### SNMP Walk Command Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

This is an example of how to use the snmpwalk command-line tool to query SNMP data from localhost.

```bash
snmpwalk -v 2c -c public localhost 1.3.6.1
```

--------------------------------

### GetBulkRequest-PDU Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3416.txt

An example of a GetBulkRequest-PDU with specified non-repeaters and max-repetitions parameters.

```text
    GetBulkRequest [ non-repeaters = 1, max-repetitions = 2 ]
                  ( sysUpTime,
                    ipNetToMediaPhysAddress,
                    ipNetToMediaType )
```

--------------------------------

### Install node-net-snmp

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Install the node-net-snmp module using npm. This is the first step before requiring it in your project.

```bash
npm install net-snmp
```

--------------------------------

### Table Data Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Shows the hierarchical structure of an SNMP table, including the table itself, its entry, columns, and rows. This example uses a portion of the ifTable.

```text
1.3.6.1.2.1.2.2   <= ifTable (table)
1.3.6.1.2.1.2.2.1   <= ifEntry (table entry)
1.3.6.1.2.1.2.2.1.1   <= ifIndex (column 1)
1.3.6.1.2.1.2.2.1.1.1 = Integer: 1   <= ifIndex row 1 value = 1
1.3.6.1.2.1.2.2.1.1.2 = Integer: 2   <= ifIndex row 2 value = 2
```

--------------------------------

### Clone and configure repository

Source: https://github.com/markabrahams/node-net-snmp/blob/master/CONTRIBUTING.md

Initial setup for a local development environment by cloning a fork and adding the upstream remote.

```bash
# Clone your fork of the repo into the current directory
git clone https://github.com/<your-username>/node-net-snmp
# Navigate to the newly cloned directory
cd node-net-snmp
# Assign the original repo to a remote called "upstream"
git remote add upstream https://github.com/markabrahams/node-net-snmp
```

--------------------------------

### Response-PDU Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3416.txt

The corresponding Response-PDU generated by the command responder application.

```text
    Response (( sysUpTime.0 =  "123456" ),
               ( ipNetToMediaPhysAddress.1.9.2.3.4 = "000010543210" ),
            ( ipNetToMediaType.1.9.2.3.4 =  "dynamic" ),
               ( ipNetToMediaPhysAddress.1.10.0.0.51 = "000010012345" ),
            ( ipNetToMediaType.1.10.0.0.51 =  "static" ))
```

--------------------------------

### SNMP Response-PDU Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3416.txt

Illustrates a typical SNMP Response-PDU with variable bindings indicating the end of a table.

```text
Response (( sysUpTime.0 =  "123466" ),
               ( ipNetToMediaPhysAddress.2.10.0.0.15 = "000010987654" ),
               ( ipNetToMediaType.2.10.0.0.15 = "dynamic" ),
               ( ipNetToMediaNetAddress.1.9.2.3.4 = "9.2.3.4" ),
            ( ipRoutingDiscards.0 =  "2" ))
```

--------------------------------

### Creating an Agent with Simple Access Control

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Instantiate an Agent with the Simple Access Control Model. This example demonstrates adding communities and users, then setting their access levels.

```javascript
var agent = snmp.createAgent({
    accessControlModelType: snmp.AccessControlModelType.Simple
}, function (error, data) {
    // null callback for example brevity
});
var authorizer = agent.getAuthorizer ();
authorizer.addCommunity ("public");
authorizer.addCommunity ("private");
authorizer.addUser ({
    name: "fred",
    level: snmp.SecurityLevel.noAuthNoPriv
});
var acm = authorizer.getAccessControlModel ();
// Since read-only is the default, explicitly setting read-only access is not required - just shown here as an example
acm.setCommunityAccess ("public", snmp.AccessLevel.ReadOnly);
acm.setCommunityAccess ("private", snmp.AccessLevel.ReadWrite);
acm.setUserAccess ("fred", snmp.AccessLevel.ReadWrite);
```

--------------------------------

### Send Generic Cold-Start Inform with session.inform

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Send a generic cold-start SNMP inform message to a remote host using session.inform. This example does not include custom varbinds.

```js
session.inform (snmp.TrapType.ColdStart, function (error) {
    if (error)
        console.error (error);
});
```

--------------------------------

### Example Table Structure

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Illustrates the expected object structure for fetched table data, keyed by row index and then by column number.

```javascript
var table = {
    // Rows keyed by ifIndex (1 and 2 are shown)
    1: {
        // ifDescr (column 2) and ifType (columnd 3) are shown
        2: "interface-1",
        3: 6,
        ...
    },
    2: {
        2: "interface-2",
        3: 6,
        ...
    },
    ...
}
```

--------------------------------

### Legal SMIv2 Sub-typing Examples

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v2c/rfc2578.txt

Valid syntax for applying range and size constraints to Integer32, OCTET STRING, and other types.

```SMIv2
Integer32 (-20..100)
Integer32 (0..100 | 300..500)
Integer32 (300..500 | 0..100)
Integer32 (0 | 2 | 4 | 6 | 8 | 10)
OCTET STRING (SIZE(0..100))
OCTET STRING (SIZE(0..100 | 300..500))
OCTET STRING (SIZE(0 | 2 | 4 | 6 | 8 | 10))
SYNTAX   TimeInterval (0..100)
SYNTAX   DisplayString (SIZE(0..32))
```

--------------------------------

### SNMP SetRequest-PDU 'tooBig' Response Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3416.txt

Shows the structure of an alternate Response-PDU generated when a SetRequest-PDU would result in a message exceeding size constraints.

```text
Response-PDU having the same values in its request-id and variable-bindings fields as the received SetRequest-PDU, and the largest possible sizes of the error-status and error-index fields. If the determined message size is greater than either a local constraint or the maximum message size of the originator, then an alternate Response-PDU is generated, transmitted to the originator of the SetRequest-PDU, and processing of the SetRequest-PDU terminates immediately thereafter. This alternate Response-PDU is formatted with the same values in its request-id field as the received SetRequest-PDU, with the value of its error-status field set to "tooBig", the value of its error-index field set to zero, and an empty variable-bindings field.
```

--------------------------------

### SNMP GetResponse PDU Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1098.txt

Illustrates a GetResponse PDU containing route information. This is typically sent by an SNMP agent in response to a GetRequest.

```text
GetResponse (( ipRouteDest.9.1.2.3 =  "9.1.2.3" ),
                         ( ipRouteNextHop.9.1.2.3 = "99.0.0.3" ),
                         ( ipRouteMetric1.9.1.2.3 = 3 ))
```

```text
GetResponse (( ipRouteDest.10.0.0.51 = "10.0.0.51" ),
                         ( ipRouteNextHop.10.0.0.51 = "89.1.1.42" ),
                         ( ipRouteMetric1.10.0.0.51 = 5 ))
```

```text
GetResponse (( ipRouteDest.10.0.0.99 = "10.0.0.99" ),
                         ( ipRouteNextHop.10.0.0.99 = "89.1.1.42" ),
                         ( ipRouteMetric1.10.0.0.99 = 5 ))
```

--------------------------------

### SNMP Notification Structure Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Illustrates the structure of a notification object received by the callback function, including PDU details and sender information.

```json
{
    "pdu": {
        "type": 166,
        "id": 45385686,
        "varbinds": [
            {
                "oid": "1.3.6.1.2.1.1.3.0",
                "type": 67,
                "value": 5
            },
            {
                "oid": "1.3.6.1.6.3.1.1.4.1.0",
                "type": 6,
                "value": "1.3.6.1.6.3.1.1.5.2"
            }
        ],
        "scoped": false
    },
    "rinfo": {
        "address": "127.0.0.1",
        "family": "IPv4",
        "port": 43162,
        "size": 72
    }
}
```

--------------------------------

### Simple OID String Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

This demonstrates how to represent a simple Object Identifier (OID) as a string. This format is accepted by some parts of the module for specifying OIDs.

```javascript
var oid = "1.3.6.1.2.1.1.5.0";
```

--------------------------------

### String Size Constraint Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Limits the length of strings using an array of min/max size range objects, similar to integer ranges.

```javascript
constraints: {
    sizes: [
        { min: 1, max: 3 },
        { min: 5 }
    ]
}
```

--------------------------------

### SNMP GetNextRequest PDU Example

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1098.txt

Shows a GetNextRequest PDU used to retrieve the next sequential variable binding. This is often used for table traversal.

```text
GetNextRequest ( ipRouteDest.9.1.2.3,
                         ipRouteNextHop.9.1.2.3,
                         ipRouteMetric1.9.1.2.3 )
```

```text
GetNextRequest ( ipRouteDest.10.0.0.51,
                         ipRouteNextHop.10.0.0.51,
                         ipRouteMetric1.10.0.0.51 )
```

```text
GetNextRequest ( ipRouteDest.10.0.0.99,
                         ipRouteNextHop.10.0.0.99,
                         ipRouteMetric1.10.0.0.99 )
```

--------------------------------

### SNMPv1 Error Handling in Callback

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Example of handling a GET request in SNMPv1. Assumes varbinds will have values if no error object is passed to the callback.

```javascript
var oids = ["1.3.6.1.2.1.1.5.0", "1.3.6.1.2.1.1.6.0"];

session.get (oids, function (error, varbinds) {
    if (error) {
        console.error (error.toString ());
    } else {
        var sysName = varbinds[0].value; // this WILL have a value
    }
});
```

--------------------------------

### Create Module Store with Custom Base Modules

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Demonstrates creating a ModuleStore instance and specifying a custom list of base modules to load, which can help avoid type overrides.

```javascript
// Example of selecting only SNMPv2 MIBs
const store = snmp.createModuleStore({
  baseModules: [
    'SNMPv2-SMI',
    'SNMPv2-CONF',
    'SNMPv2-TC',
    'SNMPv2-MIB',
  ],
});
```

--------------------------------

### Perform SNMP GET Request

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Create an SNMP session to a remote host and perform a GET request for specified OIDs. Handles errors and prints results.

```javascript
var session = snmp.createSession ("127.0.0.1", "public");

var oids = ["1.3.6.1.2.1.1.5.0", "1.3.6.1.2.1.1.6.0"];

session.get (oids, function (error, varbinds) {
    if (error) {
        console.error (error);
    } else {
        for (var i = 0; i < varbinds.length; i++) {
            if (snmp.isVarbindError (varbinds[i])) {
                console.error (snmp.varbindError (varbinds[i]));
            } else {
                console.log (varbinds[i].oid + " = " + varbinds[i].value);
            }
        }
    }
    session.close ();
});
```

--------------------------------

### Load MIB, Create Agent, and Manipulate MIB Values

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

This snippet demonstrates creating a module store, loading a MIB file, fetching its JSON representation, and then creating an agent to register MIB providers and manipulate scalar values and table rows.

```javascript
var store = snmp.createModuleStore ();
store.loadFromFile ("/path/to/your/mibs/SNMPv2-MIB.mib");
var jsonModule = store.getModule ("SNMPv2-MIB");

// Fetch MIB providers, create an agent, and register the providers with your agent
var providers = store.getProvidersForModule ("SNMPv2-MIB");
// Not recommended - but authorization and callback turned off for example brevity
var agent = snmp.createAgent ({disableAuthorization: true}, function (error, data) {});
var mib = agent.getMib ();
mib.registerProviders (providers);

// Start manipulating the MIB through the registered providers using the `Mib` API calls
mib.setScalarValue ("sysDescr", "The most powerful system you can think of");
mib.setScalarValue ("sysName", "multiplied-by-six");
mib.addTableRow ("sysOREntry", [1, "1.3.6.1.4.1.47491.42.43.44.45", "I've dreamed up this MIB", 20]);
```

--------------------------------

### Example MIB Object Definitions

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1065.txt

Illustrative definitions of MIB object types using the OBJECT-TYPE macro, including syntax, access, status, and OBJECT IDENTIFIER assignments. These examples show how to formally define managed objects like atIndex and atEntry.

```ASN.1
atIndex OBJECT-TYPE

          SYNTAX  INTEGER
          ACCESS  read-write
          STATUS  mandatory
          ::= { atEntry 1 }
```

```ASN.1
atPhysAddress OBJECT-TYPE
          SYNTAX  OCTET STRING
          ACCESS  read-write
          STATUS  mandatory
          ::= { atEntry 2 }
```

```ASN.1
atNetAddress OBJECT-TYPE
          SYNTAX  NetworkAddress
          ACCESS  read-write
          STATUS  mandatory
          ::= { atEntry 3 }
```

```ASN.1
atEntry OBJECT-TYPE
          SYNTAX  AtEntry
          ACCESS  read-write
          STATUS  mandatory
          ::= { atTable 1 }
```

```ASN.1
atTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF AtEntry
          ACCESS  read-write
          STATUS  mandatory
          ::= { at 1 }
```

--------------------------------

### Fetch and Display ifTable

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Demonstrates fetching the ifTable using session.table and processing the response to print rows in a sorted order. Includes helper functions for numerical sorting.

```javascript
var oid = "1.3.6.1.2.1.2.2";

function sortInt (a, b) {
    if (a > b)
        return 1;
    else if (b > a)
        return -1;
    else
        return 0;
}

function responseCb (error, table) {
    if (error) {
        console.error (error.toString ());
    } else {
        // This code is purely used to print rows out in index order,
        // ifIndex's are integers so we'll sort them numerically using
        // the sortInt() function above
        var indexes = [];
        for (index in table)
            indexes.push (parseInt (index));
        indexes.sort (sortInt);
        
        // Use the sorted indexes we've calculated to walk through each
        // row in order
        for (var i = 0; i < indexes.length; i++) {
            // Like indexes we sort by column, so use the same trick here,
            // some rows may not have the same columns as other rows, so
            // we calculate this per row
            var columns = [];
            for (column in table[indexes[i]])
                columns.push (parseInt (column));
            columns.sort (sortInt);
            
            // Print index, then each column indented under the index
            console.log ("row for index = " + indexes[i]);
            for (var j = 0; j < columns.length; j++) {
                console.log ("   column " + columns[j] + " = "
                        + table[indexes[i]][columns[j]]);
            }
        }
    }
}

var maxRepetitions = 20;

// The maxRepetitions argument is optional, and will be ignored unless using
// SNMP verison 2c
session.table (oid, maxRepetitions, responseCb);
```

--------------------------------

### GET ifDescr

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the description string for a specific network interface.

```APIDOC
## GET ifDescr

### Description
A text string containing information about the interface, including manufacturer, product name, and hardware version.

### Method
GET

### Endpoint
ifEntry.ifDescr

### Response
#### Success Response (200)
- **ifDescr** (OCTET STRING) - Human-readable description of the interface.
```

--------------------------------

### forwarder.dumpProxies

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Prints a console dump of all defined proxy configurations.

```APIDOC
## forwarder.dumpProxies ()

### Description
Prints a dump of all proxy definitions to the console for inspection.
```

--------------------------------

### GET ifIndex

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the unique index for a specific network interface.

```APIDOC
## GET ifIndex

### Description
A unique value for each interface. Its value ranges between 1 and the value of ifNumber.

### Method
GET

### Endpoint
ifEntry.ifIndex

### Response
#### Success Response (200)
- **ifIndex** (INTEGER) - Unique identifier for the interface.
```

--------------------------------

### GET ifNumber

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the total number of network interfaces on the system.

```APIDOC
## GET ifNumber

### Description
The number of network interfaces (regardless of their current state) on which this system can send/receive IP datagrams.

### Method
GET

### Endpoint
interfaces.ifNumber

### Response
#### Success Response (200)
- **ifNumber** (INTEGER) - The count of network interfaces.
```

--------------------------------

### GET GetNextRequest-PDU

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1067.txt

Defines the structure of the GetNextRequest-PDU, which is identical to the GetRequest-PDU structure.

```APIDOC
## GET GetNextRequest-PDU

### Description
The GetNextRequest-PDU is used to retrieve the value of the next object in the MIB tree relative to the provided variable names.

### Request Body
- **request-id** (RequestID) - Required - Unique identifier for the request.
- **error-status** (ErrorStatus) - Required - Always 0 for requests.
- **error-index** (ErrorIndex) - Required - Always 0 for requests.
- **variable-bindings** (VarBindList) - Required - List of variable names to retrieve the next instance for.

### Request Example
{
  "request-id": 12346,
  "error-status": 0,
  "error-index": 0,
  "variable-bindings": [{"name": "sysDescr", "value": null}]
}
```

--------------------------------

### Create a topic branch

Source: https://github.com/markabrahams/node-net-snmp/blob/master/CONTRIBUTING.md

Initializes a new branch for specific features or fixes.

```bash
git checkout -b <topic-branch-name>
```

--------------------------------

### Get Authorizer Instance

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Obtain the singleton Authorizer instance for a receiver or agent.

```javascript
receiver.getAuthorizer ().getCommunities ();
```

--------------------------------

### SNMPv3 USM msgSecurityParameters with Sample Values

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3414.txt

An example of msgSecurityParameters with concrete hexadecimal values, illustrating the encoding of various parameters including engine ID, boots, time, username, and sample digest/salt values.

```text
04 39           OCTET STRING,                  length 57
30 37           SEQUENCE,                      length 55
04 0c 80000002  msgAuthoritativeEngineID:      IBM
      01                                       IPv4 address
      09840301                                 9.132.3.1
02 01 01        msgAuthoritativeEngineBoots:   1
02 02 0101      msgAuthoritativeEngineTime:    257
04 04 62657274  msgUserName:                   bert
04 0c 01234567  msgAuthenticationParameters:   sample value
      89abcdef
      fedcba98
04 08 01234567  msgPrivacyParameters:          sample value
      89abcdef
```

--------------------------------

### Reference Simple Object

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1155.txt

Example of referencing a simple object type within a table.

```text
{ atPhysAddress }
```

--------------------------------

### SNMPv3 USM User Table Creation Procedure

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3414.txt

Outlines the recommended procedure for creating a new user entry in the usmUserTable, involving the use of usmUserSpinLock and setting various user parameters like privacy and authentication protocols.

```text
usmUserTable     OBJECT-TYPE
    SYNTAX       SEQUENCE OF UsmUserEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION "The table of users configured in the SNMP engine's
                 Local Configuration Datastore (LCD).

                 To create a new user (i.e., to instantiate a new
                 conceptual row in this table), it is recommended to
                 follow this procedure:

                   1)  GET(usmUserSpinLock.0) and save in sValue.


                   2)  SET(usmUserSpinLock.0=sValue,
                           usmUserCloneFrom=templateUser,
                           usmUserStatus=createAndWait)
                       You should use a template user to clone from
                       which has the proper auth/priv protocol defined.

                 If the new user is to use privacy:

                   3)  generate the keyChange value based on the secret
                       privKey of the clone-from user and the secret key
                       to be used for the new user. Let us call this
                       pkcValue.
                   4)  GET(usmUserSpinLock.0) and save in sValue.
                   5)  SET(usmUserSpinLock.0=sValue,
                           usmUserPrivKeyChange=pkcValue
                           usmUserPublic=randomValue1)
                   6)  GET(usmUserPulic) and check it has randomValue1.
                       If not, repeat steps 4-6.

                 If the new user will never use privacy:

                   7)  SET(usmUserPrivProtocol=usmNoPrivProtocol)

                 If the new user is to use authentication:

                   8)  generate the keyChange value based on the secret
                       authKey of the clone-from user and the secret key
                       to be used for the new user. Let us call this
                       akcValue.
                   9)  GET(usmUserSpinLock.0) and save in sValue.
                   10) SET(usmUserSpinLock.0=sValue,
                           usmUserAuthKeyChange=akcValue
                           usmUserPublic=randomValue2)
                   11) GET(usmUserPulic) and check it has randomValue2.
                       If not, repeat steps 9-11.

                 If the new user will never use authentication:

                   12) SET(usmUserAuthProtocol=usmNoAuthProtocol)

                 Finally, activate the new user:

                   13) SET(usmUserStatus=active)

                 The new user should now be available and ready to be
                 used for SNMPv3 communication. Note however that access
                 to MIB data must be provided via configuration of the
                 SNMP-VIEW-BASED-ACM-MIB.
```

--------------------------------

### GET sysObjectID

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the vendor's authoritative identification of the network management subsystem.

```APIDOC
## GET sysObjectID

### Description
The vendor's authoritative identification of the network management subsystem contained in the entity. This value is allocated within the SMI enterprises subtree (1.3.6.1.4.1).

### Method
GET

### Endpoint
system.2

### Parameters
- **Access** (read-only) - Mandatory
- **Status** (mandatory) - Mandatory

### Response
#### Success Response (200)
- **sysObjectID** (OBJECT IDENTIFIER) - The unique identifier for the managed device type.
```

--------------------------------

### GET GetRequest-PDU

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1067.txt

Defines the structure of the GetRequest-PDU used to retrieve managed object values.

```APIDOC
## GET GetRequest-PDU

### Description
The GetRequest-PDU is used by a protocol entity to request the values of specific managed objects.

### Request Body
- **request-id** (RequestID) - Required - Unique identifier for the request.
- **error-status** (ErrorStatus) - Required - Always 0 for requests.
- **error-index** (ErrorIndex) - Required - Always 0 for requests.
- **variable-bindings** (VarBindList) - Required - List of variable names to retrieve.

### Request Example
{
  "request-id": 12345,
  "error-status": 0,
  "error-index": 0,
  "variable-bindings": [{"name": "sysDescr.0", "value": null}]
}
```

--------------------------------

### Require node-net-snmp Module

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Load the installed node-net-snmp module into your project using the require() function.

```javascript
var snmp = require ("net-snmp");
```

--------------------------------

### Test Proxy Access via Net-SNMP CLI

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Demonstrates how to test the configured proxy using the Net-SNMP command-line tools. This command targets the local agent with a specific context, which should then be forwarded to the configured remote host.

```bash
snmpget -v 3 -u fred -l noAuthNoPriv -n slatescontext localhost 1.3.6.1.2.1.1.1.0
```

--------------------------------

### Create SNMP Agent with Default Options

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Instantiates an SNMP agent using default options and a callback function for handling errors and data. Ensure to provide valid options and a callback.

```javascript
// Default options
var options = {
    port: 161,
    disableAuthorization: false,
    accessControlModelType: snmp.AccessControlModelType.None,
    engineID: "8000B98380XXXXXXXXXXXXXXXXXXXXXXXX", // where the X's are random hex digits
    address: null,
    transport: "udp4",
    mibOptions: {}
};

var callback = function (error, data) {
    if ( error ) {
        console.error (error);
    } else {
        console.log (JSON.stringify(data, null, 2));
    }
};

agent = snmp.createAgent (options, callback);
```

--------------------------------

### GET ipAddrTable

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the table of addressing information relevant to the entity's IP addresses.

```APIDOC
## GET ipAddrTable

### Description
The table of addressing information relevant to this entity's IP addresses.

### Method
GET

### Endpoint
ipAddrTable { ip 20 }

### Response
#### Success Response (200)
- **ipAdEntAddr** (IpAddress) - The IP address to which this entry's addressing information pertains.
- **ipAdEntIfIndex** (INTEGER) - The index value which uniquely identifies the interface.
- **ipAdEntNetMask** (IpAddress) - The subnet mask associated with the IP address.
- **ipAdEntBcastAddr** (INTEGER) - The value of the least-significant bit in the IP broadcast address.
```

--------------------------------

### GET sysUpTime

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1066.txt

Retrieves the time since the network management portion of the system was last re-initialized.

```APIDOC
## GET sysUpTime

### Description
The time (in hundredths of a second) since the network management portion of the system was last re-initialized.

### Method
GET

### Endpoint
system.sysUpTime

### Response
#### Success Response (200)
- **sysUpTime** (TimeTicks) - The time in hundredths of a second since last re-initialization.
```

--------------------------------

### Create SNMPv3 Session with Options

Source: https://github.com/markabrahams/node-net-snmp/blob/master/README.md

Instantiates an SNMPv3 session with default or custom options. Ensure `engineID` is correctly formatted with random hex digits.

```javascript
// Default options for v3
var options = {
    port: 161,
    retries: 1,
    timeout: 5000,
    transport: "udp4",
    trapPort: 162,
    version: snmp.Version3,
    engineID: "8000B98380XXXXXXXXXXXXXXXXXXXXXXXX", // where the X's are random hex digits
    backwardsGetNexts: true,
    reportOidMismatchErrors: false,
    idBitsSize: 32,
    context: "",
    strictIntRangeChecks: false
};

// Example user
var user = {
    name: "blinkybill",
    level: snmp.SecurityLevel.authPriv,
    authProtocol: snmp.AuthProtocols.sha,
    authKey: "madeahash",
    privProtocol: snmp.PrivProtocols.des,
    privKey: "privycouncil"
};

var session = snmp.createV3Session ("127.0.0.1", user, options);
```

--------------------------------

### GET /usmStats

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3414.txt

Retrieves various SNMP engine statistics related to packet drops and security errors.

```APIDOC
## GET /usmStats

### Description
Retrieves counters for packets dropped by the SNMP engine due to various security failures.

### Method
GET

### Endpoint
/usmStats

### Response
#### Success Response (200)
- **usmStatsUnknownEngineIDs** (Counter32) - Packets dropped due to unknown snmpEngineID.
- **usmStatsWrongDigests** (Counter32) - Packets dropped due to incorrect digest values.
- **usmStatsDecryptionErrors** (Counter32) - Packets dropped due to decryption failures.
```

--------------------------------

### MIB Object Definitions

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v1/rfc1155.txt

Examples of MIB object definitions including atIndex, atPhysAddress, atNetAddress, atEntry, and atTable.

```APIDOC
## MIB Object Definitions

### Description
Definitions for address translation table objects.

### Object Definitions
- **atIndex**: INTEGER, read-write, mandatory, { atEntry 1 }
- **atPhysAddress**: OCTET STRING, read-write, mandatory, { atEntry 2 }
- **atNetAddress**: NetworkAddress, read-write, mandatory, { atEntry 3 }
- **atEntry**: AtEntry, read-write, mandatory, { atTable 1 }
- **atTable**: SEQUENCE OF AtEntry, read-write, mandatory, { at 1 }

### AtEntry Structure
```
AtEntry ::= SEQUENCE {
    atIndex INTEGER,
    atPhysAddress OCTET STRING,
    atNetAddress NetworkAddress
}
```
```

--------------------------------

### SNMPv3 USM keyChange Result using MD5

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3414.txt

Sample keyChange result using MD5, showing the calculated new key, localized key, and the final value to be sent for keyChange, based on a given password and engineID.

```text
'00 00 00 00 00 00 00 00 00 00 00 02'H

'01 ad d2 73 10 7c 4e 59 6b 4b 00 f8 2b 1d 42 a7'H

'87 02 1d 7b d9 d1 01 ba 05 ea 6e 3b f9 d9 bd 4a'H

'00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00'

'00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
88 05 61 51 41 67 6c c9 19 61 74 e7 42 a3 25 51'H
```

--------------------------------

### Password to Key Sample Code for MD5

Source: https://github.com/markabrahams/node-net-snmp/blob/master/ref/rfc/v3/rfc3414.txt

This C code snippet demonstrates the password to key algorithm using MD5, as specified in RFC 1321. It takes a password, engineID, and their lengths as input to generate a 16-octet key.

```c
void password_to_key_md5(
   u_char *password,    /* IN */
   u_int   passwordlen, /* IN */
   u_char *engineID,    /* IN  - pointer to snmpEngineID  */
   u_int   engineLength,/* IN  - length of snmpEngineID */
   u_char *key)         /* OUT - pointer to caller 16-octet buffer */
{
   MD5_CTX     MD;
   u_char     *cp, password_buf[64];
   u_long      password_index = 0;
   u_long      count = 0, i;

   MD5Init (&MD);   /* initialize MD5 */

   /**********************************************/

```