snmp

方向

• SNMP是内网设备控制外网设备的协议。(right?)
• http://en.wikipedia.org/wiki/Simple_Network_Management_Protocol

concept

MIB
    The conceptual repository for management information is called the Management Information Base (MIB). It does not hold any data, merely a definition of what data can be accessed. A definition of an MIB is a description of a collection of managed objects. 
SMI
    The MIB is specified in an adapted subset of the Abstract Syntax Notation One (ASN.1) language. This adapted subset is called the Structure of Management Information (SMI). 
ASN.1
    ASN.1 is used in two different ways in SNMP. The SMI is based on ASN.1, and the messages in the protocol are defined by using ASN.1. 
Managed object
    A resource to be managed is represented by a managed object, which resides in the MIB. In an SNMP MIB, the managed objects are either:

        scalar variables, which have only one instance per context. They have single values, not multiple values like vectors or structures.
        tables, which can grow dynamically.
        a table element, which is a special type of scalar variable.

Operations
    SNMP relies on the three basic operations: get (object), set (object, value) and get-next (object). 
Instrumentation function
    An instrumentation function is associated with each managed object. This is the function, which actually implements the operations and will be called by the agent when it receives a request from the management station. 
Manager
    A manager generates commands and receives notifications from agents. There usually are only a few managers in a system. 
Agent
    An agent responds to commands from the manager, and sends notification to the manager. There are potentially many agents in a systrem. 

resource

• SNMP User's Guide
• net-snmp
  • 我没编译通过，好jiong。
• ObjectSNMP
  • TODO
• SNMP++
  • TODO
• snmp4j
  • Snmp学习
    • 使用snmp4j实现Snmp功能
    • jayway introduction-to-snmp4j
      • demo from jarway
  • 开源demo Android-SNMP
    • usage, 1.install agent to android device, 2. java -jar Android_SNMP_Manager.jar
  • SNMP4J-CLT 2.0 (User License) ， 适合在服务器跑cmd，但是收费的。 自己简单基于上面提到的开源demo实现了个clt，链接

tools

• ireasoning
  • We offer trial versions of every product, so you can test-drive the software before you purchase it. Every trial version is completely free, fully functional, and runs for 30 days.
• Mib browser
• Mib compiler

TODO

• snmp NAT? how to?