snmp-check (snmp_enum Module) is the best tool to help the ethical hacker to get the information without directly modifying any parameters within the SNMP agent’s MIB. snmp-check is a tool that allows the user to enumerate SNMP devices and extract information from them. It can gather a wide array of information about the target, such as system information, network interfaces, routing tables, ARP cache, installed software, running processes, TCP and UDP services, user accounts, and more. snmp-check can also perform brute force attacks to discover the SNMP community strings, which are the passwords used to access the SNMP agent. snmp-check is available as a standalone tool or as a module (snmp_enum) within the Metasploit framework.

The other options are not as effective or suitable as snmp-check for the ethical hacker’s task. Nmap is a network scanning and enumeration tool that can perform various types of scans and probes on the target. It can also run scripts to perform specific tasks, such as retrieving SNMP information. However, Nmap may not be able to gather as much information as snmp-check, and it may also trigger alerts or blocks from firewalls or intrusion detection systems. Oputils is a network monitoring and management toolset that can perform various functions, such as device discovery, configuration backup, bandwidth monitoring, IP address management, and more. However, Oputils is mainly designed for device management and not SNMP enumeration, and it may not be able to extract valuable network information from the SNMP agent. SnmpWalk is a tool that allows the user to retrieve the entire MIB tree of an SNMP agent by using SNMP GETNEXT requests. However, SnmpWalk is not suitable for the ethical hacker’s task, because it requires the user to change an OID (object identifier) to a different value, which may modify the parameters within the SNMP agent’s MIB and affect its functionality or security. References:

snmp-check - The SNMP enumerator

SNMP Enumeration | Ethical Hacking - GreyCampus

SNMP Enumeration - GeeksforGeeks

Nmap - the Network Mapper - Free Security Scanner

OpUtils - Network Monitoring & Management Toolset

SnmpWalk - SNMP MIB Browser