This 350-601 practice question tests your understanding of security. 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.
A data center engineer is troubleshooting connectivity issues between two EPGs in the same tenant on a Cisco ACI fabric. The first EPG 'web_epg' is in VLAN 100 and the second EPG 'db_epg' is in VLAN 200. The contract 'web_to_db' allows TCP port 3306 from web_epg to db_epg. The EPGs are in the same VRF. The engineer has verified that the physical connectivity is correct and the endpoints are learning their IP addresses. However, traffic from web_epg to db_epg is not reaching the destination. The engineer checks the contract and sees that the subject 'mysql_access' has filter 'mysql' with direction 'both'. The provider is db_epg and consumer is web_epg. The engineer also notices that the default action in the contract is 'deny'. What is the most likely cause of the issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "first"
Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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.
The contract direction is reversed: the provider should be the destination of the traffic. Since web_epg initiates to db_epg, web_epg should be the provider.
In ACI, the provider offers a service; the consumer initiates. Here web_epg initiates, so web_epg should be provider.
B
The VRF is not correctly associated with the EPGs.
Why wrong: EPGs are in the same VRF, so routing is fine.
C
A Layer 3 Outside (L3Out) is required for communication between EPGs in the same VRF.
Why wrong: L3Out is for external connectivity, not internal EPG communication.
D
The filter 'mysql' does not match TCP port 3306.
Why wrong: The filter likely matches 3306, given it's named mysql.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The contract direction is reversed: the provider should be the destination of the traffic. Since web_epg initiates to db_epg, web_epg should be the provider.
In Cisco ACI, the provider EPG is the one that offers a service (the destination of the traffic), and the consumer EPG is the one that initiates the connection. Since web_epg initiates TCP traffic to db_epg, db_epg should be the provider and web_epg the consumer. The contract is reversed, so the default deny action blocks the traffic because the consumer (web_epg) is not allowed to initiate toward the provider (db_epg) under the reversed roles.
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 contract direction is reversed: the provider should be the destination of the traffic. Since web_epg initiates to db_epg, web_epg should be the provider.
Why this is correct
In ACI, the provider offers a service; the consumer initiates. Here web_epg initiates, so web_epg should be provider.
Clue confirmation
The clue words "first", "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The VRF is not correctly associated with the EPGs.
Why it's wrong here
EPGs are in the same VRF, so routing is fine.
✗
A Layer 3 Outside (L3Out) is required for communication between EPGs in the same VRF.
Why it's wrong here
L3Out is for external connectivity, not internal EPG communication.
✗
The filter 'mysql' does not match TCP port 3306.
Why it's wrong here
The filter likely matches 3306, given it's named mysql.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the provider/consumer directionality in ACI contracts, and the trap here is that candidates assume the provider is the source (initiator) of traffic, when in fact the provider is the destination (service offerer).
Detailed technical explanation
How to think about this question
ACI contracts enforce a provider/consumer model where the provider (destination) defines the service and the consumer (source) initiates the communication. The contract subject's direction 'both' allows return traffic, but the default deny action only applies when the contract is correctly oriented; reversed roles cause the consumer's initial packets to be dropped because the contract does not grant permission from the consumer to the provider. In real-world deployments, misconfigured contract direction is a common issue that can be verified by checking the contract's consumer and provider EPG assignments in the APIC GUI or via the 'show contract' CLI.
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
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.
Security — This question tests Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The contract direction is reversed: the provider should be the destination of the traffic. Since web_epg initiates to db_epg, web_epg should be the provider. — In Cisco ACI, the provider EPG is the one that offers a service (the destination of the traffic), and the consumer EPG is the one that initiates the connection. Since web_epg initiates TCP traffic to db_epg, db_epg should be the provider and web_epg the consumer. The contract is reversed, so the default deny action blocks the traffic because the consumer (web_epg) is not allowed to initiate toward the provider (db_epg) under the reversed roles.
What should I do if I get this 350-601 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: "first", "most likely". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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 350-601 practice question is part of Courseiva's free Cisco 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 350-601 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.