Network Administration CNET443 1 Chapter 5 SNMP Management

Network Administration CNET-443 1 Chapter 5 SNMP Management

Outline 2 SNMPV 3 key features SNMPV 3 documentation architecture SNMPV 3 architecture Elements of an entity Names Abstract service interfaces SNMPV 3 applications Command generator Command responder Notification originator Notification receiver Proxy forwarder SNMPV 3 management information base Security threats Security model Message format

SNMP V 3 Features 3 Modularization of Architecture and Documentation Continued usage of legacy SNMP entities Application services and primitives Formulizes messages in use in earlier versions Improved Security Continued and formulized Access Policy

SNMPV 3 Documentation Architecture 4 SNMP document architecture addresses how existing documents and new documents could be designed to be autonomous and at the same time be integrated to describe different SNMP frameworks. Represented as follows:

SNMPV 3 Architecture 5 SNMP network management consists of several nodes, each with an SNMP entity. Interact with each other to monitor and manage the network and resources. Architecture of an SNMP entity is defined as the elements of an entity the names associated with them. Three kinds of naming: Ø Naming of entities Ø Naming of identities Ø Naming of management information

SNMPV 3 Architecture: Elements of an Entity 6

Names 7 Naming of entities, identities and management information is part of SNMPv 3 specifications Two names are associated with identities: Principal and security. Name Principal is the who requesting services. It could be a person or an application. The security. Name is a human readable string representing a principal. The principal could be a single user. The principal can be given a security name administratively.

Abstract Services Interfaces 8 Subsystems in an SNMP entity communicate across an interface. Abstract services interface is generic and independent of specific implementation. See Figure:

SNMPV 3 Applications 9 SNMPv 3 formally defines five types of applications. Not same as the functional model that the OSI model addresses. May be considered as application service elements. They are: Ø Command Generator Ø Command Responder Ø Notification Originator Ø Notification Receiver Ø Proxy Forwarder

Command Generator 10 Used to generate get- request, get-nextrequest, get-bulk and set-request messages. Processes the response received for the command sent. Command generator application is associated with the network manager process. Command Generator Application:

Command Responder 11 Processes the get and set requests destined for it. Received the legitimate nonauthoritative remote entity. Performs the appropriate action of get or set on the network element. Prepares a get response message. Sends it to the remote entity that made the request. As shown in Figure:

Notification Originator 12 Generates either a trap or an inform message. Function is somewhat similar to command responder. Except it needs to find out where to send the message Also what SNMP version and security parameters to use. The target that the notification should be sent is obtained from the target group.

Notification Receiver 13 Receives SNMP notification messages. Registers with the SNMP engine to receive these messages. Same as the command responder does to receive get and set messages.

Proxy Forwarder 14 Performs a function similar to proxy server. The term proxy is used to refer to a proxy forwarder application that forwards SNMP requests, notifications and responses. Proxy forwarder handles four types of messages: Ø Messages generated by command generator Ø Command responder Ø Notification Generator Ø Report indicator

SNMPV 3 MIB 15

SNMPV 3 MIB 16

Security 17 One of the main objectives in developing SNMPv 3. Following aspects have been discussed in SNMPv 3 specifications: v Authentication v Privacy of information v Authorization v Access Controls

Security Threats 18 Four types of threats: Modification of information 2. Masquerade 3. Message stream modification 4. Disclosure As shown in following figure: 1.

Security Model 19

Message Format 20

21 Thanks