The answer is that the default route is not active because the interface ethernet1/1 is down. In Palo Alto Networks firewalls, a static route is only installed into the forwarding table—and marked with the 'C' flag for candidate—when the specified egress interface is both administratively up and operationally active; if the interface goes down, the route is automatically deactivated, leaving the firewall with no path to the Internet. On the PCNSA exam, this scenario tests your understanding of route selection prerequisites, often appearing in a routing table exhibit where a static route exists but lacks the 'C' flag. A common trap is assuming a configured route is always usable, but the firewall strictly requires a live interface. Remember the memory tip: "No link, no route—if the interface is down, the static route won't be found."
PCNSA Palo Alto Networks Platforms and Architecture Practice Question
This PCNSA practice question tests your understanding of palo alto networks platforms and architecture. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Exhibit
Refer to the exhibit.
admin@PA-3220> show routing route table default
IPv4 Route Table for virtual-router default (0 entries)
No routes
admin@PA-3220> show routing route
destination nexthop metric flags interface
0.0.0.0/0 10.1.1.1 10 A ethernet1/1
10.1.1.0/24 0.0.0.0 0 C ethernet1/1
192.168.1.0/24 0.0.0.0 0 C ethernet1/2
Refer to the exhibit. The firewall cannot reach the Internet. Based on the routing table, what is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Refer to the exhibit.
admin@PA-3220> show routing route table default
IPv4 Route Table for virtual-router default (0 entries)
No routes
admin@PA-3220> show routing route
destination nexthop metric flags interface
0.0.0.0/0 10.1.1.1 10 A ethernet1/1
10.1.1.0/24 0.0.0.0 0 C ethernet1/1
192.168.1.0/24 0.0.0.0 0 C ethernet1/2
A
The default route is not active because the interface ethernet1/1 is down
The route flags show 'A' (active), but the table indicates 0 routes, so the route might be inactive; interface down is a common cause.
B
The next hop 10.1.1.1 is not reachable
Why wrong: While possible, the more direct cause from the exhibit is the routing table showing 0 entries, suggesting the route is not installed.
C
There is no default route configured
Why wrong: The route to 0.0.0.0/0 is present.
D
The route table is empty because the virtual-router is misconfigured
Why wrong: The virtual-router exists but shows 0 entries, indicating the routes are not active, likely due to interface state.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The default route is not active because the interface ethernet1/1 is down
The routing table shows a default route (0.0.0.0/0) configured with a next hop of 10.1.1.1 via interface ethernet1/1, but the route is not active (no 'C' flag for candidate). In Palo Alto Networks firewalls, a static route is only installed into the forwarding table if the specified egress interface is administratively up and operationally active. Since ethernet1/1 is down, the route cannot be used, and the firewall has no path to the Internet.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The default route is not active because the interface ethernet1/1 is down
Why this is correct
The route flags show 'A' (active), but the table indicates 0 routes, so the route might be inactive; interface down is a common cause.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The next hop 10.1.1.1 is not reachable
Why it's wrong here
While possible, the more direct cause from the exhibit is the routing table showing 0 entries, suggesting the route is not installed.
✗
There is no default route configured
Why it's wrong here
The route to 0.0.0.0/0 is present.
✗
The route table is empty because the virtual-router is misconfigured
Why it's wrong here
The virtual-router exists but shows 0 entries, indicating the routes are not active, likely due to interface state.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates see a default route in the routing table and assume it is active, overlooking the critical detail that the interface is down, which prevents the route from being used for forwarding.
Trap categories for this question
Command / output trap
While possible, the more direct cause from the exhibit is the routing table showing 0 entries, suggesting the route is not installed.
Detailed technical explanation
How to think about this question
In Palo Alto Networks, static routes are evaluated based on the administrative distance and the state of the egress interface. Even if the next hop is reachable via a different path, the route will not be installed if the specific interface is down. This behavior is similar to Cisco's 'interface-dependent static route' where the route is removed from the routing table when the interface goes down, preventing blackholing of traffic. In production, this ensures that failover to a backup default route (e.g., via a different interface) occurs only when the primary path is fully functional.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Palo Alto Networks Platforms and Architecture — This question tests Palo Alto Networks Platforms and Architecture — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The default route is not active because the interface ethernet1/1 is down — The routing table shows a default route (0.0.0.0/0) configured with a next hop of 10.1.1.1 via interface ethernet1/1, but the route is not active (no 'C' flag for candidate). In Palo Alto Networks firewalls, a static route is only installed into the forwarding table if the specified egress interface is administratively up and operationally active. Since ethernet1/1 is down, the route cannot be used, and the firewall has no path to the Internet.
What should I do if I get this PCNSA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This PCNSA practice question is part of Courseiva's free Palo Alto Networks certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCNSA exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.