Practical TCP/IP and Ethernet Networking for Industry

Application layer protocols 153

cannot provide values for all the object instances in a list, it does not provide

any values

• The GetNext operation is used by the NMS to retrieve the value of the next

object instance in a table or list within an agent

• The Set operation is used by the NMS to set the values of object instances

within an agent

• The Trap operation is used by agents to asynchronously inform the NMS of

a significant event

The Get, GetNext, and Set operations used in SNMPv2 are exactly the same as that

used in SNMPv1. SNMPv2, however, adds and enhances some operations. The SNMPv2

Trap operation, for example, serves the same function as that used in SNMPv1. It,

however, uses a different message format and is designed to ...