1 Introduction to Internet Network Management Mi-Jung Choi Dept. of Computer Science KNU

2 Table of Contents Background –Origins of Internet –Origins of Internet Network Management –Evolution of SNMP –SNMP Standards and RFCs SNMP Basic Concepts –Network Management Architecture –SNMP Protocol Architecture –Proxies

3 Internet Network Management Also referred to as SNMP-based Network Management Simple Network Management Protocol (SNMP) is often referred to as the Internet Network Management Framework which includes –management architecture –structure of management information –management protocol –plus related concepts... Most widely used in computer communication networks Internet Engineering Task Force (IETF) is responsible for SNMP standardization

4 Origins of Internet ARPANET (formed by US DoD, 1969) connecting four geographically separated computers in US 23 computers in ARPANET (1971) Computers in UK and Norway were connected (1973) TCP/IP protocol suite as ARPANET’s standard protocol (late 70’s) TCP/IP as NFSNET’s standard protocol (1984) Continued growth throughout the 80’s and 90’s Need for the management of rapidly growing Internet!

5 Origins of Internet NM Internet Control Message Protocol (ICMP) –until late 70’s, e.g., Ping utility Simple Gateway Monitoring Protocol (SGMP) High-level Entity Management System (HEMS) –generalized version of Host Monitoring Protocol (HMP) SNMP –enhanced version of SGMP –an interim solution CMIP over TCP/IP (CMOT) –long-term solution –did not go very far

6 Evolution of SNMP SNMPv1 –draft came out in 1988 and became full Internet standard in 1990 –most workstations, bridges, routers, switches and hubs are now equipped with SNMP agent –many resource MIBs (including systems & applications) have been defined RMON (1995) –Remote Monitoring, extends the SNMPv1 MIB and functions SNMPv2 –attempted to improve the deficiencies of SNMPv1 –Full Internet Standard SNMPv3 –internet drafts came out in Feb. 1998, adding security features –now a full Internet Standard

7 IETF Standardization Process (RFC2026) IETF forms a working group (WG) for a specific task –WG generates one or more internet drafts (ID) –ID document can follow one of three tracks (1) standards track, (2) informational, (3) experimental Internet documents are published as RFCs Internet Proposed Standard Internet Draft Standard Internet Full Standard Other status: –Obsolete: a document that is replaced by an updated version –Historic: a document that is retired The latest status on IETF NM RFCs can be found from

8 SNMP Protocol RFCs DescriptionPublishedRFCStatus SNMPv1 ProtocolAug Obsoleted by 1098 SNMPv1 Protocol (republished)Apr Obsoleted by 1157 SNMPv1 Protocol (republished)May Historic Secure SNMP ProtocolJuly Historic SNMPv2 Protocol OperationsMay Obsoleted by 1905 SNMPv2 Transport MappingsMay Obsoleted by 1906 SNMPv2 Protocol Operations (updated) Jan Draft Standard SNMPv2 Transport Mappings (updated) Jan Draft Standard

9 SNMPv1 Standards DescriptionPublishedRFCStatus Structure of Identification of Management Information for TCP/IP- based Internets (SMI) May Full Standard Concise MIB DefinitionsMar Full Standard Management Information Base for Network Management of TCP/IP- based Internet: MIB-II Mar Full Standard

10 SNMP Full Standards RFCTitle 3418 Management Information Base (MIB) for the Simple Network Management Protocol (SNMP) 3417 Transport Mappings for the Simple Network Management Protocol (SNMP) 3416 Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP) 3415 View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP) 3414 User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3) 3413 Simple Network Management Protocol (SNMP) Applications 3412 Message Processing and Dispatching for the Simple Network Management Protocol (SNMP) 3411 An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks 2819 Remote Network Monitoring Management Information Base 2580 Conformance Statements for SMIv Textual Conventions for SMIv Structure of Management Information Version 2 (SMIv2) 1643 Definitions of Managed Objects for the Ethernet-like Interface Types 1213 Management Information Base for Network Management of TCP/IP-based internets:MIB-II 1212 Concise MIB definitions 1155 Structure and identification of management information for TCP/IP-based internets 1065 Structure and identification of management information for TCP/IP-based internets

11 SNMP NM Architecture The manager resides in Network Management Station (NMS) while the agent resides in the managed Network Node The manager requests the agent to perform Set and Get operations on the variables in the Management information Base (MIB) By means of traps the agent occasionally notifies the manager about some events related to network operation MIB Specification Manager Agent MIB Agent MIB Networked Node NMS SNMP

12 SNMP Protocol Architecture Internetwork Manager process SNMP UDP IP Network-dependent protocols Agent process SNMP UDP IP Network-dependent protocols User processes FTP, etc TCP Agent processUser processes SNMP UDP FTP, etc TCP IP Network-dependent protocols Agent process SNMP UDP IP Network-dependent protocols Central MIB Network Admin HostRouter NMSHost

13 The Role of SNMP Management application SNMP manager UDP IP Network-dependent protocols GetRequest GetNextRequest SetRequest GetResponse Trap Management resources SNMP agent UDP IP Network-dependent protocols GetRequest GetNextRequest SetRequest GetResponse Trap SNMP managed objects network or internet SNMP NMSSNMP agent Application manages objects SNMP messages

14 SNMP Proxy Agent Manager process SNMP UDP IP Network-dependent protocols Network-dependent protocols Network-dependent protocols Network-dependent protocols Mapping function Agent process SNMP UDP IP Protocol architecture used by proxied device Management process Protocol architecture used by proxied device Management station Proxy agent Proxied device

15 Reading and Browsing Read Chapter 4 of the Textbook Visit and browse –IETF Web site: –U. of Twente NM Web site: wwwsnmp.cs.utwente.nl/ietf/rfcs/rfcbystatus.html

16 What will be covered next... Abstract Syntax Notation 1 (ASN.1) Basic Encoding Rules (BER) Structure of Management Information MIB Definitions Standard SNMP MIBs SNMP Operations Developing MIBs etc.