SD-WAN-Engineer Exam Dumps - Palo Alto Networks SD-WAN Engineer

In complex retail or banking environments, maintaining strict network segmentation is a regulatory and security requirement. Prisma SD-WAN utilizes Virtual Routing and Forwarding (VRF) to provide this isolation, ensuring that high-security traffic, such as ATM transactions or teller cash registers, remains logically separated from Guest Wi-Fi or general corporate applications. While isolation is the default state, route leaking is used to allow specific communication between these VRFs—for instance, allowing multiple isolated segments to reach a common shared service like a DNS server or a centralized security gateway.

To verify that these configurations have been correctly pushed from the Controller to the local ION device, administrators utilize the ION CLI (Command Line Interface) for deep-dive diagnostics. The command inspect vrf route_leak_rule all is the definitive tool for this purpose. Unlike "show" commands which typically provide interface status, "inspect" commands in the Prisma SD-WAN ecosystem are designed to pull real-time operational state data from the control plane's internal databases.

When executed, this command displays the specific prefix-level rules that allow routes to "leak" from one VRF table into another. It provides visibility into the source VRF, the destination VRF, and the exact network prefixes or default routes being shared. This is critical for troubleshooting "Day 2" operations; if a teller register cannot reach a shared database, the administrator can use this command to confirm if the necessary route leak rule is active and accurately reflecting the intent of the VRF Profile configured in the portal. Without this command, verifying inter-VRF reachability would be limited to trial-and-error connectivity tests, making it an essential part of the Prisma SD-WAN engineer's toolkit.

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.

1. Device Pre-staging (Statement C):

One of the primary capabilities of Site Templates is the creation of Device Shells. A device shell is a configuration container that exists in the controller before the physical hardware is installed or connected. By using a template, an administrator can pre-provision the entire configuration (interfaces, routing, subnets) for the "Site" and "Element" (Device). When the physical ION device is later connected to the internet and claimed (associated with the shell via its Serial Number), it immediately inherits this pre-staged configuration, enabling a true "plug-and-play" deployment.

2. Mandatory Variables (Statement B):

To successfully instantiate a functional site from a generic template, specific unique identifiers are required in the variable data set (typically a CSV file).

Site Name: Identifies the location in the portal.

ION Software Version: Ensures the device boots to the specific validated code version required for the deployment, preventing inconsistencies.

ION Serial Number / Device Name: Required to bind the logical configuration (Shell) to the physical hardware. Even if the serial is added later during the claim process, the structure of the template and the deployment workflow mandates these variables to ensure the device can be uniquely identified and managed within the fabric.

Note on Option D: While it is technically possible to re-deploy a template, the Best Practice for "Day 2" operations (updating or modifying configuration after deployment) is to use Prisma SD-WAN Stacks (Network Stacks, Security Stacks, etc.). Stacks allow for granular, policy-based updates across multiple sites without the destructive or rigid nature of re-applying a full site initialization template. Therefore, D is not the aligned best practice.

Comprehensive and Detailed Explanation

In a Prisma SD-WAN Data Center deployment, the operational state of the Secure Fabric VPNs (overlay tunnels) is directly tied to the health of the BGP Core Peer configuration.4

Core Peer Dependency: DC ION devices typically peer with the data center core switch (Core Router) via BGP to learn the subnets (prefixes) for the applications hosted in the DC. The Prisma SD-WAN controller monitors this BGP peering status.5

Controller Logic: If the BGP Core Peer on a DC ION goes down (or is not established), the controller automatically marks the VPN tunnels terminating at that specific ION as "Inactive".6 This is a fail-safe mechanism designed to prevent remote branches from sending traffic to a DC ION that has lost conne7ctivity to the internal data center network (and thus the applications).

Scenario Analysis: In this scenario, DC ION-1 has active VPNs, meaning its BGP Core Peer is UP and it is successfully advertising reachability. DC ION-2 has no active VPNs, which strongly indicates that its BGP Core Peer is down.8 Because the controller sees the peer is down, it suppresses the tunnel establishment or marks existing tunnels as inactive to ensure traffic is only directed to the healthy node (ION-1).

Comprehensive and Detailed Explanation

The best practice for managing upgrades in a large-scale Prisma SD-WAN environment is the Canary or Phased Rollout approach, utilizing Site Tags.

Risk Mitigation: Upgrading all sites simultaneously (Option B) is highly risky. If the new software version has an unforeseen bug or compatibility issue with a specific circuit type, the entire network could face an outage.

Tag-Based Management: Administrators should create tags such as "Upgrade-Phase-1" (Pilot sites) or "Region-North". By assigning the specific Software Version to the Tag (rather than the individual site or the global default), the controller pushes the update only to that subset of devices.

Procedure:

Apply update to "Pilot" tag (5 sites). Monitor for 24-48 hours.

Apply update to "Region-1" tag (50 sites). Monitor.

Eventually, update the Global default once confidence is high.

Option A is unscalable, and Option D is incorrect as the administrator retains full control over when upgrades occur; they are not forced automatically without policy configuration.

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.