SNMP

• What Is Snmp?

  SNMP is the acronym for Simple Network Management Protocol. It is an application layer protocol that involves exchanging of information between Network elements.
  The Simple Network Management Protocol is used to communicate Management Information between the Network Management System and the Network Elements.
  Using SNMP, the Network operators can be able to manage their network elements, identify the fault and can configure the remote system.

  What Are Different Snmp Versions?

  Here are different versions of SNMP - SNMP V1, SNMP V2c, and SNMP V3.
  SNMP version 1 - It is the oldest flavor. It is Easy to set up – only requires a plaintext community.
  SNMP version 2c - It is identical to Version 1, except that it adds support for 64 bit counters.
  SNMP version 3 - It adds security to the 64 bit counters. SNMP version 3 adds both Encryption and Authentication, which can be used together or separately.

    What Is Oid Or Object Identifier?

  An object identifier (or OID) uniquely identifies a managed object in the MIB hierarchy. The MIB hierarchy can be represented as a tree with a nameless root, with various levels , which are assigned by different organizations.
  The managed object getVersion can be uniquely identified either by the object name iso.org.dod.internet.private.enterprise.tdd.snmp.getVersion or by the equivalent object ID, .1.3.6.1.2.1.1.6

• What Is Smi?

  SMI Stands for Structure of Management Information, which defines the rules for describing management information, using Abstract Syntax Notation One (ASN.1).

• What Are The Type Of Managed Objects?

  There are two types of managed objects namely scalar and tabular. 
  Scalar objects define a single object instance.
  Tabular objects define multiple related object instances that are grouped in MIB tables.

• What Is Snmpv2?

  • SNMPv2 is the evolution of SNMPv1 protocol.
  • SNMPv2 support GET-BULK and INFORM operation in addition to the operations supported by SNMPv1.
  • The message format of SNMPv2 GET, GETNEXT, SET are same as SNMPv1 but the message format of SNMPv2 TRAP is different from the SNMPv1 messag format.
  • SNMPv2 also uses the Community based authentication which is same as SNMPv1.

• What Is Inform?

  SNMP INFORM is similar to Traps but is more reliable.
  When an Agent sends a Trap to the Network Management System (Manager), the Manager receives the Trap and no acknowledgement is sent to Agent. By this way, the Agent doesn’t know whether the Trap has been received by Manager or not. 

  Whereas in Inform Request, the Manager upon receiving the Inform Request can acknowledge the Agent with a SNMP Response PDU. By this way, Agent can be able to know whether Inform has reached or not.
  If the Agent didn’t receive the Acknowledgement from the Manager, it can resend the Inform Request again.

• What Is Snmp Trap?

  SNMP TRAP is a type of Asynchronous Notification propagated from the Managed Device to the Network Management System.
  SNMP Traps are generated from the Network Elements when it experiences some error condition.

  • What Is Snmp Set Request?

    SET Request is a Write operation on the Managed Device.
    SET Request is used to set/write values in the Managed Device. Basically it is used by the SNMP Manager applications to configure Network Elements with set of values.

  • What Is Get Bulk Request?

    GET BULK Request is used to retrieve large amount of data from the MIB objects.
    It internally uses series of Get Next operation to retrieve all data from the MIB tables.

    What Are The Basic Commands In Snmp?

    The basic commands in SNMP are,
    1. GET
    2. GET NEXT
    3. GET BULK
    4. SET
    5. TRAP
    6. INFORM

    What Is A Mib?

    MIB is the acronym for Management Information Base.
    MIB comprises of set of managed objects which is organized hierarchically. Each managed object is identified using an Object Identifier, termed as OID.
    The managed object represents the characteristics of the managed device.

    What Is A Managed Device?

    Managed Device is a Network element/device which has the SNMP Agent running in it.
    The Managed device collects/fetches the management information and makes this information available to the Network Management Software.

     Which Ports Are Used In Snmp?

    SNMP uses the UDP port 161 for sending and receiving requests, and port 162 for receiving traps from managed devices.