SD-WAN-Engineer Exam Preparation Material | Palo Alto Networks SD-WAN Engineer

Explanation:
Comprehensive and Detailed Explanation
According to the Prisma SD-WAN Performance Policy Default Behavior documentation, the default action configured for applications (including real-time media) when a path experiences poor performance (violates the SLA thresholds for latency, jitter, or packet loss) is to Move Flows.
The Prisma SD-WAN ION device continuously monitors the health of all available paths. If the active path for a media application degrades and fails to meet the specified SLA, the default policy dictates that the traffic should be steered (moved) to an alternate, compliant path that meets the performance criteria.
While Forward Error Correction (FEC) is a powerful feature available in Prisma SD-WAN to mitigate packet loss for real-time applications, it is an optional action that must be explicitly enabled or configured within the performance policy rules. It is not the default action in the base system configuration; the primary default mechanism for handling performance issues is to leverage the multi-path fabric to switch to a better link.
Reference: Prisma SD-WAN Administrator's Guide: Performance Policy Default Behavior

Explanation:
Prisma SD-WAN licensing is structured to provide flexibility while ensuring that all components of the secure fabric are correctly accounted for. To meet the requirements of this organization, we must calculate the necessary subscriptions for both the data center hubs and the distributed branch network.
First, we address the Data Center Subscriptions. The organization has two main geographically separate data centers and one small data center, all of which require High Availability (HA). In a Prisma SD-WAN deployment, HA at a site is achieved by deploying two ION devices in a cluster. Palo Alto Networks licensing requires a separate Data Center subscription for each ION device acting as a hub. Therefore, with three data center locations (2 main + 1 small) each requiring an HA pair (2 devices per site), a total of six data center subscriptions (Option A) are required to license all six hub appliances.
Second, we address the Branch Subscriptions. The organization has 50 branches but lacks accurate measurements of actual bandwidth consumption. Palo Alto Networks' best practice for such scenarios is the Aggregate Bandwidth Subscription model (Option B). Instead of purchasing a fixed "Branch subscription per site" (Option D)―which requires knowing the exact throughput needs for every individual location―the aggregate model allows the customer to purchase a total pool of bandwidth (e.g., 5 Gbps) that is shared across all 50 branch sites.
This "pay-as-you-grow" approach is ideal when consumption patterns are unknown or inconsistent. As branches utilize the bandwidth, it is deducted from the central pool. This avoids the risk of over-provisioning licenses at low-usage sites or under-provisioning at high-usage sites. Together, the six DC subscriptions and the aggregate bandwidth pool provide a fully licensed, HA-capable SD-WAN environment that aligns with Palo Alto Networks' scaling recommendations.

Explanation:
In the Prisma SD-WAN architecture, reachability between sites is managed by the Control Plane, which automatically advertises prefixes across the secure fabric based on their scope. If a branch site has successful Direct Internet Access (DIA) but is invisible to the Data Center (DC), it indicates that while the local ION is online, its internal network information has not been propagated to the rest of the SD-WAN fabric.
The most common cause for this behavior is that the LAN interfaces or static routes at the branch are configured with a Local scope rather than a Global scope. When a prefix is set to "Local," the ION device treats that network as reachable only within that specific site; it will not advertise that prefix to the Controller for distribution to other ION devices, such as those at the Data Center. By ensuring the LAN branch prefixes are set to "global" (Option B), the administrator instructs the ION device to share these routes with the global fabric.
Once the prefix is marked as global, the Prisma SD-WAN Controller identifies it as a reachable destination and updates the routing tables of all peer ION devices in the same domain, including the DC gateways. This allows the Data Center to build a valid path to the branch resources over the secure VPN tunnels.
Options like creating static routes (Option A) or changing site modes (Option C) do not address the fundamental requirement of prefix advertisement within the software-defined fabric, which relies on correctly defined metadata like route scope.

Explanation:
Comprehensive and Detailed Explanation
In Prisma SD-WAN, security policies can be applied via Policy Stacks, which often have a hierarchy.
Stack Precedence: A common configuration involves a Global Security Stack (applied to all sites) and a Local/Site Security Stack (specific to one site). If the administrator configured a "Global" rule that says "Deny Access to Gambling Sites" (or a specific IP list), and that rule is higher in the binding order or part of a higher-priority stack, it will enforce the block before the local "Allow Guest to Internet" rule is processed.
Specifics of "REJECT": The state REJECT specifically implies a policy enforcement action (sending a TCP RST or ICMP Unreachable) rather than a silent drop or a routing failure.
Why not A? If the "Allow" rule is at the top and matches the traffic parameters (Zone/IP), the Default Deny at the bottom would never be reached. The issue implies a higher priority Deny exists.

Explanation:
Comprehensive and Detailed Explanation
Site Templates (often referred to as Site Configuration Templates) are a critical tool for the Zero Touch Provisioning (ZTP) of large-scale deployments in Prisma SD-WAN.