Network Management - Computer Network Systems - Lecture Slides, Slides of Computer Networks

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Lecture 16

Network Management

slides are modified from Dave Hollinger Docsity.com

Outline

• What is network management?
• Internet-standard management framework
  • Structure of Management Information: SMI
  • Management Information Base: MIB
  • SNMP Protocol Operations and Transport Mappings
  • Security and Administration
• ASN.

CPE 401/601 Lecture 16 : NetworkManagement Docsity.com

Network Management Cases

• Detecting failure of an interface card
• Host monitoring
• Traffic monitoring
• Routing table monitoring (route flapping)
• SLA monitoring
• Intrusion detection
• …

CPE 401/601 Lecture 16 : NetworkManagement (^) Docsity.com 4

ISO network management model

• Performance management
  • quantify, measure, report, analyze, and control performance
• Fault management
  • log, detect, and respond to fault conditions
• Configuration management
  • track devices for hardware and software configurations
• Accounting management
  • specify, log, and control user and device access
• Security management
  • control access to resources according to well-defined policy CPE 401/601 Lecture 16 : NetworkManagement (^) Docsity.com 5

Network Management standards

OSI CMIP

• Common Management Information Protocol
• designed 1980’s:
  • unifying network management standard
• too slowly standardized

CPE 401/601 Lecture 16 : NetworkManagement Docsity.com

Network Management standards

SNMP: Simple Network Management Protocol

• Internet roots
  • SGMP: Simple Gateway Monitoring Protocol
• started simple
  • deployed, adopted rapidly
• growth: size, complexity
• currently: SNMP V
• de facto network management standard

CPE 401/601 Lecture 16 : NetworkManagement Docsity.com

Structure of Management Information

Basic Data Types

• Purpose : syntax, semantics of management data well-defined, unambiguous
• base data types:
  • straightforward
• OBJECT-TYPE
  • data type, status, semantics of managed object
• MODULE-IDENTITY
  • groups related objects into MIB moduleCPE 401/601 Lecture 16 : Network Management Docsity.com

SNMP MIB

CPE 401/601 Lecture 16 : NetworkManagement

OBJECT TYPE: OBJECT TYPE:OBJECT TYPE:

objects specified via SMI OBJECT-TYPE construct

MIB module specified via SMI MODULE-IDENTITY (100 standardized MIBs, more vendor-specific)

MODULE

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SMI: Object, module examples

• OBJECT-TYPE: ipMIB

CPE 401/601 Lecture 16 : NetworkManagement

ipMIB MODULE-IDENTITY LAST-UPDATED “200602020000Z” ORGANZATION “IETF SNPv2 Working Group” CONTACT-INFO “ Keith McCloghrie……” DESCRIPTION “The MIB module for managing IP and ICMP implementations, but excluding their management of IP routes.” REVISION “199411010000Z” ……… ::= {mib-2 48}

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MIB example: UDP module

CPE 401/601 Lecture 16 : NetworkManagement

Object ID Name Type Comments 1.3.6.1.2.1.7.1 UDPInDatagrams Counter32 total # datagrams delivered at this node 1.3.6.1.2.1.7.2 UDPNoPorts Counter32 # underliverable datagrams no app at portl 1.3.6.1.2.1.7.3 UDInErrors Counter32 # undeliverable datagrams all other reasons 1.3.6.1.2.1.7.4 UDPOutDatagrams Counter32 # datagrams sent 1.3.6.1.2.1.7.5 udpTable SEQUENCE one entry for each port in use by app, gives port # and IP address

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OSI

• Object

Identifier

Tree

CPE 401/601 Lecture 16 : NetworkManagement Docsity.com

SNMP protocol

• Two ways to convey MIB info, commands:

CPE 401/601 Lecture 16 : NetworkManagement

agent data Managed device

managing entity

response agent data Managed device

managing entity

trap msg

request

request/response mode trap mode Docsity.com

SNMP protocol: message formats

CPE 401/601 Lecture 16 : NetworkManagement Docsity.com

SNMP security and administration

• encryption : DES-encrypt SNMP message
• authentication : compute, send MAC(m,k):
  • compute hash (MAC) over
    • message (m), secret shared key (k)
• protection against playback: use nonce
• view-based access control
  • SNMP entity maintains database of access rights, policies for various users
  • database itself accessible as managed object! CPE 401/601 Lecture 16 : NetworkManagement Docsity.com