Using the SNMP plugin

In OpenAF there are two main SNMP plugins: SNMP and SNMP server. In this article we are going to focus on the SNMP plugin that provide SNMP client functionality.

SNMP has different versions (e.g. 1, 2, 3) that require different settings. Starting with version 1 and 2 all you need is the SNMP connection details and, optinionally, a community:

plugin("SNMP");
var snmp = new SNMP("udp:demo.snmplabs.com/161", "public");  // version 1/2

Checking an OID value

To get the value associated with an OID:

snmp.get("1.3.6.1.2.1.1.3.0");
// {
//  "1.3.6.1.2.1.1.3.0": "36 days, 12:34:56.51"
//}

Sending a trap/inform

To send a trap simply:

snmp.trap("1.3.6.1.4.1.20408.4.1.1.2", [
    { OID: "1.2.3.4.5.6.7.8", type: "s", value: "My error message." }
])

You just need to provide the trap OID and an array of OID based values. Each value can have a different type. The supported types are:

Type	Description
i	Integer
u	Unsigned
c	Counter32
s	String
x	Hex String
d	Decimal String
n	A null object
o	An object id
t	Timeticks
a	An ip address

To inform it's exactly the same but it will return you a Java response object:

var response = snmp.inform("1.3.6.1.4.1.20408.4.1.1.2", [
    { OID: "1.2.3.4.5.6.7.8", type: "s", value: "My error message." }
])

In contrast sending a trap will return immediately and there won't be any acknowledgement.

Version 3

On version 3 you need to provide a little more information:

plugin("SNMP");
var aTimeout = 3000, aNumberOfRetries = 3;
var snmp = new SNMP("udp:demo.snmplabs.com/161", "public", aTimeout, aNumberOfRetries, 3, {
    engineId      : "8000000001020304",
    authPassphrase: "authKey1",
    privPassphrase: "privKey1",
    authProtocol  : "MD5",
    privProtocol  : "DES",
    securityName  : "usr-md5-des"
})

But all the rest is same as shown previously.