cs 453 computer networks
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CS 453 Computer Networks. Lecture 22 Network Management. Network Management. We have discussed a lot of network examples that have a very small number of hosts, routers, switches and links - PowerPoint PPT PresentationTRANSCRIPT
CS 453CS 453Computer NetworksComputer Networks
Lecture 22Lecture 22
Network ManagementNetwork Management
Network Management
We have discussed a lot of network examples that have a very small number of hosts, routers, switches and links…but in the real world networks can have thousands of devices and links, and span cities, countries, continents, and the globeIn many important ways, networks are the life blood of many organizations and critically important to individuals
Network Management
A network that does not run reliably, stably and efficiently can have devastating consequences…
Imagine a network failure for an airlines operations system…
…or the Air Traffic control system…
…or the electric power grid
Network Management
This becomes more and more important with network delivered services like VoIP Streaming video On-demand Hi-Res video/audio Collaboration and video conferencing
Network Management
Bottom line- We need to monitor, manage, Troubleshoot Repair
Networks and do this very well
Network Management
Some network management activities Detecting an interface or component failure Monitor hosts on the network Traffic monitoring and resource deployment Recognizing frequent changes in router tables Setting standards for SLAs Intrusion detection and other security threats
Network Management
International Standards Organization’s Five Areas of Network Management Performance Management
Quantify, measure, track, analyze and control network performance
Fault managementIdentify, log and respond to faults in a network
Like performance management, but short-term specific problem focused
Network Management
International Standards Organization’s Five Areas of Network Management
Configuration managementHow are network devices configured
…and keeping track of these configurations Accounting
Tracking resource utilization
Quota management, usage charges, resource access Security management
Monitoring and managing network (and related) access in accordance with defined policies
Network Management
Network Management Architecture –very high level
Managing entityNetwork administrator/network management workstationNOC (most likely)
Managed devicesRouters, switches, hosts, hubs, printers, etc.
MIB – Management Information Base (more on this…)
Network management protocolA well defined protocol for communications and control between managing entities and managed devices
Network ManagementNetwork Management Architecture –very high level
From: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
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Network management protocol There are several, notably… OSI –Common Management Information
Services Element/Common Management Information Protocol (CMISE/CMIP)
Simple Network Management Protocol – SNMP
For IP networks
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MIB – Management Information Base Collections of discrete and organized pieces
of information about managed devices Sort of a virtual database …to be collected from managed devices by
managing entities… …usually as needed
Network Management
MIB – made up of MIB objects MIB objects are the information elements
maintained by managed devices MIB tables – MIB objects with recurrent or
multiple instances of data elements MIB modules – groupings of related MIB
objects
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Each type of managed object has its own set of MIB objects
MIB objects are defined by a data definition language – Structure of Management Information – SMI Subset of ANS.1 - abstract syntax notation 1
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Object descriptors
1.3.6.1.4.1.9.3.3.1
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SMI has several constructs OBJECT-TYPE
Defines objects MODULE-IDENTITY
Defines modules of objects NOTIFICATION-TYPE
Defines the kinds of messages that agents generate MODULE-COMPLIANCE
Defines the set of objects that must be defined within a module
AGENT-CAPABILITIESDefines agents cabilities regarding object and event notifications
Network Management
SMI basic data types INTEGER – 32 bit integers or list of named constants INTEGER32 – 32 bit integers Unsigned32 – 32 bit unsigned integer OCTET STRING – byte string up to 65K bytes long OBJECT IDENTIFER – defined structure name IPaddress – 32 bit IP address in network byte order Counter32 – 32 bit modulo 232 counter Counter64 – 64 bit modulo 264 counter Gauge32 – counter with 0-232 limit TimeTicks – Time in 1/100 seconds Opaque – uninterrupted string
Network ManagementSMI object definition
ipInDelievers OBJECT-TYPESYNTAX Counter32MAX-ACCESS read-onlySTATUS currentDescriptions
“IP datagrams delivered”::={ ip 9 }
Network ManagementIETF – has developed many MIB object definitions
Network vendors develop their own MIB object definitions
There are 100s of MIB objects
Network ManagementSNMPv1
Simple objects, simple protocol, MIB tables
SNMPv2 Modules
SNMPv3 Message integrity Source authenication encryption
Network Management
SMI basic data types INTEGER – 32 bit integers or list of named constants INTEGER32 – 32 bit integers Unsigned32 – 32 bit unsigned integer OCTET STRING – byte string up to 65K bytes long OBJECT IDENTIFER – defined structure name IPaddress – 32 bit IP address in network byte order Counter32 – 32 bit modulo 232 counter Counter64 – 64 bit modulo 264 counter Gauge32 – counter with 0-232 limit TimeTicks – Time in 1/100 seconds Opaque – uninterrupted string
Network Management
Example – managed objects in MIB-2 system groupName Data type Description (RFC 1213)
sysDescr OCTET STRING Name & version of system hw, OS, Network software
sysObjectID OBJECT IDENTIFER
ID – kind of box it is
sysUpTime TimeTicks Time since last reboot
sysContact OCTET STRING Who manages this thing
sysName OCTET STRING Assigned name for this device
sysLocation OCTET STRING Physical location for this device
sysServices Integer32 Code for services available
Network Management
Example – managed objects in MIB-2 udp moduleName Data type Description (RFC 1213)
udpInDatagrams Counter32 UDP datagrams delivered
udpNoPorts Counter32 Number of received datagram where there was no app assigned to port
udpInErrors Counter32 No. of received datagrams that could not be delivered
udpOutDatagrams No. of datagrams sent from this device
udpTable Sequence of udpEntry
Sequence of udpEntry objects – port open by an application
Network Management
Two more PDUs in SNMPv2 GET BULK REQUEST – iterative GET
REQUEST (from manager to agent) INFORM – an acknowledged trap
NOTIFY – event notification – same as trap, added in SNMPv2
Network ManagementSNMPv2 PDU
From: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
PDU type—Identifies the type of PDU transmitted (Get, GetNext, Inform, Response, Set, or Trap). • Request ID—Associates SNMP requests with responses. • Error status—Indicates one of a number of errors and error types. Only the response operation sets this field. Other operations set this field to zero. • Error index—Associates an error with a particular object instance. Only the response operation sets this field. Other operations set this field to zero. • Variable bindings—Serves as the data field of the SNMPv2 PDU. Each variable binding associates a particular object instance with its current value (with the exception of Get and GetNext requests, for which the value is ignored).
Network ManagementSNMPv1 Trap PDU
From: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm
Enterprise—Identifies the type of managed object generating the trap. • Agent address—Provides the address of the managed object generating the trap. • Generic trap type—Indicates one of a number of generic trap types. • Specific trap code—Indicates one of a number of specific trap codes. • Time stamp—Provides the amount of time that has elapsed between the last network reinitialization and generation of the trap. • Variable bindings—The data field of the SNMPv1 Trap PDU. Each variable binding associates a particular object instance with its current value.
Network Management
Network Management
Network Management
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More things to see http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/
snmp.htm http://en.wikipedia.org/wiki/Network_performance_management http://en.wikipedia.org/wiki/Snmp http://www.cotse.com/tools/netman.htm
TCP/IP http://www.redbooks.ibm.com/Redbooks.nsf/RedbookAbstracts/gg243376.html?Open