Getting started with SNMP4J

Question

I need to make an agent in SNMP4J, but the documentation on how to get started is pretty poor. Does anyone have any experience with SNMP4J and could give me an idea on how to get started? Thanks.

Answer 1

You can download the source code for SNMP4JAgent here:

http://www.snmp4j.org/html/download.html

The source code includes a sample agent -- look in the org.snmp4j.agent.example package for all of the related classes.

http://www.snmp4j.org/agent/doc/org/snmp4j/agent/example/SampleAgent.html

One way of getting started would be to create an agent using the example code and then modify it to suit your needs. The JavaDoc describing each of the classes is a bit terse, but it's complete.

Answer 2

Good documentation of SNMPv3 implementation using SNMP4j libraries is really hard to find. There are no working examples of SNMPv3 agents in the official documentation. I wrote a basic SNMP Agent that can connect using SNMPv3 protocol, and perform GET and SET operations on the server.

import java.io.IOException;

import org.snmp4j.PDU;
import org.snmp4j.ScopedPDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.UserTarget;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.MPv3;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.security.AuthGeneric;
import org.snmp4j.security.AuthSHA;
import org.snmp4j.security.PrivAES128;
import org.snmp4j.security.PrivacyGeneric;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.security.UsmUser;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.TransportIpAddress;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultTcpTransportMapping;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class SNMPV3Agent {

    private Address nmsIP;
    private String user;
    private String securityName;
    private String privacyPassword;
    private String authorizationPassword;
    private AuthGeneric authProtocol;
    private PrivacyGeneric privacyProtocol;
    private String protocol;

    private long timeOut = 1000L;
    private int noOfRetries = 2;

    private Snmp snmp;
    private UserTarget target;

    SNMPV3Agent(String ip, String protocol, int snmpPort, String username,
            String securityName, String privacyPassword, String authPassowrd,
            AuthGeneric authProtocol, PrivacyGeneric privacyProtocol) {

        nmsIP = GenericAddress.parse(protocol + ":" + ip + "/" + snmpPort);
        System.out.println("NMS IP set : " + nmsIP.toString());

        this.protocol = protocol;
        this.user = username;
        this.securityName = securityName;
        this.privacyPassword = privacyPassword;
        this.authorizationPassword = authPassowrd;
        this.authProtocol = authProtocol;
        this.privacyProtocol = privacyProtocol;

    }

    public static void main(String[] args) {

        SNMPV3Agent agent = new SNMPV3Agent("nms/server-ip", "udp", 162,
                "abhinav", "abhinav", "myprivpass", "myauthpass",
                new AuthSHA(), new PrivAES128());
        try {
            agent.startAgent();
            ResponseEvent response = agent
                    .snmpGetOperation(SnmpConstants.sysName);
            System.out.println(response.getResponse());
            // Similarly you can perform set operation.
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void startAgent() throws IOException {
        if (snmp == null) {
            TransportMapping<? extends TransportIpAddress> transport = null;
            if (protocol.equalsIgnoreCase("udp")) {
                System.out.println("UDP Protocol selected.");
                transport = new DefaultUdpTransportMapping();
            } else {
                System.out.println("TCP Protocol selected.");
                transport = new DefaultTcpTransportMapping();
            }
            snmp = new Snmp(transport);
            USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(
                    MPv3.createLocalEngineID()), 0);
            SecurityModels.getInstance().addSecurityModel(usm);
            transport.listen();
            snmp.getUSM().addUser(
                    new OctetString(user),
                    new UsmUser(new OctetString(securityName), authProtocol
                            .getID(), new OctetString(authorizationPassword),
                            privacyProtocol.getID(), new OctetString(
                                    privacyPassword)));

            target = createUserTarget();
        }

    }

    public ResponseEvent snmpSetOperation(VariableBinding[] vars)
            throws IOException {
        PDU setPdu = new ScopedPDU();
        for (VariableBinding variableBinding : vars) {
            setPdu.add(variableBinding);
        }
        return snmp.send(setPdu, target);
    }

    public ResponseEvent snmpGetOperation(OID oid) throws IOException {

        PDU getPdu = new ScopedPDU();
        getPdu.add(new VariableBinding(oid));
        return snmp.get(getPdu, target);
    }

    private UserTarget createUserTarget() {
        UserTarget target = new UserTarget();
        target.setAddress(nmsIP);
        target.setRetries(noOfRetries);
        target.setTimeout(timeOut);
        target.setVersion(3);
        target.setSecurityLevel(3);
        target.setSecurityName(new OctetString(securityName));
        return target;
    }

    public long getTimeOut() {
        return timeOut;
    }

    public void setTimeOut(long timeOut) {
        this.timeOut = timeOut;
    }

    public int getNoOfRetries() {
        return noOfRetries;
    }

    public void setNoOfRetries(int noOfRetries) {
        this.noOfRetries = noOfRetries;
    }
}

Adding other operations such as GETBulk will be relatively easy once you understand how GET and SET works. Let me know if you need more clarifications in the comments.

Answer 3

Here is a great link that describes the snmp class which is the core of snmp4j

http://www.snmp4j.org/doc/org/snmp4j/package-summary.html

Also take a look at the SnmpRequest.java for a quick example