Transcript Advanced Network Management Introduction and Background

Advanced Network Management
Prof. Chadi Assi
[email protected]
EV7.635
1
Text Books and References
 Network Management: Principles and Practice:
Mani Subramanian, Addison Wesley,
ISBN: 0-201-35742-9
 SNMP, SNMPv2, SNMPv3 and RMON1 and 2:
William Stallings, 3rd edition, Addison Wesley,
ISBN: 0-201-48534-6
 Network Management: A Practical Perspective
Leinwand, A. and Fang K., Addison Wesley
 Essential SNMP
Douglas Mauro and Kevin Schmidt, O’Reilly
online version:
http://www.unix.org.ua/orelly/networking_2ndEd/snmp/
 Other RFCs and Research papers
2
Course Outline
 Network Management: Principles, Standards and
Models.
 Computer Networks and the Internet
 Application, Transport and Network layer
 Network Management Protocols and Abstract
Syntax Notation One (ASN.1).
 Simple Network Management Protocol (SNMP)
 Structure of Management Information (SMI),
Management Information Base (MIB).
 SNMPv2
 SNMPv3
 Remote Monitoring (RMON), RMON 1 and 2.
3
Course Outline
 OSI Systems management, Telecommunications
Management Network (TMN), and ATM Network
Management. .
 Network Management Applications (Configuration,
Performance, Fault and Security management).
 Distributed Management Framework (management by
delegation, mobile agent based management, etc.)
 CORBA based management, web based management,
JMX and DMTF.
4
Course Outline
Marking Scheme:
o
o
o
o
Midterm1
Midterm2
Project
Assignments
35%
35%
25%
5%
More info:
www.ciise.concordia.ca/~assi/courses/inse7120.htm
5
Background
 Today’s “Information Infrastructure” (or simply the
Internet) is increasingly growing
o large number of interconnected heterogeneous sub-networks and
a wide range of distributed applications (100s or 1000s of
interacting hardware/software components)
 Other complex systems requiring monitoring,
control



jet airplane
nuclear power plant
Others
 In such a large network, many things can go wrong
o therefore disabling the network or a portion of it and degrading
performance to an unacceptable level!
6
Background
 During the old days, a network can be managed by
using only human efforts!
o In a small system, running few “pings” may help locating the
problem
o As the Internet becomes a large global infrastructure,
automated network management tools are essential
o Standardized tools that can be used across a broad
spectrum of product types are also needed
 Therefore, a network management system (NMS) is
a collection of tools for network monitoring and
control
o Just as an airplane cockpit allows a pilot to monitor, control,
analyze, configure, etc.
7
Network Management
Failure of Interface Card
 A network admin by
monitoring and analyzing
network traffic may detect
problems in any interface
card and replace it
- e.g., increase in checksum
errors in frames sent out by
this interface;
Host Monitoring
 A network admin periodically
checks to see if all hosts are
operational
8
Network Management
Monitoring traffic/resource
deployment
 By monitoring link utilization,
a network admin may
determine system
bottleneck and provision
higher bandwidth link
instead, to avoid congestion
9
Network Management
Rapid changes in routing tables
 If detected may prevent
instabilities in routing and
hence prevent a network
from going down
Intrusion detection
 Network admin requests to
be notified when traffic is
destined to/arrives from a
suspicious source
 Detect the existence of a
certain type of traffic (e.g.,
security attacks)
10
What is Network Management?*
"Network management includes the deployment,
integration and coordination of the hardware,
software, and human elements to monitor,
test, poll, configure, analyze, evaluate, and
control the network and element resources
to meet the real-time, operational
performance, and Quality of Service
requirements at a reasonable cost."
*T.Saydam,
T. Magendaz “From Networks and Network Management into
Service and Service Management” Journal of Networks and System
Management, Vol.4, No.4, Dec. 1996
11
What is Network Management?
 ISO (International Organization for
Standardization) has created a network management
model. 5 areas of network management are classified
-
Performance Management
Fault Management
Configuration Management
Security Management
Accounting Management
 This classification has gained broad acceptance by
vendors of both standardized and proprietary NMS
12
Performance Management
Goal:
Quantify, measure,
report, analyze, and
control the performance
of different network
components (such as
routers, hosts, as well as
end to end abstractions,
such as a path through
the network)
 Two functional categories
- Monitoring (ability to monitor
and track activities on the
network)
- Controlling (ability to make
adjustments to improve network
performance).
 Measuring Performance
- Throughput (whether reduced
to unacceptable level!)
- Response time (i.e. network
delays)
- Utilization
- Error rates (identify
bottlenecks)
- Availability
13
Fault Management
Goal:
Log, detect, and respond
to fault conditions in the
network
Immediate* handling of
transient network
failures (link, host,
router hardware or
software outages)
Faults are to be distinguished
from Errors
- A fault is an abnormal
condition and requires
management attention to
repair (e.g. link cut)
- An Error is a single event!
(e.g. single bit error on a
line)
*performance
management takes longer term view in the face of varying
traffic demands and occasional network device failures.
14
Illustrative scenario
• A client application exchanges data
over a TCP connection with a DB server
• Distinct domains each administered by
a different organization
15
Illustrative scenario
Problem scenario
A clock at an interface in WAN2 that supports T3 link loses
SYNC 4 times a second for 0.25 ms
 intermittent noise causing loss of 0.1% of T3 capacity
 this small noise causes bit errors in a large number of
packets routed over C-D
 Bit errors cause packet losses, either at routers (if IP
header corrupted) or at destinations
16
Illustrative scenario
 performance of TCP connection degrades due to packet loss
 TCP sender interprets this as congestion and hence reduces
its window
 TCP increases its window gradually until new packet loss
 However due to the noise, the TCP window will not increase
 DB transactions by client will last longer
 DB server performance will degrade due to records lock-out,
causing frequent aborts for remote transactions
17
Configuration Management
Goal:
Allow a network manager
to track which devices
are on the network and
the hardware and
software configurations
of these devices.
Consists of the following steps:
- Gather information about
current network, maintain an
up-to-date inventory of all
network components
- Use that data to modify the
configuration of the network
device (reconfiguration*)
Reconfiguration of a network is often desired in response to
performance evaluation or in support of network upgrade, fault
recovery, or security checks.
*
18
Security Management
Goal:
Control access to
network resources
according to well defined
policy.
Identifying sensitive
information (e.g.,
network management
information) and
protecting it
Security at different levels
- Physical & Data Link Levels 
Encryption
-
Network Level  packet
filters
-
Application Level  (host, user
and key) authentication
-
Popular Level  Firewalls &
VPNs
19
Accounting Management
Goal:
Specify, log, and control
user and device access
to network resources
…usage quotas, usage-based
charging, the allocation of
resource-access privileges…
…Accounting reports should
be generated periodically
 A network manager should track
the use of network resources
- A user may be abusing his
access privilege and burdening
the network at the expense of
other users. (e.g., a user may be
violating his service contract)
- Planning for network growth
20
Infrastructure for Network Management
definitions:
managing entity
agent data
managing
data
entity
network
management
protocol
managed devices contain
managed device
managed objects whose
data is gathered into a
agent data
Management Information
Base (MIB)
managed device
agent data
agent data
managed device
managed device
21