Dictionary · Protocols and Ports
SNMP
SNMP — Simple Network Management Protocol
Management · Intermediate
A protocol for monitoring and sometimes configuring network devices. Polling uses UDP 161, and a device can send traps to UDP 162. Old community strings are weak shared secrets.
A management station asks routers and switches how busy they are, and devices can push an alert when something changes. Version 3 adds real authentication and encryption.
Example: A monitor polls a switch for interface traffic and receives a trap when a link goes down.
Ports
- UDP 161 — Polling
- UDP 162 — Traps
Common misconception
- A community string in version 2c is not strong authentication. Treat it like a widely shared password.