Network ManagementNetwork Management

Chapter 18

ObjectivesObjectives• Describe how configuration management

documentation enables you to manage and upgrade a network efficiently

• Conduct network monitoring to identify performance and connectivity issues

• Explain how to optimize network performance

OverviewOverview

Introduction to Network Introduction to Network ManagementManagement

• Complicated networks are vulnerable• Configuration management is necessary• Configuration management prevents problems

when upgrading

Three Parts to Chapter 18Three Parts to Chapter 18

• Network Configuration Management• Monitoring Performance and

Connectivity• Network Performance Optimization

Network Configuration Management

• Network Configuration Management– Configuration Management

Documentation– Wiring Schematics or Diagrams

• Configuration Management Documentation– Wiring diagrams– Network diagrams– Baselines– Policies, procedures, and configurations– Regulations

• Wiring Schematics or Diagrams– Wiring diagram/wiring schematic

• How the wires connect to various switches, etc.• Wiring standards used (CAT53, 568A, fiber, etc.)• Every cable run, telecom closet, etc.• Cross-connects, demarcs, etc.• Telephone runs

Figure 18.1 Wiring diagram overview

Figure 18.2 Wiring diagram detail

• Physical and Logical Network Diagrams– Information not included in wiring

diagrams

• Physical Network Diagram– Physical runs– Defines types of connections– Routers, switches, servers, CSU/DSU, etc.– Created by network administrator

• Using standardized network topology icons• Using software utility like MS Visio

Figure 18.3 Physical network diagram

Figure 18.4 Sample network topology icons

Figure 18.5 Visio in action

• Logical Network Diagram– Broadcast domains (circles)– Internet connections (clouds)– Static IP addresses of significant systems– Only critical switches or routers

Figure 18.6 Logical network diagram

• Baselines– Benchmark of when everything is working

correctly– Commit to creating often and comparing– Log of performance indicators

• CPU usage• Network utilization• Other performance measurements• Windows Performance Monitor

• Policies– Acceptable use policy

• What people can and cannot do with network hardware and software

– User training– Security policy

• Level of access for employees• Password complexity and much more

• Procedures– What to do

• When upgrading components• When adding new user accounts

• Configurations– How software should be configured– How hardware should be configured– Results of the procedures

Figure 18.7 Section of SHOW CONFIG

• Regulations– Rules governing behavior in the workplace– How to keep network and people safe and

productive– Included in configuration management

documentation

• Change Management Documentation– CompTIA separates detailed overview of

network from how to upgrade it– Normally these are combined into the

change management documentation– Consult documentation before major

changes

Monitoring Performance and

Connectivity

• Monitoring Tasks– Create baselines– Ongoing monitoring– Various logs

• Monitoring Tools– Windows Performance Monitor (PerfMon)

• Monitors behavior of hardware and software• Monitors locally or remotely

• Configuring Performance Monitor– Object

• System Components• CPU, memory, disk drives, etc.

– Counter• A measurable feature of an object

– Views• A variety of ways of presenting information• Real-time or logged

• Configuring Performance Monitor– Add counters and objects– For logging, must add entire object– Monitor local or remote computer– Save log files for a snapshot of a point

in time

Figure 18.8 Performance Monitor in action

Figure 18.9 Monitoring a remote computer

Figure 18.10 Selecting performance objects

Figure 18.11 Logging data

Figure 18.12 Selecting a log file

Figure 18.13 Replaying a log file

• Create multiple baselines– System at rest– System in use

• Revisit and monitor changes to baseline

• Third-party network monitoring tools– Often expensive– Generate baselines– Monitor in real-time– Alert administrator to problems– Can act as intrusion detection

systems (IDS)– Example: IPSentry by RGE, Inc.

Figure 18.14 IPSentry at work

• More about logs– Every OS generates logs– Three types (Windows examples)

• Application logs• Security logs• System logs

• Log Viewers– Windows Event Viewer– Linux stores logs in /VAR/LOG

• Use text editor to view– Mac OSX GUI viewer called Console

Figure 18.15 Event Viewer in Windows Vista

Network Performance Optimization

• Overview– Network admin keeps network running– Users notice problems quickly– CompTIA Network+ requirements

• Caching• Controlling data throughput• Keeping resources available

• Caching– Storing requested data in hopes it will be

needed again [in the short term]– Works in many ways on a network– Reduces network workload

Figure 18.16 Pausing a video on YouTube

Figure 18.17 Hulu.com (I love this site!)

• Controlling Data Throughput– Most networks have limited bandwidth

• Growing use• It will eventually get slower• Latency-sensitive applications need consistent

bandwidth• Apps like streaming video require high bandwidth

• Methods for Controlling Data Throughput– Throttling bandwidth

• Quality of Service (QoS)–Priority to certain ports–Layer 2 of the OSI model

• Traffic Shaping (a.k.a. bandwidth shaping)–Priority by TCP/UDP port number–Layers 3 and 7 of the OSI model

Figure 18.18 Traffic shaping on a SOHO router

• Keeping Resources Available– High availability– Fault tolerance– Data backup

• Data Backup– Desktop or individual server– Enterprise backup– Backup media

• Tape• Local hard drive• Networked storage

Figure 18.19 Windows Backup

• Archive bit– A.k.a. archive attribute– Key to effective backups– Turned “on” when a file is saved– Some applications turn it on when

they open a file

Figure 18.20 The archive bit on these files is on.

• Backup programs and the archive bit– Depending on backup function selected

• Only backs up files with the archive bit on• Backs up selected files, ignoring state of archive• Turns off archive bit for every file backed up

– Archive bit off means file was backed up– Archive bit on means file has been changed

• Types of backup– Normal backup – all selected files backed up

and archive bit turned off– Copy backup – like normal without touching

the archive bit– Incremental backup – all selected files with

archive bit turned on; turns off bit– Differential backup – all selected files with

archive bit turned on; leaves bit as is– Daily backup – all files changed; leaves bit off

Figure 18.21 Incremental vs. differential

Figure 18.22 Restoring from backups

• Backup strategies– Must meet organization’s need– Must be able to easily restore– Have a regimen

• What to do with backup media• Rotate media

–Grandfather, father, son (GFS)

• Other factors in a backup strategy– Uninterruptible power supply (UPS) pro-

tects against short-term power outages– Backup Generator protects against long-

term power outages– RAID and Redundant Hardware

• System automatically uses redundant component after a failure

• Works normally and buys time for administrator to replace failed component

• Redundant Array of Independent Disks (RAID)– RAID 0

• Data striping across multiple disks (2 minimum)– RAID 1

• Data mirroring (2 disks)– RAID 5

• Disk striping with distributed parity (3 minimum)

• Other Redundant Hardware– Redundant power supplies– Redundant network connections– Cluster Servers and Load Balancing

• Cluster servers– Multiple identical servers– If a server goes down, others pick up the

load– Need cluster-aware operating system, such

as Windows Server for the Enterprise