"Simple Network Management Protocol"

Utilizes MIB (Memory Information Base) - A specialized database containing information about a device's operations

We can query the MIB from a centralized "network management console"

We query/"poll" specific values by referencing OIDs (object identifiers)

SNMP utilizes udp/161

3 versions of SNMP

• v1 - The OG, structured tables, unencrypted
• v2c - Data type enhancements, larger data transfers, unencrypted
• v3 - The new standard, includes capabilities for message integrity, authentication, and encryption

More on OIDs

OIDs allow use to reference specific variables we want to pull from a device

OIDs can be referenced by name or number

• Ex: 1.3.6.1.2.1.11.28.0
• Each number is out of a specific set of values

Every variable in the MIB has a corresponding OID, some of which are common across devices and some of which are unique to a manufacturer

MIB Walker - Cycles through every entry in the MIB and pulls the values

SNPM Traps - An "alarm" sent by a monitored device

• Typically devices wait for a request for data
• By configuring an SNMP trap, we can have the device initiate a conversation instead when something specific happens
• Uses udp/162

Authentication

SNMP v1 and v2 use a community string, which is like a simple password authentication

• Common strings are "public" and "private"

v3 introduced a username and password that is hashed