Simple Network Management Protocol ? Background Protocol Background •In April 1989, SNMP was born. •It s an Application Layer Protocol •It’s an Application Layer Protocol •Facilitates the Exchange of Management Information between network devices and is Part of TCP/IP suit b kd i di f C / i •SNMP enables network administrators to 😕 – Manage network performance. – Find and solve network problems Find and solve network problems. – Plan for network growth. •Mainly SNMP is a request? and? response protocol. The Simple Network Management Th Si l N t kM t Protocol (SNMP) Protocol (SNMP) •An Internet? tandard protocol for managing devices on IP networks. •Many kinds of devices support SNMP, eg routers, switches, servers, workstations, printers, modem racks, UPS etc •SNMP helps to monitor simple and standardized items, eg g •Amount of traffic flowing into or out of an interface • Air temperature inside a router. Etc •Devices on the network, contain information about themselves. themselves •Devices keep information about the Status & Devices keep information about the Status & Health on neighbourhood devices & It Self •This information is the heart of Simple Network Management Protocol –SNMP
Network Management and Monitoring Network Management and Monitoring • What operations do you carry out using SNMP h i d i e. g – Shutdown an interface on a router or switch – monitor temperature on a switch and give a p g warning when it is too high or too low • Remote Network Monitoring (RMON) was g( ) developed to help us understand how the network itself is functioning,eg network itself is functioning,eg – It can be used to monitor not only LAN traffic, but WAN interfaces as well WAN interfaces as well Before and After SNMP SNMP’s predecessor is the Simple Gateway Management Protocol (SGMP), Management Protocol (SGMP) • SGMP was Limited to managing Internet routers • SNMP can be used to manage – Unix systems, Unix systems, – Windows – systems, t – printers, – modem racks, power – supplies, and more and even software supplies, and more and even software Human Considerations Human Considerations • Network management requires human resource but at the same time, network management is intended to reduce the workload of your system administration staff. orkload of your system? administration staff • There is no way to predetermine how many people you will need to maintain a l ll management system. The size of the staff varies depending on the size and complexity of the network you re managing. of the network you’re managing. SNMP Versions SNMP Versions • Three versions of SNMP exist. • Version 1 and 2 have a number of Version 1 and 2 have a number of common features. • Version 2 has additional protocol i 2h ddi i l l operations. • Version 3 has Enhanced security support where a community name must b h it t be supplied for authentication SNMP Version 1 (SNMPv1) • It’s defined in RFC 1157 and is a full IETF standard. d d • Security is based on communities, which are Secu ty s based o co u t es, c ae nothing more than passwords: plain? text strings that allow any SNMP? based application strings that allow any SNMP based application that knows the strings to gain access to a device’s management information. d i ‘ ti f ti • There are typically three communities in yp y
SNMPv1: read? only, read? write, and trap. SNMP Version 1 (SNMPv1) SNMP Version 1 (SNMPv1) • Most common Management protocol used in data networks. • Based on Manager? Agent model • U Uses MIB to exchange information MIB h i f i • All commands use UDP / IP protocol – / p connectionless • O Operates at Layer 7 –Application layer t tL 7 A li ti l SNMP Version 2 (SNMPv2) SNMP Version 2 (SNMPv2) • Referred to as community string? based SNMPv2. • It’s defined in RFC 1905, RFC 1906,and RFC 1907, and is an experimental IETF.
Even though it’s p g experimental, some vendors have started supporting it in practice. pp g p • Includes Basic functions of SNMP version 1 • Adds new message types Enhances security by Adds new message types, Enhances security by using community name • It co exists with SNMP version 1 It co? exists with SNMP version 1 • Retrieves large amount of data using limited resources (GetBulk) (G tB lk) SNMP Version 3 (SNMPv3) SNMP Version 3 (SNMPv3) • Defined in RFC 1905, RFC 1906, RFC 1907, RFC 2571, RFC 2572, RFC 2573, RFC 2574, and RFC 2575. 575. • It adds support for strong authentication and private communication between managed i i i b d entities. • Privacy (Encryption) • Authorization and access control • Remote configuration and administration capabilities • Includes Basic functions of SNMP v1 and v2 Includes Basic functions of SNMP v1 and v2 Key elements of SNMP : Key elements of SNMP : • What piece of information is useful for us ? p – Information that can be accessed from a y p p device mainly depend on device capabilities and the MIB • How to access it and change it? – commands can be used to access/change g g , , settings on a device via SNMP eg Set , Get , Get Next , Get Bulk • Where does this information resides ? – In Management Information Base (MIB) Advantages of SNMP Ad t f SNMP • • • • • • SNMP? Standardized protocol: – SNMP is the standard network management protocol for TCP/IP SNMP is the standard network management protocol for TCP/IP networks. Universal acceptance: – All major vendors support SNMP All major vendors support SNMP. Portability: – SNMP is independent of operating system and programming language. anguage. Lightweight: – SNMP will not impact the operation of the device or its performance 100% Extendibility: – SNMP is a core set of operations that remain the same on all managed devices. managed devices. Widely deployed: – SNMP is one of the popular protocols in the protocol suite, vendor’s are aware of. are aware of. The Structure of Management Information (SMI) (SMI) • SMI provides a way to define managed objects and their behavior • An agent has in its possession a list of the objects that it tracks.
One such object is the objects that it tracks One such object is the operational status of the managed device (for example, up, down, or testing). l ) • NMS can use this information to determine NMS can use this information to determine the overall health of the device on which the agent resides. agent resides The Management Information Base (MIB) • Ad b A database of managed objects that the agent tracks f d bj h h k • Any sort of status or statistical information that can be accessed by the NMS is defined in a MIB. b th NMS i d fi d i MIB • Collection of objects or definitions that define the properties of the managed objects properties of the managed objects • Collection of information that is organized hierarchically • Th They are comprised of managed objects and are i d f d bj t d identified by object identifiers (OID’s) • OID’s are series of numbers that uniquely identify an are series of numbers that uniquely identify an object to an SNMP agent. • Only an abstraction of data and not a physical database Only an abstraction of data and not a physical database
Typical SNMP Network Management Architecture Consists of ? • Network Management Station Network Management Station – Runs NM Application (GUI) – Gathers Information on managed devices present status – Log – Control managed devices Control managed devices • Managed Device – Any type of Node with an Agent • Management Agents Management Agents – Piece of Software or Service • Management Protocol Management Protocol – Used to exchange management Information? SNMP • Management Information Base (MIB) g ( )