【转载】 java利用snmp4j包来读取snmp协议数据（Manager端）

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【转载】 java利用snmp4j包来读取snmp协议数据（Manager端）
https://www.cnblogs.com/xdp-gacl/p/4187089.html
http://doc.okbase.net/yuanfy008/archive/265663.html
java利用snmp4j包来读取snmp协议数据（Manager端）
1 snmp简单介绍
java利用snmp4j包来读取snmp协议数据，很简单的一个流程，就是利用java来读取运行snmp协议的数据，例如服务器、PC机或者路由器等运行了snmp协议的设备。
snmp协议是什么呢？
简单网络管理协议（SNMP），由一组网络管理的标准组成，包含一个应用层协议（application layer protocol）、数据库模型（database schema）和一组资源对象。该协议能够支持网络管理系统，用以监测连接到网络上的设备是否有任何引起管理上关注的情况。该协议是互联网工程工作小组（IETF，Internet Engineering TaskForce）定义的internet协议簇的一部分。SNMP的目标是管理互联网 Internet上众多厂家生产的软硬件平台，因此SNMP受Internet标准网络管理框架的影响也很大。SNMP已经出到第三个版本的协议，其功能较以前已经大大地加强和改进了。
上面是百度百科上对于snmp的一个定义，其实很简单，就是用来管理网络、查看网络信息的一种协议。
2 在本机上开启snmp协议
那么如何在本机上开启snmp协议呢？
首先，在控制面板中找到“卸载程序”；
在弹出的窗口中单击“打开或关闭Windows功能”；
勾选弹出窗口中的“简单网络管理协议（SNMP）”项后单击“确定”并根据提示完成安装即可。
完成SNMP服务的安装后，右键单击“计算机”选择“管理”

在弹出的“计算机管理”窗口中左侧导航栏中找到“服务”，并在右侧找到“SNMPService”项；
鼠标双击“SNMPService”选项，在弹出的窗口中切换到“安全”选项卡中，如下图添加“接受的社区名称”和接收那些主机发出的SNMP数据包。
“接受的社区名称”是自己定义的任意字符都可以，接收那些主机发出的SNMP数据包定义成你的Nagios服务器即可。到这里被监控端的Windows主机的SNMP服务就配置完成了。
其中要注意的地方就是，在开启后，还要到服务里面给snmp协议添加public权限。
3 snmp4j.jar包的下载
包用的是snmp4j.jar，下载地址是：http://www.snmp4j.org

4 编码测试
SnmpData：
[java] view plain copy
package com.test.snmp;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.event.ResponseListener;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.Integer32;
import org.snmp4j.smi.Null;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class SnmpData {

      public static final int DEFAULT_VERSION = SnmpConstants.version2c;
      public static final String DEFAULT_PROTOCOL = "udp";
      public static final int DEFAULT_PORT = 161;
      public static final long DEFAULT_TIMEOUT = 3 * 1000L;
      public static final int DEFAULT_RETRY = 3;

      /**
       * 创建对象communityTarget，用于返回target
       *
       * @param targetAddress
       * @param community
       * @param version
       * @param timeOut
       * @param retry
       * @return CommunityTarget
       */
      public static CommunityTarget createDefault(String ip, String community) {
        Address address = GenericAddress.parse(DEFAULT_PROTOCOL + ":" + ip
            + "/" + DEFAULT_PORT);
        CommunityTarget target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(address);
        target.setVersion(DEFAULT_VERSION);
        target.setTimeout(DEFAULT_TIMEOUT); // milliseconds
        target.setRetries(DEFAULT_RETRY);
        return target;
      }
      /*根据OID，获取单条消息*/
      public static void snmpGet(String ip, String community, String oid) {

        CommunityTarget target = createDefault(ip, community);
        Snmp snmp = null;
        try {
          PDU pdu = new PDU();
          // pdu.add(new VariableBinding(new OID(new int[]
          // {1,3,6,1,2,1,1,2})));
          pdu.add(new VariableBinding(new OID(oid)));

          DefaultUdpTransportMapping transport = new DefaultUdpTransportMapping();
          snmp = new Snmp(transport);
          snmp.listen();
          System.out.println("-------> 发送PDU <-------");
          pdu.setType(PDU.GET);
          ResponseEvent respEvent = snmp.send(pdu, target);
          System.out.println("PeerAddress:" + respEvent.getPeerAddress());
          PDU response = respEvent.getResponse();

          if (response == null) {
            System.out.println("response is null, request time out");
          } else {

            // Vector<VariableBinding> vbVect =
            // response.getVariableBindings();
            // System.out.println("vb size:" + vbVect.size());
            // if (vbVect.size() == 0) {
            // System.out.println("response vb size is 0 ");
            // } else {
            // VariableBinding vb = vbVect.firstElement();
            // System.out.println(vb.getOid() + " = " + vb.getVariable());
            // }

            System.out.println("response pdu size is " + response.size());
            for (int i = 0; i < response.size(); i++) {
              VariableBinding vb = response.get(i);
              System.out.println(vb.getOid() + " = " + vb.getVariable());
            }

          }
          System.out.println("SNMP GET one OID value finished !");
        } catch (Exception e) {
          e.printStackTrace();
          System.out.println("SNMP Get Exception:" + e);
        } finally {
          if (snmp != null) {
            try {
              snmp.close();
            } catch (IOException ex1) {
              snmp = null;
            }
          }

        }
      }
      /*根据OID列表，一次获取多条OID数据，并且以List形式返回*/
      public static void snmpGetList(String ip, String community, List<String> oidList)
      {
        CommunityTarget target = createDefault(ip, community);
        Snmp snmp = null;
        try {
          PDU pdu = new PDU();

          for(String oid:oidList)
          {
            pdu.add(new VariableBinding(new OID(oid)));
          }

          DefaultUdpTransportMapping transport = new DefaultUdpTransportMapping();
          snmp = new Snmp(transport);
          snmp.listen();
          System.out.println("-------> 发送PDU <-------");
          pdu.setType(PDU.GET);
          ResponseEvent respEvent = snmp.send(pdu, target);
          System.out.println("PeerAddress:" + respEvent.getPeerAddress());
          PDU response = respEvent.getResponse();

          if (response == null) {
            System.out.println("response is null, request time out");
          } else {

            System.out.println("response pdu size is " + response.size());
            for (int i = 0; i < response.size(); i++) {
              VariableBinding vb = response.get(i);
              System.out.println(vb.getOid() + " = " + vb.getVariable());
            }

          }
          System.out.println("SNMP GET one OID value finished !");
        } catch (Exception e) {
          e.printStackTrace();
          System.out.println("SNMP Get Exception:" + e);
        } finally {
          if (snmp != null) {
            try {
              snmp.close();
            } catch (IOException ex1) {
              snmp = null;
            }
          }

        }
      }
      /*根据OID列表，采用异步方式一次获取多条OID数据，并且以List形式返回*/
      public static void snmpAsynGetList(String ip, String community,List<String> oidList)
      {
        CommunityTarget target = createDefault(ip, community);
        Snmp snmp = null;
        try {
          PDU pdu = new PDU();

          for(String oid:oidList)
          {
            pdu.add(new VariableBinding(new OID(oid)));
          }

          DefaultUdpTransportMapping transport = new DefaultUdpTransportMapping();
          snmp = new Snmp(transport);
          snmp.listen();
          System.out.println("-------> 发送PDU <-------");
          pdu.setType(PDU.GET);
          ResponseEvent respEvent = snmp.send(pdu, target);
          System.out.println("PeerAddress:" + respEvent.getPeerAddress());
          PDU response = respEvent.getResponse();

          /*异步获取*/
          final CountDownLatch latch = new CountDownLatch(1);
          ResponseListener listener = new ResponseListener() {
            public void onResponse(ResponseEvent event) {
              ((Snmp) event.getSource()).cancel(event.getRequest(), this);
              PDU response = event.getResponse();
              PDU request = event.getRequest();
              System.out.println("[request]:" + request);
              if (response == null) {
                System.out.println("[ERROR]: response is null");
              } else if (response.getErrorStatus() != 0) {
                System.out.println("[ERROR]: response status"
                    + response.getErrorStatus() + " Text:"
                    + response.getErrorStatusText());
              } else {
                System.out.println("Received response Success!");
                for (int i = 0; i < response.size(); i++) {
                  VariableBinding vb = response.get(i);
                  System.out.println(vb.getOid() + " = "
                      + vb.getVariable());
                }
                System.out.println("SNMP Asyn GetList OID finished. ");
                latch.countDown();
              }
            }
          };

          pdu.setType(PDU.GET);
          snmp.send(pdu, target, null, listener);
          System.out.println("asyn send pdu wait for response...");

          boolean wait = latch.await(30, TimeUnit.SECONDS);
          System.out.println("latch.await =:" + wait);

          snmp.close();

          System.out.println("SNMP GET one OID value finished !");
        } catch (Exception e) {
          e.printStackTrace();
          System.out.println("SNMP Get Exception:" + e);
        } finally {
          if (snmp != null) {
            try {
              snmp.close();
            } catch (IOException ex1) {
              snmp = null;
            }
          }

        }
      }
      /*根据targetOID，获取树形数据*/
      public static void snmpWalk(String ip, String community, String targetOid)
      {
        CommunityTarget target = createDefault(ip, community);
        TransportMapping transport = null;
        Snmp snmp = null;
        try {
          transport = new DefaultUdpTransportMapping();
          snmp = new Snmp(transport);
          transport.listen();

          PDU pdu = new PDU();
          OID targetOID = new OID(targetOid);
          pdu.add(new VariableBinding(targetOID));

          boolean finished = false;
          System.out.println("----> demo start <----");
          while (!finished) {
            VariableBinding vb = null;
            ResponseEvent respEvent = snmp.getNext(pdu, target);

            PDU response = respEvent.getResponse();

            if (null == response) {
              System.out.println("responsePDU == null");
              finished = true;
              break;
            } else {
              vb = response.get(0);
            }
            // check finish
            finished = checkWalkFinished(targetOID, pdu, vb);
            if (!finished) {
              System.out.println("==== walk each vlaue :");
              System.out.println(vb.getOid() + " = " + vb.getVariable());

              // Set up the variable binding for the next entry.
              pdu.setRequestID(new Integer32(0));
              pdu.set(0, vb);
            } else {
              System.out.println("SNMP walk OID has finished.");
              snmp.close();
            }
          }
          System.out.println("----> demo end <----");
        } catch (Exception e) {
          e.printStackTrace();
          System.out.println("SNMP walk Exception: " + e);
        } finally {
          if (snmp != null) {
            try {
              snmp.close();
            } catch (IOException ex1) {
              snmp = null;
            }
          }
        }
      }

      private static boolean checkWalkFinished(OID targetOID, PDU pdu,
          VariableBinding vb) {
        boolean finished = false;
        if (pdu.getErrorStatus() != 0) {
          System.out.println("[true] responsePDU.getErrorStatus() != 0 ");
          System.out.println(pdu.getErrorStatusText());
          finished = true;
        } else if (vb.getOid() == null) {
          System.out.println("[true] vb.getOid() == null");
          finished = true;
        } else if (vb.getOid().size() < targetOID.size()) {
          System.out.println("[true] vb.getOid().size() < targetOID.size()");
          finished = true;
        } else if (targetOID.leftMostCompare(targetOID.size(), vb.getOid()) != 0) {
          System.out.println("[true] targetOID.leftMostCompare() != 0");
          finished = true;
        } else if (Null.isExceptionSyntax(vb.getVariable().getSyntax())) {
          System.out
              .println("[true] Null.isExceptionSyntax(vb.getVariable().getSyntax())");
          finished = true;
        } else if (vb.getOid().compareTo(targetOID) <= 0) {
          System.out.println("[true] Variable received is not "
              + "lexicographic successor of requested " + "one:");
          System.out.println(vb.toString() + " <= " + targetOID);
          finished = true;
        }
        return finished;

      }
      /*根据targetOID，异步获取树形数据*/
      public static void snmpAsynWalk(String ip, String community, String oid)
      {
        final CommunityTarget target = createDefault(ip, community);
        Snmp snmp = null;
        try {
          System.out.println("----> demo start <----");

          DefaultUdpTransportMapping transport = new DefaultUdpTransportMapping();
          snmp = new Snmp(transport);
          snmp.listen();

          final PDU pdu = new PDU();
          final OID targetOID = new OID(oid);
          final CountDownLatch latch = new CountDownLatch(1);
          pdu.add(new VariableBinding(targetOID));

          ResponseListener listener = new ResponseListener() {
            public void onResponse(ResponseEvent event) {
              ((Snmp) event.getSource()).cancel(event.getRequest(), this);

              try {
                PDU response = event.getResponse();
                // PDU request = event.getRequest();
                // System.out.println("[request]:" + request);
                if (response == null) {
                  System.out.println("[ERROR]: response is null");
                } else if (response.getErrorStatus() != 0) {
                  System.out.println("[ERROR]: response status"
                      + response.getErrorStatus() + " Text:"
                      + response.getErrorStatusText());
                } else {
                  System.out
                      .println("Received Walk response value :");
                  VariableBinding vb = response.get(0);

                  boolean finished = checkWalkFinished(targetOID,
                      pdu, vb);
                  if (!finished) {
                    System.out.println(vb.getOid() + " = "
                        + vb.getVariable());
                    pdu.setRequestID(new Integer32(0));
                    pdu.set(0, vb);
                    ((Snmp) event.getSource()).getNext(pdu, target,
                        null, this);
                  } else {
                    System.out
                        .println("SNMP Asyn walk OID value success !");
                    latch.countDown();
                  }
                }
              } catch (Exception e) {
                e.printStackTrace();
                latch.countDown();
              }

            }
          };

          snmp.getNext(pdu, target, null, listener);
          System.out.println("pdu 已发送,等到异步处理结果...");

          boolean wait = latch.await(30, TimeUnit.SECONDS);
          System.out.println("latch.await =:" + wait);
          snmp.close();

          System.out.println("----> demo end <----");
        } catch (Exception e) {
          e.printStackTrace();
          System.out.println("SNMP Asyn Walk Exception:" + e);
        }
      }
      /*根据OID和指定string来设置设备的数据*/
      public static void setPDU(String ip,String community,String oid,String val) throws IOException
      {
        CommunityTarget target = createDefault(ip, community);
        Snmp snmp = null;
        PDU pdu = new PDU();
        pdu.add(new VariableBinding(new OID(oid),new OctetString(val)));
        pdu.setType(PDU.SET);

        DefaultUdpTransportMapping transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(transport);
        snmp.listen();
        System.out.println("-------> 发送PDU <-------");
        snmp.send(pdu, target);
        snmp.close();
      }
}
SnmpTest：
[java] view plain copy
package com.test.snmp;

import java.util.ArrayList;
import java.util.List;
import org.snmp4j.log.ConsoleLogFactory;
import org.snmp4j.log.LogAdapter;
import org.snmp4j.log.LogFactory;
import com.test.snmp.SnmpData;

public class SnmpTest {

    /**
     * @param args
     */
    public static void main(String[] args) {

        // TODO Auto-generated method stub
        SnmpTest test = new SnmpTest();

        test.testGet();

    }

    public void testGet()
    {
    String ip = "127.0.0.1";
    String community = "public";
    String oidval = "1.3.6.1.2.1.1.6.0";
    SnmpData.snmpGet(ip, community, oidval);
    }


    public void testGetList(){
    String ip = "127.0.0.1";
     String community = "public";
     List<String> oidList=new ArrayList<String>();
     oidList.add("1.3.6.1.2.1.1.5.0");
     oidList.add("1.3.6.1.2.1.1.7.0");
      SnmpData.snmpGetList(ip, community, oidList);
    }


    public void testGetAsyList()
    {
    String ip = "127.0.0.1";
    String community = "public";
    List<String> oidList=new ArrayList<String>();
    oidList.add("1.3.6.1.2.1");
    oidList.add("1.3.6.1.2.12");
    SnmpData.snmpAsynGetList(ip, community, oidList);
    System.out.println("i am first!");
    }


    public void testWalk()
    {
    String ip = "127.0.0.1";
    String community = "public";
    String targetOid = "1.3.6.1.2.1.1.5.0";
    SnmpData.snmpWalk(ip, community, targetOid);
    }


    public void testAsyWalk()
    {
    String ip = "127.0.0.1";
    String community = "public";
    // 异步采集数据
    SnmpData.snmpAsynWalk(ip, community, "1.3.6.1.2.1.25.4.2.1.2");
    }


    public void testSetPDU() throws Exception
    {
    String ip = "127.0.0.1";
    String community = "public";
    SnmpData.setPDU(ip, community, "1.3.6.1.2.1.1.6.0","jianghuiwen");
    }


    public void testVersion()
    {
        System.out.println(org.snmp4j.version.VersionInfo.getVersion());
    }
}
文档和源码csdn下载：http://download.csdn.net/detail/davebobo/9509435
ref: http://www.tuicool.com/articles/FF7fEbi
ref: http://blog.chinaunix.net/uid-21857285-id-3340206.html
-------------------------更新--------------------------------------
Trap功能的实现：
下面是两个用于发送和接收Trap报文信息的类:
接收Trap消息类：
[java] view plain copy
import java.io.IOException;
import java.net.UnknownHostException;
import java.util.Vector;

import org.snmp4j.CommandResponder;
import org.snmp4j.CommandResponderEvent;
import org.snmp4j.MessageDispatcherImpl;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.mp.MPv1;
import org.snmp4j.mp.MPv2c;
import org.snmp4j.mp.MPv3;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.TcpAddress;
import org.snmp4j.smi.UdpAddress;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultTcpTransportMapping;
import org.snmp4j.transport.DefaultUdpTransportMapping;
import org.snmp4j.util.MultiThreadedMessageDispatcher;
import org.snmp4j.util.ThreadPool;

/**
* 本类用于监听代理进程的Trap信息
*
* @author zhanjia
*
*/
public class MultiThreadedTrapReceiver implements CommandResponder {

    private MultiThreadedMessageDispatcher dispatcher;
    private Snmp snmp = null;
    private Address listenAddress;
    private ThreadPool threadPool;

    public MultiThreadedTrapReceiver() {
        // BasicConfigurator.configure();
    }

    private void init() throws UnknownHostException, IOException {
        threadPool = ThreadPool.create("Trap", 2);
        dispatcher = new MultiThreadedMessageDispatcher(threadPool,
                new MessageDispatcherImpl());
        listenAddress = GenericAddress.parse(System.getProperty(
                "snmp4j.listenAddress", "udp:192.168.1.23/162")); // 本地IP与监听端口
        TransportMapping transport;
        // 对TCP与UDP协议进行处理
        if (listenAddress instanceof UdpAddress) {
            transport = new DefaultUdpTransportMapping(
                    (UdpAddress) listenAddress);
        } else {
            transport = new DefaultTcpTransportMapping(
                    (TcpAddress) listenAddress);
        }
        snmp = new Snmp(dispatcher, transport);
        snmp.getMessageDispatcher().addMessageProcessingModel(new MPv1());
        snmp.getMessageDispatcher().addMessageProcessingModel(new MPv2c());
        snmp.getMessageDispatcher().addMessageProcessingModel(new MPv3());
        USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(MPv3
                .createLocalEngineID()), 0);
        SecurityModels.getInstance().addSecurityModel(usm);
        snmp.listen();
    }


    public void run() {
        try {
            init();
            snmp.addCommandResponder(this);
            System.out.println("开始监听Trap信息!");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    /**
     * 实现CommandResponder的processPdu方法, 用于处理传入的请求、PDU等信息
     * 当接收到trap时，会自动进入这个方法
     *
     * @param respEvnt
     */
    public void processPdu(CommandResponderEvent respEvnt) {
        // 解析Response
        if (respEvnt != null && respEvnt.getPDU() != null) {
            Vector<VariableBinding> recVBs = respEvnt.getPDU().getVariableBindings();
            for (int i = 0; i < recVBs.size(); i++) {
                VariableBinding recVB = recVBs.elementAt(i);
                System.out.println(recVB.getOid() + " : " + recVB.getVariable());
            }
        }
    }

    public static void main(String[] args) {
        MultiThreadedTrapReceiver multithreadedtrapreceiver = new MultiThreadedTrapReceiver();
        multithreadedtrapreceiver.run();
    }

}
发送Trap消息的类：
[java] view plain copy
import java.io.IOException;
import java.util.Vector;

import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

/**
* 本类用于向管理进程发送Trap信息
*
* @author zhanjia
*
*/
public class SnmpUtilSendTrap {

    private Snmp snmp = null;

    private Address targetAddress = null;

    public void initComm() throws IOException {

        // 设置管理进程的IP和端口
        targetAddress = GenericAddress.parse("udp:192.168.1.23/162");
        TransportMapping transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(transport);
        transport.listen();

    }

    /**
     * 向管理进程发送Trap报文
     *
     * @throws IOException
     */
    public void sendPDU() throws IOException {

        // 设置 target
        CommunityTarget target = new CommunityTarget();
        target.setAddress(targetAddress);

        // 通信不成功时的重试次数
        target.setRetries(2);
        // 超时时间
        target.setTimeout(1500);
        // snmp版本
        target.setVersion(SnmpConstants.version2c);

        // 创建 PDU
        PDU pdu = new PDU();
        pdu.add(new VariableBinding(new OID(".1.3.6.1.2.3377.10.1.1.1.1"),
                new OctetString("SnmpTrap")));
        pdu.add(new VariableBinding(new OID(".1.3.6.1.2.3377.10.1.1.1.2"),
                new OctetString("JavaEE")));
        pdu.setType(PDU.TRAP);

        // 向Agent发送PDU，并接收Response
        ResponseEvent respEvnt = snmp.send(pdu, target);

        // 解析Response
        if (respEvnt != null && respEvnt.getResponse() != null) {
            Vector<VariableBinding> recVBs = respEvnt.getResponse()
            .getVariableBindings();
            for (int i = 0; i < recVBs.size(); i++) {
                VariableBinding recVB = recVBs.elementAt(i);
                System.out.println(recVB.getOid() + " : " + recVB.getVariable());
            }
        }
    }

    public static void main(String[] args) {
        try {
            SnmpUtilSendTrap util = new SnmpUtilSendTrap();
            util.initComm();
            util.sendPDU();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}
1、运行MultiThreadedTrapReceiver类，提示“开始监听Trap信息!”并处理监听状态
2、运行SnmpUtilSendTrap类，运行完毕后，将会在“开始监听Trap信息!”后面显示：
1.3.6.1.2.3377.10.1.1.1.1 : SnmpTrap
1.3.6.1.2.3377.10.1.1.1.2 : JavaEE
MultiThreadedTrapReceiver输出面板中显示以上两行即表示测试成功！
说明：
本例只在本人电脑上测试过，操作系统为Windows
ref:http://www.iteye.com/topic/308836
-----------------------------------------------------更新20160621-------------------------------------------------
接下来问题又来了，我们发的trap消息如果manager掉线我们应该考虑将trap消息保存下来，此时snmp inform就用上场了。详解请看下文：http://blog.csdn.net/davebobo/article/details/51730688
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原文地址：https://www.cnblogs.com/jing1617/p/8780366.html