SD-WAN-Engineer Hard Questions — 25 Difficult Questions

Question 1

Which THREE types of traffic are commonly categorized for specific QoS treatment?

Accepted Answer

Mission-critical database traffic. QoS focuses on real-time and business-critical traffic.

Answer

Public guest Wi-Fi browsing

Answer

Idle background system updates

Question 2

When DCI is implemented via an L3VPN overlay, which OMP attribute is most critical to ensure traffic prefers the direct link over the DCI link for reaching local subnets?

Accepted Answer

TLOC Preference.. OMP TLOC preference is used to influence path selection across different transports and links.

Answer

Color.

Answer

Site ID.

Answer

OMP Tag.

Question 3

Which THREE settings are typically defined during the initial ION site provisioning?

Accepted Answer

WAN interface settings. Provisioning involves setting up basic connectivity, identifying the site, and assigning basic policies.

Answer

Annual maintenance schedule

Answer

Global DNS server settings

Question 4

Which THREE factors must be considered when deploying a high-availability (HA) pair?

Accepted Answer

Direct heartbeat link between the two routers.. HA deployment requires specific physical connectivity, synchronization settings, and role management.

Answer

Different system IPs for each unit.

Answer

Identical hardware models for the HA pair.

Question 5

If a user at a branch site reports that they cannot access a specific internal server, which diagnostic tool should you use first?

Accepted Answer

Review Flow Monitoring logs. Flow monitoring allows you to see if traffic is hitting the expected policy and where it is being dropped or steered.

Answer

Check the cloud status page

Answer

Check physical cables

Answer

Reboot the ION

Question 6

Which THREE actions can be performed by a Prisma SD-WAN 'Policy' object?

Accepted Answer

Path selection. Policies can steer traffic, prioritize it, or apply security constraints.

Answer

Hardware replacement

Answer

Firmware updates

Question 7

When integrating Prisma SD-WAN with a cloud-based security service provider (CSSP) via CloudBlades, which setting must be verified to ensure proper traffic redirection?

Accepted Answer

Service-to-Tunnel Mapping. The service mapping in CloudBlades ensures that traffic classified for security inspection is steered to the correct CSSP node.

Answer

Local ISP DNS settings

Answer

DHCP Server scope

Answer

VLAN ID matching

Question 8

When planning for a large-scale deployment, which items are required for the initial site information gather? (Choose THREE)

Accepted Answer

Total bandwidth per link. Knowing local WAN IPs, LAN subnets, and bandwidth requirements is essential for design.

Answer

Local desk configurations

Answer

Employee names

Question 9

What is the primary benefit of enabling 'Forward Error Correction' (FEC) on a high-latency WAN link?

Accepted Answer

It improves performance for jitter-sensitive traffic. FEC adds redundant data to packets, allowing the receiver to reconstruct lost packets without retransmission.

Answer

It bypasses the firewall

Answer

It replaces the need for QoS

Answer

It reduces total bandwidth usage

Question 10

When using Prisma SD-WAN with Prisma Access, how is the secure tunnel established?

Accepted Answer

Automated tunnel provisioning via the Controller. The ION device automatically provisions an IPsec tunnel to the Prisma Access Cloud Service Edge (CSE).

Answer

Manual IPsec configuration

Answer

Using a BGP peer

Answer

Via a physical cable link

Question 11

In a multi-VRF deployment, what must be configured to allow traffic to move between two different VRFs?

Accepted Answer

Configure inter-VRF routing policies. Cross-VRF communication requires explicit route leaking or inter-VRF routing policies.

Answer

Enable NAT on both interfaces

Answer

Assign both to the default VRF

Answer

Disable the firewall

Question 12

Which THREE components are involved in configuring Prisma SD-WAN security policies?

Accepted Answer

Application objects. Security policies rely on application identification, zone definitions, and action rules.

Answer

Physical port numbering

Answer

Hard drive capacity

Question 13

During an HA failover, sessions are dropping. You suspect the state synchronization is not occurring fast enough. Which configuration parameter should you check?

Accepted Answer

The HA heartbeat and hold-time intervals.. The HA keepalive and heartbeats define the timing of the failover process.

Answer

The BFD multiplier.

Answer

The OMP advertisement interval.

Answer

The NTP synchronization status.

Question 14

Which THREE types of information are displayed in the Prisma SD-WAN 'Flow Monitoring' view?

Accepted Answer

Source and destination IP. Flow monitoring provides details on path, performance, and application statistics.

Answer

ISP billing records

Answer

Router CPU temperature

Question 15

You have a DCI configuration where two data centers are connected via a dedicated link. You want to ensure the DCI link is only used if the primary WAN transport fails. How do you achieve this?

Accepted Answer

Configure a lower TLOC preference on the DCI link routes.. OMP TLOC preference can be used to steer traffic to specific paths based on preference values.

Answer

Disable OMP on the primary link.

Answer

Set the OMP cost to zero.

Answer

Use a static route with a high administrative distance.

Question 16

Which THREE items are included in a Prisma SD-WAN 'Site' configuration?

Accepted Answer

Interface configuration. A site definition includes location, hardware assignment, and local interface definitions.

Answer

ISP contract end date

Answer

User password history

Question 17

In a multi-homed DCI scenario, you are seeing asymmetric routing. What is the most likely cause within the OMP domain?

Accepted Answer

The TLOC preference is higher on one of the exit points, causing traffic to prefer that path for return.. Asymmetry occurs when the return path preference differs from the forward path due to OMP path attribute configurations.

Answer

The MTU size is different on the DCI interfaces.

Answer

The site IDs are identical.

Answer

BFD is disabled on one of the links.

Question 18

Which THREE actions occur when a device transitions to 'Active' status in an HA pair?

Accepted Answer

The device restarts its BFD sessions.. The transition triggers BFD, OMP advertisement, and interface reactivation.

Answer

The device initiates a factory reset.

Answer

The device purges all log history.

Question 19

Which THREE OMP attributes can be used to influence path selection for DCI?

Accepted Answer

TLOC Preference.. TLOC preference, OMP cost, and OMP tag are standard attributes for path manipulation.

Answer

System IP.

Answer

Device Serial Number.

Question 20

You observe that a device is frequently 'Flapping' between HA active and standby roles. What should you examine first?

Accepted Answer

The status of the physical heartbeat cable and the HA timers.. Unstable HA roles are usually caused by timing issues or physical connectivity problems on the HA heartbeat link.

Answer

The system CPU usage.

Answer

The vManage connectivity.

Answer

The BGP neighbor status.