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Initialisation

References

Resources

Prerequisites

  • Each message transferred by SNMP has to be assigned a respective OID that is an extension to the SOS assigned OID
    • OIDs used for a product such as JobScheduler, YADE would be assigned a product extension.
    • For a specific product the OID is further extended for use by messages for that product.
  • OIDs of all SOS products are collected into one MIB.

Component Architecture

Implementation

Prerequisites

  • Implementation for SNMPv3
  • No previous versions are supported

SNMP Messages

SNMP Message Types

SNMP MessageFrom / ToMessage Description

Get

Manager / Agent

Accesses and retrieves the current value of one or more MIB objects on an SNMP agent.

GetResponse

Agent / Manager

Replies to a GetGetNext, or Set operation.

GetNext

Manager / Agent

Browses the entire tree of MIB objects, reading the values of variables in the MIB sequentially. Typically, you use GetNext to obtain information from selected columns from one or more rows of a table. GetNext is especially useful for browsing dynamic tables, such as an internal IP route table or an ARP table, reading through the table one row at a time.

GetBulk

 

Manager / Agent

Retrieves data in units as large as possible within the given constraints on the message size. GetBulk, which accesses multiple values at one time without using a GetNext message, minimizes the number of protocol exchanges required to retrieve a large amount of information.

Set

Manager / Agent

Changes the current value of a MIB object. In order to update a MIB value on the SNMP agent, the SNMP manager must have write access to the object. Set is used infrequently, because most MIB objects are read-only by default, so that unauthorized changes cannot be made.

Trap

Agent / Manager

Notifies the specified SNMP manager (the trap destination) when an unexpected event occurs locally on the managed host. You can use traps for limited security checking (such as notifying the trap destination if the agent receives an information request from an SNMP manager that it does not recognize) or for troubleshooting (such as notifying the trap destination if the WINS service fails).

  • Addiitional message types are used for acknowledgement:
SNMP MessageFrom / ToMessage Description

Inform

Manager / Agent

This command is similar to the Trap initiated by the Agent, additionally Inform includes confirmation from the SNMP Manager on receiving the message

ResponseAgent / ManagerIt is the command used to carry back the value(s) or signal of actions directed by the SNMP Manager

SNMP Trap Types

Trap TypeTrap NameDescription

0

ColdStart

The SNMP agent initialized its configuration tables.

1

WarmStart

The SNMP agent re-initialized its configuration tables.

2

LinkDown

The state of a network adapter on the SNMP agent changed from up to down.

3

Linkup

The state of a network adapter on the SNMP agent changed from down to up.

4

authenticationFailure

The SNMP agent received a message from an SNMP manager, but the message contained an invalid community name.

5

egpNeighborLoss

The SNMP agent could not communicate with its Exterior Gateway Protocol (EGP) peer.

6

enterpriseSpecific

Reserved for vendor-defined error conditions and error codes.

Communication

  • UDP is the only protocol being used.
  • By default SNMP uses port 161 for request / response.
  • Commands for Trap and Inform use port 162 for communication.

Implementation Architecture

  • JobScheduler Monitoring Interface 
    • is moved from operation as a job to operation in a servlet container
    • works independently from JobScheduler
    • uses the JobScheduler database as exclusive source of information
  • JobScheduler SNMP Agent
    • is implemented as a concurrent process in the JobScheduler Monitoring Interface

 

 

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