Introduction to SNMP and Network Management

本章介绍了3个主题

What is SNMP

Network Management

Change Management

Obviously, SNMP is the focus of this book, but having an understanding of general network management concepts will make you better prepared to use SNMP to manage your network.

SNMP is really about network management. But before learning about the details of SNMP, it's helpful to have an overview of network management itself.

虽然network management也是技术，但是对于“用SNMP实现或帮助network management”来说，它应该算是业务。从开发“基于SNMP的软件”的程序员眼里，NM是业务！

【使用SNMP的环境】

In today's complex network of routers, switches, and servers, it can seem like a daunting task to manage all the devices on your network and make sure they're not only up and running but also performing optimally

【What is SNMP】

The core of SNMP is a simple set of operations (and the information these operations gather) 目的是：that gives administrators the ability to change the state of some SNMP-based device. 例如：you can use SNMP to shut down an interface on your router or check the speed at which your Ethernet interface is operating. SNMP can even monitor the temperature on your switch and warn you when it is too high.
【网络管理的两个方面】
Management
Monitoring -- Remote Network Monitoring
【SNMP的三个版本】
【Managers & Agents】
 Manager (NMS, Network Management Station) : a server running some kind of software system that can handle management tasks for a network.
Poll : an act of querying an agent for some piece of information
Trap : a way for the agent to tell the NMS that something has happend. Traps are sent asynchronously.
Agent : a software that runs on the network devices you are managing.
Poll and Trap can happen at the same time.
 
【SMI & MIB】
SMI : Structure of Management Information, a way to define managed objects and their behavior, syntax, How to define
MIB : Management Information Base, as a database of managed objects that the agent tracks.
两者间的关系：The SMI provides a way to define(HOW TO DEFINE) managed objects while the MIB is the definition of the objects themselves.
Agent may implement many MIBs, MIB-II, proprietary MIB
【RMON & probs】
下面介绍了Network Management和Change Managment。
五种管理：FCAPS
一些关键词：trend, risk level
Cisco的两份白皮书：

Network Management Basics
Change Management