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Introduction to Internet Network Management
Mi-Jung Choi
Dept. of Computer Science
KNU
Email: [email protected]
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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
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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
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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!
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Origins of Internet NM
• Internet Control Message Protocol (ICMP) – until late 70’s, e.g., Ping utility
• Simple Gateway Monitoring Protocol (SGMP) - 1987• 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
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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
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IETF Standardization Process (RFC2026)
http://www.ietf.org/rfc/rfc2026.txt• 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 http://wwwsnmp.cs.utwente.nl/ietf/rfcs/rfcbystatus.html
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SNMP Protocol RFCs
Description Published RFC Status
SNMPv1 Protocol Aug. 1988 1067 Obsoleted by 1098
SNMPv1 Protocol (republished) Apr. 1989 1098 Obsoleted by 1157
SNMPv1 Protocol (republished) May 1990 1157 Historic
Secure SNMP Protocol July 1992 1352 Historic
SNMPv2 Protocol Operations May 1993 1448 Obsoleted by 1905
SNMPv2 Transport Mappings May 1993 1449 Obsoleted by 1906
SNMPv2 Protocol Operations(updated)
Jan. 1996 1905 Draft Standard
SNMPv2 Transport Mappings(updated)
Jan. 1996 1906 Draft Standard
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SNMPv1 StandardsDescription Published RFC Status
Structure of Identificationof Management
Information for TCP/IP-based Internets (SMI)
May 1990 1155 Full Standard
Concise MIB Definitions Mar. 1991 1212 Full Standard
Management InformationBase for Network
Management of TCP/IP-based Internet: MIB-II
Mar. 1991 1213 Full Standard
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SNMP Full StandardsRFC Title
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 SMIv2
2579 Textual Conventions for SMIv2
2578 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
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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
MIBSpecification
Manager
Agent
MIBAgent
MIB
Networked Node
Networked Node
NMS
SNMPSNMP
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SNMP Protocol Architecture
Internetwork
Manager process
SNMP
UDP
IPNetwork-dependent
protocols
Agent process
SNMP
UDP
IP
Network-dependent protocols
User processes
FTP, etc
TCP
Agent process User processes
SNMP
UDP
FTP, etc
TCP
IP
Network-dependent protocols
Agent process
SNMP
UDP
IP
Network-dependentprotocols
CentralMIB
NetworkAdmin
Host Router
NMS Host
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The Role of SNMP
Management application
SNMP manager
UDP
IP
Network-dependent protocols
Get
Req
ue
st
Get
Nex
tReq
ue
stS
etR
equ
est
Get
Res
po
ns
e Tra p
Management resources
SNMP agent
UDP
IP
Network-dependent protocols
Get
Req
ue
st
Get
Nex
tReq
ue
stS
etR
equ
est
Get
Res
po
ns
e Tra p
SNMP managed objects
network orinternet
SNMP NMS SNMP agent
Application manages objects
SNMP messages
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SNMP Proxy Agent
Manager process
SNMP
UDP
IP
Network-dependentprotocols
Network-dependentprotocols
Network-dependentprotocols
Network-dependentprotocols
Mapping function
Agent process
SNMP
UDP
IP
Protocolarchitecture usedby proxied device
Management process
Protocolarchitecture usedby proxied device
Management station
Proxy agent
Proxied device
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Reading and Browsing
• Read Chapter 4 of the Textbook• Visit and browse
– IETF Web site:
• www.ietf.org
– U. of Twente NM Web site:
• wwwsnmp.cs.utwente.nl/ietf/rfcs/rfcbystatus.html
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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.
