CEH Enumeration and System Hacking Practice Question
Which SNMP community string is typically used for read-only access by default on many devices?
⚠ Common exam trap
Many exam-takers confuse 'public' with 'private', mistakenly thinking 'private' is the read-only string, when in fact 'private' is the default read-write community string.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
public
The default read-only community string in SNMPv1 and SNMPv2c is 'public'. This string acts as a password that allows an SNMP manager to query device MIB objects for monitoring purposes without making configuration changes. It is widely documented in RFC 1157 and is the standard default across most networking equipment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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snmp
Why it's wrong here
The string "snmp" is not a standard or commonly configured default SNMP community string for either read-only or read-write access. While an administrator *could* configure any string, "snmp" itself does not carry any inherent default permissions or widespread recognition in the same way "public" or "private" do. Therefore, attempting to use "snmp" as a community string would typically fail unless explicitly set by a network administrator, which is uncommon.
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private
Why it's wrong here
The "private" community string is conventionally associated with read-write access in SNMPv1 and SNMPv2c implementations. This string grants the ability not only to retrieve information from a device's MIB but also to modify configuration parameters or control device functions. Consequently, "private" is not used for read-only operations, as it provides elevated privileges beyond simple data retrieval.
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admin
Why it's wrong here
The string "admin" is not a standard or default SNMP community string. While "admin" is a common username or role in many other network protocols and operating systems, it holds no special significance or default configuration within the Simple Network Management Protocol. SNMP community strings are essentially clear-text passwords for accessing MIB objects, and "admin" is not one of the widely recognized defaults for either read-only or read-write access.
- ✓
public
Why this is correct
The "public" community string is the universally recognized and default read-only community string for SNMPv1 and SNMPv2c agents. This string allows an SNMP manager to query and retrieve various operational statistics and configuration details from a network device's Management Information Base (MIB) without the ability to alter any settings. Due to its widespread default configuration, "public" is frequently targeted by attackers seeking to gather network intelligence.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.