Quick Answer
The answer is SNMP enumeration. This is correct because the scenario describes querying a target over UDP port 161 using the default community string 'public' with the `snmpwalk` command, which retrieves extensive system information from the Management Information Base (MIB). SNMP enumeration exploits misconfigured devices that leave the default read-only community string unchanged, allowing an attacker to extract sensitive data such as running processes, user accounts, and network configurations. On the Certified Ethical Hacker CEH exam, this technique tests your understanding of how SNMP services can be leveraged for information gathering during the reconnaissance phase; a common trap is confusing SNMP enumeration with SNMP brute-forcing, but the key distinction here is the use of a known default string rather than guessing multiple strings. Remember the memory tip: "Public on 161, snmpwalk is done" — if you see UDP 161 with 'public' and a walk, it is always SNMP enumeration.
This CEH practice question tests your understanding of enumeration and system hacking. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 penetration tester discovers a service running on UDP port 161 with a default community string 'public'. They use `snmpwalk -v2c -c public 192.168.1.10` and retrieve extensive system information. Which enumeration technique is being performed?
SMB enumeration
Why wrong: SMB uses TCP 445.
LDAP enumeration
Why wrong: LDAP uses TCP 389.
SMTP enumeration
Why wrong: SMTP uses TCP port 25, not UDP 161.
SNMP enumeration
SNMP uses UDP 161, and snmpwalk retrieves the entire MIB tree.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
SNMP enumeration
The correct answer is D because the question describes using SNMP (Simple Network Management Protocol) over UDP port 161 with the default community string 'public' and the `snmpwalk` command to retrieve system information. This is a classic SNMP enumeration technique, where an attacker queries MIB (Management Information Base) data to extract details like running processes, user accounts, and network configurations.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Common exam traps
The trap here is that candidates may confuse SNMP enumeration with other enumeration techniques because they see 'enumeration' in the question, but the specific use of UDP port 161 and the `snmpwalk` command uniquely identifies SNMP enumeration.
Detailed technical explanation
SNMP enumeration leverages the fact that many devices ship with default community strings (e.g., 'public' for read-only, 'private' for read-write). The `snmpwalk` command performs a GETNEXT request chain to traverse the entire MIB tree, exposing OIDs (Object Identifiers) that can reveal system information such as hostname, interfaces, processes, and user accounts. In real-world assessments, this is often the first step in identifying misconfigured SNMP agents that can lead to full device compromise if the write community string is also default.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the CEH exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
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FAQ
Enumeration and System Hacking — This question tests Enumeration and System Hacking — Read the scenario before looking for a memorised answer..
The correct answer is: SNMP enumeration — The correct answer is D because the question describes using SNMP (Simple Network Management Protocol) over UDP port 161 with the default community string 'public' and the `snmpwalk` command to retrieve system information. This is a classic SNMP enumeration technique, where an attacker queries MIB (Management Information Base) data to extract details like running processes, user accounts, and network configurations.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 24, 2026
This CEH practice question is part of Courseiva's free EC-Council 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 CEH exam.
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