SNMP packets are transmitted by UDP.

The statement is true. The Simple Network Management Protocol (SNMP) is an application-layer protocol that primarily uses the User Datagram Protocol (UDP) as its transport-layer protocol. UDP is a connectionless, lightweight protocol, which is suitable for the request-response nature of SNMP management traffic and reduces overhead. The standard port for SNMP requests from a manager to an agent is UDP 161, and the standard port for unsolicited traps from an agent to a manager is UDP 162.

The "False" option is incorrect because the standard and vast majority of SNMP implementations operate over UDP. While transport over other protocols like TCP is defined (e.g., SNMP-over-TCP), UDP is the default and most common transport.

1. Huawei HCIA-Datacom V1.0 Training Material, "Network Management and O&M", Section: SNMP Protocol Principles. This material explicitly states that SNMP is based on UDP and lists the standard ports UDP 161 and UDP 162.

2. IETF RFC 3417, "Transport Mappings for the Simple Network Management Protocol (SNMP)", Section 3: "UDP Mapping". This document specifies the standard transport mapping for SNMP, stating, "An implementation of this mapping MUST support the sending and receiving of SNMP messages using the User Datagram Protocol."