SD-WAN-Engineer Exam Dumps - Paloalto Networks Network Security Administrator Questions and Answers

Comprehensive and Detailed Explanation

In Prisma SD-WAN,Custom Applicationsare global policy objects managed centrally on the controller.

Immediate Propagation:When an administrator creates or modifies a Custom Application definition (e.g., updating the IP subnet or port for an internal app), the Prisma SD-WAN controller automatically pushes this update toallconnected ION devices in the tenant.

No Manual Push:Unlike some legacy firewall management paradigms (like Panorama "Commit and Push"), the Prisma SD-WAN architecture is "intent-based" and continuously synchronized. A change to a global object like an App Definition is considered a live configuration change and is distributed immediately via the secure control channel.

No Reboot:The ION data plane updates its classification engine dynamically without interrupting traffic or requiring a reboot. This ensures that policy enforcement (steering "Inventory_App" to the correct path) remains accurate in real-time.

Comprehensive and Detailed Explanation

In the Prisma SD-WAN Flow Browser, theFlow Stateprovides a real-time snapshot of the TCP/UDP session lifecycle.

INIT (Initialization):This state indicates that the ION device has seen the initial packet of a new session (typically a TCP SYN) originating from the client (Source), but it hasnot yet seen a return packet(such as a TCP SYN-ACK) from the destination server.

Diagnosis:A flow stuck in INIT is a classic indicator of a "Blackhole" or reachability issue downstream. It implies that the ION successfully routed the packet out toward the destination, but the destination did not reply. Common causes include:

The server is offline.

A firewall in the path (or on the server itself) is dropping the traffic.

Routing is broken on the return path (asymmetric routing where the return traffic bypasses the ION).

If the flow had been denied by the ION's own firewall (Option C), the state would typically show as DENY or REJECT. If the handshake completed (Option A), the state would be ESTABLISHED. Therefore, INIT points to a lack of response from the remote end.

Comprehensive and Detailed Explanation

TheCloudBladeplatform is a distinguishing architectural component of the Prisma SD-WAN solution. It isnota physical piece of hardware, nor is it software that runs directly on the branch ION device's CPU.

Instead, the CloudBlade platform is acloud-based API integration layerhosted by Palo Alto Networks. It functions as an intelligent broker or "translator" between the Prisma SD-WAN Controller and external third-party services (such as Prisma Access, Amazon Web Services, Azure, ServiceNow, or Zscaler).

When an administrator configures thePrisma Access CloudBlade, for example, they input their API credentials and intent (e.g., "Connect all US branches to US West"). The CloudBlade engine then:

Communicates with the Prisma Access API to provision the remote IPSec termination nodes (Security Processing Nodes).

Translates this configuration into specific instruction sets for the Prisma SD-WAN Controller.

The Controller then pushes the necessary VPN tunnel configurations, IKE parameters, and routing rules to the relevant ION devices.

This architecture eliminates the need for manual IPSec configuration on every branch device. It ensures that if the third-party service changes its IP addresses or settings, the CloudBlade can detect the change via API and automatically update the branch fleet, maintaining connectivity without manual administrator intervention.

Comprehensive and Detailed Explanation

The transition from "Claimed" to "Online" depends entirely on the ION device's ability to establish a secure, persistent management tunnel to the Prisma SD-WAN Controller.

Connectivity Requirements:The ION device initiates an outbound connection to the controller onTCP Port 443 (HTTPS). It also requires accurate time synchronization to validate SSL certificates, necessitating access toNTP (UDP Port 123).

Scenario Analysis:Since the installer can browse the internet from the LAN, we know the physical link and basic routing/NAT are functional. The issue is specific to themanagement planetraffic.

Root Cause:If an upstream firewall (e.g., a corporate edge firewall or ISP filter) is inspecting SSL traffic or blocking specific FQDNs/Ports required by the ION, the device cannot complete the handshake. Consequently, it remains "Claimed" (registered in the database) but cannot go "Online" (active management session). Options A, C, and D preventprovisioning(configuration push) but generally do not prevent the device from initially checking in and going "Online" if the pipe is open.

Comprehensive and Detailed Explanation

For a successful Zero Touch Provisioning (ZTP) experience, the ION device must be able to obtain an IP address and reach the internet immediately upon boot-up.

According to Palo Alto Networks hardware guides, the Controller Port (often labeled specifically as "CONTROLLER" on models like the ION 3000/7000/9000) is pre-configured to act as a DHCP client by default. It is the preferred interface for the initial "call home" process.

However, for smaller desktop models (like the ION 1000/2000/1200 series) or scenarios where a dedicated management network is not available, the device firmware is also configured to attempt DHCP client requests on Port 1 (often labeled as Internet 1 or simply 1).

Connecting the ISP circuit to any random port (like Port 4 or a LAN port) will not work for ZTP because those interfaces are not pre-configured as DHCP clients in the factory default state. Therefore, the installer must ensure the internet uplink is connected to either the dedicated Controller port or Port 1/Internet 1 to ensure the device can resolve the controller FQDN and download its configuration.

Comprehensive and Detailed Explanation

Prisma Access managesRemote Networkbandwidth using anAggregate Bandwidthlicensing model.

Compute Locations:When you purchase bandwidth (e.g., 1 Gbps), you allocate it to specific Prisma AccessCompute Locations(e.g., US West, Europe Central).

Shared Pool:All branch sites (Remote Networks) that connect to that specific Compute Location share the allocated bandwidth pool. For example, if you allocate 500 Mbps to "US West" and connect 10 branches to it, they compete for that 500 Mbps aggregate.

Bursting:An individual branch isnotstrictly rate-limited to a "slice" (e.g., 50 Mbps) unless you explicitly configure QoS guarantees. By default, a single branch can burst and consume a large portion of the aggregate pool if other branches are idle. The enforcement happens at the Region/Compute Node level, ensuring the total throughput does not exceed the licensed capacity for that region.

Comprehensive and Detailed Explanation

TheION Device Data Plane(the software running locally on the hardware appliance at the branch) is the component responsible for the heavy lifting of traffic analysis.

Edge Processing:Prisma SD-WAN uses an "Application-Defined" architecture. The ION device performsDeep Packet Inspection (DPI)on the first few packets of a flow to identify the application (e.g., distinguishing "Skype Video" from "Skype Chat").

Metric Calculation:The ION device timestamping engine calculates the performance metrics (RTT, NTT, SRT) in real-time as packets pass through its interfaces. It aggregates this metadata.

Role of Controller (B):The Controllercollectsandvisualizesthis data (Analytics), but it does notgenerateit. The Controller does not sit in the data path of the user traffic. If the ION relied on the controller for App-ID, latency would be unacceptably high. Therefore, all detection and metric generation happens locally on theION Device.

Comprehensive and Detailed Explanation

In the Prisma Access architecture (integrated with SD-WAN), distinct connection types serve different purposes.

Remote Networks:These are the connections from yourBranchsites (using ION devices) into the cloud. They allow branches to get to the internet or other branches.

Service Connections (SC):This is a specialized high-bandwidth connection used to bridge thePrisma Access Cloudto yourPrivate Data Centeror Headquarters.

The primary use case for a Service Connection (Option A) is to allow mobile users and branch users (who are connected to the Prisma cloud) to reachprivate, centralized resourcesthat still reside on-premise, such as Active Directory controllers, legacy databases, or mainframes. Without a Service Connection, users in the cloud would be able to reach the internet and each other, but not the servers physically located in your HQ data center. The CloudBlade automates the creation of these tunnels, but architecturally, the "Service Connection" is the "cloud-to-HQ" bridge.

Comprehensive and Detailed Explanation

Prisma SD-WAN supports Dynamic VPNs (Branch-to-Branch) even when both endpoints are behind Source NAT (e.g., typical broadband connections).

To achieve this, the ION devices utilize standard NAT Traversal techniques, specifically leveraging STUN (Session Traversal Utilities for NAT).

Discovery:Each ION communicates with the Cloud Controller (which acts as a STUN server/signaling broker). Through this communication, the controller observes thepublicIP and Port that the ION's traffic is coming from (the post-NAT address).

Signaling:The controller shares this public reachability information with the peer ION.

Hole Punching:The IONs then attempt to initiate connections to each other's discovered public IP/Port. This "UDP Hole Punching" allows them to establish a direct IPSec tunnel through the NAT devices without requiring static 1:1 NAT mapping or manual port forwarding on the provider routers, enabling mesh connectivity in commodity internet environments.

Comprehensive and Detailed Explanation

Prisma SD-WAN utilizes a hierarchical QoS model (typically based onHierarchical Token Bucketor similar shaping algorithms) to manage bandwidth contention.

Guaranteed Bandwidth:The "Platinum" class (used for Real-Time voice/video) is assigned aguaranteed bandwidth percentage(floor) in the QoS profile. This ensures that even if "Gold" (Transactional) or "Silver" (Bulk) traffic is trying to consume 100% of the link, the scheduler reserves the specific portion (e.g., 30%) for Platinum traffic, preventing starvation.

Shaping, not Policing:Unlike simple policing which drops excess traffic hard, the ION deviceshapesthe egress traffic. If the link is congested, the scheduler delays the lower-priority packets (buffering) to allow the high-priority Platinum packets to exit immediately.

Why not Strict Priority (A)?While Platinum behaveslikea priority queue, pure Strict Priority can completely starve lower queues if the high-priority traffic is misbehaving or voluminous. Prisma SD-WAN typically uses bandwidth guarantees (floors) and limits (ceilings) to ensure fair sharing while protecting critical apps.