SNMP Enumeration

What is SNMP and what does it do?

SNMP was designed to manage IP-enable devices across a network

How does SNMP work?

It works by having a central management systems that makes requests of SNMP agents on the devices

The agents then respond to the requests by going through the Management Information Base (MIB)

The MIB holds information, and is arranged with numeric identifiers called object identifiers (OIDs)

There are two type of SNMP packets or requests

SNMP GET - when the SNMP management station asks a device for information
SNMP SET - when the SNMP management station asks to make a configuration change

There are two types of managed object in SNMP

Scalar - defines a single object
Tabular - multiple related objects that can be grouped together in MIB tables

SNMP uses a community string as a form of password

The read-only version of the community string is public and allows the requester to read anything that SNMP can grab from the device
The read-write version is private and is used to control access for the SNMP SET requests.

There are two major downsides in the use of these community string passwords

Defaults (which are active on all SNMP enabled devices by default) are extremely easy
These strings are sent in clear text (NTPv3 and SMTPv3 provide encryption)

SNMP Enumeration tools

Last updated 11 months ago