture without duplicating firewall instances.

The management tenant, while essential for monitoring and administrative control, is not the right place to deploy shared Layer 4 to Layer 7 services. Its primary role is orchestration, logging, auditing, and overall system health monitoring.

The user tenant is dedicated to customer-specific applications and services. Each tenant has autonomy to design and manage their own workloads, but this tenant is not meant to host shared infrastructure elements. Placing firewalls here would restrict their usage to a single tenant and contradict the requirement of accessibility to all tenants.

The common tenant often refers to a pool of shared resources or templates, but it is generally not designated for critical network services that require centralized management and high availability. It might be used for images, configurations, or shared templates but not for shared firewalls.

Therefore, configuring the firewalls under the infrastructure tenant ensures that all user tenants can access them while maintaining independence in defining service paths. This approach promotes scalability, simplifies maintenance, and supports a modular service graph design for each tenant. It also helps enforce consistent security policies across the cloud environment, without compromising the autonomy of individual users.

Question No 2:

In a Cisco ACI setup, if endpoint devices use an external router instead of the bridge domain’s SVI as their default gateway, which configuration setting must be turned off to avoid network communication problems?

A Unicast Routing
B ARP Flooding
C Unknown Unicast Flooding
D Proxy ARP

Answer: D

Explanation:

In Cisco ACI, the bridge domain represents a Layer 2 domain where endpoints are grouped. Normally, the fabric assigns a switched virtual interface (SVI) to the bridge domain, which acts as the default gateway for all connected devices. When the SVI serves as the gateway, features like Proxy ARP and Unicast Routing allow the fabric to respond to routing requests and handle IP communication effectively.

However, when an external router is used as the default gateway instead of the bridge domain's SVI, special consideration is required for how ARP requests are handled. Proxy ARP is a feature that allows a device to respond to ARP requests on behalf of another. In this case, if Proxy ARP remains enabled in the bridge domain, ACI may try to answer ARP requests for IP addresses that are not directly reachable through the fabric. This results in incorrect ARP replies and causes packets to be misrouted or dropped, disrupting communication between endpoints and external networks.

Disabling Proxy ARP ensures that the ACI fabric does not respond to ARP queries on behalf of the external router. Instead, ARP requests for the default gateway IP address will be forwarded to the actual gateway device, which is located outside the ACI fabric. This adjustment prevents incorrect assumptions by ACI and ensures that all routing and ARP behavior is accurate and consistent with the external routing topology.

Looking at the other options:

A Unicast Routing refers to enabling Layer 3 routing within the fabric. While related to overall routing behavior, it does not directly cause issues with ARP when an external gateway is used.

B ARP Flooding causes ARP requests to be broadcast to all endpoints in the bridge domain. While it could theoretically assist in ARP discovery, it does not resolve the issue caused by Proxy ARP interfering with correct ARP replies.

C Unknown Unicast Flooding enables the forwarding of unknown unicast traffic to all bridge domain ports. This is unrelated to the handling of ARP requests and would not prevent incorrect gateway responses.

For proper operation when an external router is used as the default gateway, Proxy ARP must be turned off to avoid miscommunication and ensure the external gateway handles its own ARP responses as intended.

Question No 3:

An engineer is managing a Cisco ACI environment where different departments are set up as separate tenants. To simplify policy administration, a shared contract is being used by all tenants. However, strict security rules mandate that these tenants should not be able to communicate with one another, even though they are using the same shared contract. 

What is the proper configuration to ensure that this shared contract can be reused without enabling communication between tenants?

A Create the contract in the user tenant with the scope set to VRF and export it to other tenants
B Create the contract in the common tenant with the scope set to Tenant
C Create the contract in the user tenant with the scope set to Global and export it to other tenants
D Create the contract in the common tenant with the scope set to Global

Answer: B

Explanation:

In Cisco ACI, contracts are used to define the rules for traffic allowed between endpoint groups, or EPGs. When dealing with multiple tenants in an ACI environment, there is often a need to share contracts so policies can be uniformly applied across different parts of the network. The scope of a contract determines how far and to whom that contract can apply. The scope options include VRF, Tenant, and Global.

A contract with VRF scope can only enforce communication between EPGs that exist within the same Virtual Routing and Forwarding instance. When the scope is set to Tenant, the contract applies within that tenant only and cannot affect traffic in other tenants. When the scope is set to Global, it allows the contract to be used across multiple tenants and VRFs, enabling inter-tenant communication.

In this scenario, security requirements strictly prohibit inter-tenant communication. Although the contract should be reusable for ease of management, it should not enable any cross-tenant interaction. The ideal solution is to place the contract in the common tenant. This is a special tenant in Cisco ACI that acts as a central repository for shared resources. Creating a contract here allows it to be referenced by other tenants.

However, setting the contract’s scope to Global would contradict the security mandate, as this would permit cross-tenant traffic. Setting the scope to Tenant within the common tenant provides the needed balance: tenants can reference the shared contract, but enforcement remains isolated to within the tenant that’s using it. This configuration prevents inter-tenant communication, satisfying the security policy.

Creating the contract in a user tenant and exporting it (as described in options A and C) is not recommended for shared use across tenants, especially under strict isolation rules. Global scope (as in option D) should also be avoided when strict segmentation is needed.

So the best and most secure approach is to use the common tenant and set the contract scope to Tenant, ensuring reuse without compromising isolation.

Question No 4:

A business is rolling out a critical application that is highly sensitive to both latency and jitter. This application will operate across two pods in a Cisco ACI multi-pod fabric. The application uses DSCP values AF31 and CS6 in its packet headers to indicate traffic priority levels. The customer is worried that inconsistent handling of these marked packets as they pass through the Inter-Pod Network (IPN) may cause performance problems. 

What configuration should be used to ensure these packets are treated properly throughout their journey?

A Disable DSCP translation policy
B Align the ACI QoS levels and IPN QoS policies
C Disable DSCP mapping on the IPN devices
D Align the custom QoS policy on the EPG site in the customer tenant

Answer: B

Explanation:

When deploying a latency-sensitive application in a Cisco ACI environment, particularly in a multi-pod setup, it is essential to ensure that Quality of Service (QoS) policies are consistent across all infrastructure involved in the data path. The application in this case uses DSCP markings—AF31 and CS6—to indicate the importance and priority of its packets. These markings are recognized by network devices to apply appropriate traffic treatment such as queuing, scheduling, or prioritization.

Inside a Cisco ACI fabric, DSCP values are internally translated into ACI’s own QoS levels. For instance, ACI defines three main levels: Level 1 (Best Effort), Level 2 (Assured Forwarding), and Level 3 (Priority). When a packet marked with AF31 or CS6 enters the ACI fabric, the fabric maps it to the corresponding internal QoS level. However, this translation only ensures proper handling within the ACI-controlled segments.

The IPN, which connects multiple pods in a multi-pod ACI deployment, lies outside the ACI fabric. If the QoS configuration on the IPN devices does not align with ACI’s internal mapping, packets may suffer from delays or loss due to mismatched treatment. For instance, a high-priority CS6-marked packet might get treated as low priority if IPN policies don't recognize or preserve the intended QoS level.

Option B is the correct configuration because aligning ACI’s QoS settings with those on the IPN ensures that packets maintain their priority across the entire path. This avoids reclassification, downgrading, or mismanagement of traffic as it transitions between ACI and non-ACI segments.

Option A suggests disabling DSCP translation, which could strip away important packet markings and reduce the effectiveness of QoS policies. Option C would also prevent correct prioritization if the IPN cannot interpret or honor DSCP values. Option D focuses only on tenant-level policy, which doesn’t address the broader challenge of inter-pod communication.

Therefore, for consistent end-to-end handling of high-priority application traffic across ACI and the IPN, aligning the QoS policies of both infrastructures is essential. This approach ensures that packet priority is preserved, and performance is maintained across the full communication path.

Question No 5:

In a Cisco ACI environment, two border leaf switches have been set up with an L3Out using OSPF to provide shared external Layer 3 services for multiple tenants. The goal is to make sure that the external routes received by these border leaf switches are available to compute leaf switches across the fabric. 

What configuration step must be taken to ensure that these OSPF-learned routes are visible to all necessary switches and tenants?

A Configure a BGP route reflector policy for the Cisco ACI pod
B Define the shared L3Out in the common tenant
C Enable Import Route Control Enforcement in the L3Out policy
D Define the consumer subnet under the consumer EPG

Answer: B

Explanation

In Cisco ACI, L3Outs are used to connect the fabric to external networks through routing protocols like OSPF or BGP. The tenant in which the L3Out is created determines which parts of the fabric can access the learned routes. When an L3Out is defined under a specific tenant, only that tenant can use the routes unless you configure route leaking. However, when the goal is to share these routes across multiple tenants, the correct design pattern is to place the L3Out in the common tenant.

The common tenant in Cisco ACI is designed to hold shared policies, services, and configurations. Defining the L3Out in this tenant enables routes learned from outside the fabric to be distributed to other tenants using contracts and route leaking. This setup ensures that workloads across different tenants can access external networks through the shared L3Out, satisfying the requirement that the routes be visible throughout the fabric.

Option A is incorrect because BGP route reflectors are used when BGP is the protocol of choice, but in this case, the L3Out is using OSPF, so this has no relevance.

Option C involves controlling which imported routes are accepted, but it does not by itself enable the sharing of those routes across tenants. It is useful for filtering, not distribution.

Option D refers to defining a consumer subnet under an EPG, which relates more to endpoint access and contract policies. It does not impact the route advertisement and distribution process from L3Outs to the rest of the fabric.

Therefore, placing the L3Out in the common tenant is the correct step because it allows external routes learned via OSPF to be shared and accessed across different tenants and compute leaf switches. This enables full routing functionality as expected in a multi-tenant fabric design.

Question No 6:

A network engineer needs to redistribute routes between two L3Outs in a Cisco ACI fabric. All relevant routes fall within the 10.16.0.0/16 range, and the engineer wants to advertise these from one L3Out to the other without listing individual routes. 

What configuration should be applied to the External EPG to meet this requirement?

A Enable Export Route Control Subnet and enable Aggregate Export
B Disable Shared Route Control Subnet and enable Aggregate Shared Routes
C Enable Export Route Control Subnet and disable Aggregate Shared Routes
D Enable Export Route Control Subnet and enable Shared Route Control Subnet

Answer: A

Explanation

Cisco ACI uses External EPGs to manage how routes are imported and exported through L3Outs. When redistributing routes from one L3Out to another, it is necessary to define which routes are allowed to be advertised using route control subnets. The Export Route Control Subnet setting enables a subnet to be advertised out of the ACI fabric or between L3Outs.

Since the engineer does not have a list of all individual routes and instead wants to advertise all routes within the 10.16.0.0/16 range, route summarization becomes important. Enabling the Aggregate Export option allows ACI to treat the entire block as a single summarized route. This reduces the number of routes advertised and improves scalability and efficiency, especially in large environments.

Option A correctly includes both enabling export control and enabling route aggregation. This combination ensures that any subnets within 10.16.0.0/16 are advertised from one L3Out to another without needing to list each one.

Option B is incorrect because it disables the Shared Route Control Subnet and applies aggregation to shared routes, which is unrelated to the export goal. This setup is more applicable when sharing routes between tenants rather than between L3Outs.

Option C includes enabling export but disables the shared route aggregation, which again does not meet the full requirement. The aggregation is critical when no individual route list is provided.

Option D enables both export and shared route control but lacks the aggregation feature, which is necessary to advertise the entire CIDR block as a summarized route.

To summarize, exporting the entire 10.16.0.0/16 block from one L3Out to another in an efficient and scalable way requires both export control and route aggregation. Option A is the only one that satisfies both these conditions.

Question No 7:

A company has expanded its Cisco ACI Multi-Pod network from two pods to six pods in order to increase scalability and geographic coverage. To ensure control plane performance and efficient handling of Broadcast, Unknown Unicast, and Multicast (BUM) traffic across the Inter-Pod Network (IPN), the networking team must select the most suitable technology for the task.

A. Spine Headend Replication
B. BIDIR-PIM
C. MP-BGP
D. MSDP

Answer: B

Explanation

In a Cisco ACI Multi-Pod deployment, each pod operates as a separate fabric interconnected through the Inter-Pod Network, or IPN. As more pods are added—moving from two to six in this case—the replication and distribution of BUM traffic becomes increasingly complex and resource-intensive if not handled properly. Efficiently managing this kind of traffic across geographically separated locations requires a solution that minimizes overhead and control plane complexity.

Bidirectional Protocol Independent Multicast, or BIDIR-PIM, is specifically designed for efficient multicast forwarding in many-to-many communication scenarios, which fits the requirements of a Multi-Pod ACI architecture. BIDIR-PIM simplifies multicast operation by using a shared tree and removing the need for source registration and multiple Rendezvous Points. This shared tree enables all pods to replicate multicast and BUM traffic efficiently without creating individual source trees per pod. As a result, BIDIR-PIM significantly reduces control plane load and scales well across multiple pods.

Spine Headend Replication, represented by option A, is appropriate only within a single ACI fabric. It is used to replicate BUM traffic from spines to leaves internally, not across the IPN. It doesn’t scale well across pods and therefore is not recommended in a Multi-Pod deployment.

MP-BGP, shown in option C, serves as the protocol for exchanging control plane information between pods. While essential for route distribution and endpoint reachability, MP-BGP does not deal with BUM traffic replication, so it cannot be used as a solution to this specific problem.

Option D, MSDP, is used in inter-domain multicast scenarios, particularly in sparse-mode multicast environments to share source information between separate multicast domains. However, it is not designed for or supported in Cisco ACI Multi-Pod environments due to complexity and limited scalability.

Given the increasing scale of the deployment and the need for efficient BUM traffic handling, BIDIR-PIM is the most appropriate and scalable solution. It supports multicast replication across multiple pods using a shared tree, reducing control plane complexity and optimizing overall network performance in a Multi-Pod architecture.

Question No 8:

A network engineer is deploying firewalls in an active-standby configuration across two pods in a Cisco ACI Multi-Pod design. Each firewall is located in a different pod. The goal is to ensure uninterrupted external access even if one firewall fails, while also supporting efficient routing and failover mechanisms. 

What is the best method to deploy the firewalls within this Multi-Pod architecture?

A. Policy-Based Redirect (PBR) for routed firewalls
B. Separate Layer 3 Out (L3Out) configurations for each routed firewall
C. Routed firewall acting as the default gateway for all external traffic
D. Transparent (bridge mode) firewalls for external routing

Answer: B

Explanation

In a Cisco ACI Multi-Pod environment, firewalls are often deployed for securing external connectivity, and in many cases, they operate in an active-standby mode to ensure high availability. When these firewalls are physically located in different pods, the architecture must be carefully designed to provide seamless failover and continuous connectivity. The most suitable and scalable solution in this case is to configure separate Layer 3 Out (L3Out) connections for each firewall, with one L3Out per pod.

By creating individual L3Out connections for each firewall, ACI allows each pod to learn external routes independently through its local firewall. When the active firewall is operational, it advertises the necessary routes to the fabric through its L3Out. If the active firewall fails, the standby firewall in the other pod takes over, and its own L3Out begins to advertise the same routes, ensuring uninterrupted service. This approach is particularly effective because it supports route convergence and minimizes dependency on a single point of failure.

Option A, Policy-Based Redirect, is used primarily within service graphs to steer traffic to specific services such as firewalls or load balancers within the same pod. It is not designed to provide high availability across multiple pods and does not address the need for external failover.

Option C, using a single routed firewall as the default gateway, creates a single point of dependency. It also centralizes all external traffic through one location, which can introduce suboptimal routing and potential scalability issues in a Multi-Pod architecture.

Option D, deploying firewalls in transparent mode, limits routing capabilities. Transparent firewalls do not participate in dynamic routing, making it difficult to adapt to changes in topology or failover situations. This setup lacks the flexibility needed in a distributed Multi-Pod design.

In contrast, using separate L3Outs in each pod enables distributed control, efficient route propagation, and failover support. It adheres to Cisco best practices for ACI Multi-Pod design and ensures external connectivity remains intact regardless of which firewall is active. Therefore, the correct and recommended choice is to configure separate L3Outs for each routed firewall.

Question No 9:

Which of the following components is typically responsible for network segmentation in a Cisco ACI environment?

A. Virtual Port Channel
B. Bridge Domain
C. Application Profile
D. Tenant

Explanation:

In a Cisco ACI (Application Centric Infrastructure) environment, the Tenant plays a crucial role in network segmentation. A Tenant provides the highest level of isolation within ACI by allowing different virtual network structures to be created for distinct groups or departments within an organization. This level of segmentation helps in ensuring that the policies and configurations defined for one tenant do not affect others. The Tenant houses Application Profiles, which contain EPGs (End-Point Groups) that define specific application workloads and their relationships. While Bridge Domains provide Layer 2 connectivity for EPGs, it is the Tenant that ensures complete logical separation of resources and policies, making it fundamental to network segmentation in ACI.

On the other hand, Virtual Port Channels (VPC) and Application Profiles focus on link aggregation and application-specific configurations, respectively, but they are not responsible for network segmentation directly. Bridge Domains are related to Layer 2 segmentation but are typically configured within a Tenant and cannot function as isolated segments on their own without the Tenant structure.

Question No 10:

What is the role of the APIC controller in a Cisco ACI fabric?

A. It operates as a hardware switch for traffic forwarding.
B. It serves as the centralized management point for the fabric.
C. It is used exclusively for configuring Layer 3 routing protocols.
D. It handles data encryption between devices within the fabric.

Explanation:

The APIC (Application Policy Infrastructure Controller) serves as the brain of the Cisco ACI (Application Centric Infrastructure) fabric, providing centralized management and policy enforcement across the entire network. The APIC manages the Cisco ACI fabric, automating network provisioning, policy definition, and monitoring for the environment. It controls both the data and control planes of the network, ensuring that all devices within the fabric adhere to the configured policies and providing a unified view of the network for administrators.

While APIC does not directly participate in traffic forwarding (this role is typically handled by the Leaf and Spine switches), it plays a vital role in managing the overall configuration, including network automation, security, and quality of service (QoS) policies. The APIC is also responsible for enforcing application-centric policies, which include both virtual and physical networking. It does not specialize in Layer 3 routing or data encryption directly; those tasks are handled by other components in the network, such as the routers or security devices, depending on the deployment.