When this object is created, it starts an SNMP process that handles some standard SNMP MIBs such as system uptime. Prior to starting the SNMP agent, you can register other OIDs for handling. You can set and retrieve these by both an SNMP client and the script.
OID values are retrieved by an SNMP client without script interaction. Setting OID values will generate an roSnmpEvent object stating that they have been changed. The script event handler can then retrieve new values and take appropriate action.
Setting an OID value from an SNMP client doesn't block the client waiting on any script action; there is a short, but indeterminate, time delay for scripts to act on a value change. This isn't a problem generally because of the way SNMP MIBs are designed. If you want to provide constantly updating OID values, you can update them using either a timer or state changes.
The JavaScript equivalent is net-snmp.
The roSnmpAgent object is created with an optional roAssociativeArray:
agent = CreateObject("roSnmpAgent")
As of BrightSignOS 8.3.20, the default parameters below can be provided on object construction. Note that when both ro_community and rw_community are set, they must be unique values. Otherwise, simply provide rw_community:
ifSnmpAgent
AddOidHandler(oid_string As String, writable_flag As Boolean, initial_value As Object) As Boolean
Adds an OID handler with the following parameters to the SNMP agent:
oid_string: The OID string (e.g. "1.3.6.1.4.1.26095.1.1.1.4.4.0"). All OID strings should be numerical.
writable_flag: A Boolean value indicating whether the value can be changed by an SNMP client.
initial_value: The initial value, which can be either an roString or roInt. The OID will reflect the type chosen here.
GetOidValue(oid_string As String) As Object
Returns the current value (as either roString or roInt) for a given OID.
SetOidValue(oid_string As String, new_value As Object) As Boolean
Changes the current value for a given OID. The passed value can be either an roString or roInt.
Start() As Boolean
Starts the SNMP agent. Call this method once all OID handlers have been registered.
Example
agent = CreateObject("roSnmpAgent")
agent.AddOidHandler("1.3.6.1.4.1.26095.1.1.1.4.4.0", false, "ValueOfOid")
agent.AddOidHandler("1.3.6.1.4.1.26095.1.1.1.4.5.0", true, 10)
agent.Start()
ifUserData
SetUserData(user_data As Object)
Sets the user data that will be returned when events are raised.
GetUserData() As Object
Returns the user data that has previously been set via SetUserData(). It will return Invalid if no data has been set.
ifMessagePort
SetPort(port As roMessagePort)
Posts messages of type roSnmpEvent to the attached message port.