Chapter 1: Planning Maintenance for Complex Networks

© 2007 – 2010, Cisco Systems, Inc. All rights reserved. Cisco Public

TSHOOT v6 Chapter 11

Chapter 1:Planning Maintenance for

Complex Networks

CCNP TSHOOT: Maintaining and Troubleshooting IP Networks

Chapter 12© 2007 – 2010, Cisco Systems, Inc. All rights reserved. Cisco Public

Chapter 1 Objectives

This chapter covers the following topics:

• Applying maintenance methodologies

• Maintenance processes and procedures

• Network maintenance tools, applications, and resources


1- Maintenance Models and Methodologies

The objective of network maintenance is to keep the

network available with minimum service disruption and at

acceptable performance levels.

A network engineer’s job description can include

tasks related to:

Device installation and maintenance, Failure response, Network

performance, Business procedures: Includes tasks such as

documenting, compliance auditing, and service level agreement

(SLA) management and Security.


1- Maintenance Models and Methodologies

Method of performing network maintenance:

1. Interrupt driven maintenance : is the most basic method of

performing network maintenance. For example is that a

company’s network engineer reviews and improves the

security of the network only when security concerns or

incidents are reported.

2. structured network maintenance : Structured network

maintenance predefines and plans much of the processes

and procedures. This proactive approach not only reduces

the frequency and quantity of user, application, and

business problems, it also renders the responses to

incidents more efficiently.


Benefits of Structured Maintenance over Interrupt-driven Maintenance

1. It is Proactive.

2. Reduced network downtime: Discover and prevent

problems before they happen.

3. More cost effective: Performance monitoring and capacity

planning for budgeting and future networking needs.

4. Better alignment with business objectives

5. Improved network security : Attention to network security

is part of structured network maintenance


Maintenance Models and Organizations

1. IT Infrastructure Library (ITIL): This is a framework of

best practices for IT Service Management.

2. ISO – FCAPS categories (FCAPS is first letter of each):

• Fault management, Configuration management

• Accounting management ,Performance Management

• Security Management

3.ITU-T - Telecommunications Management

Network (TMN

4.Cisco Lifecycle Services Phases - PPDIOO: A

model that helps businesses successfully deploy,

operate, and optimize Cisco technologies in their

network.


The Configuration Management element of the FCAPS model


Network Maintenance Processes and Procedures

A network maintenance plan includes procedures for the following tasks:

1. Accommodating Adds, Moves, and Changes: Affects users,

computers, printers, servers and phones and potential changes in

configuration and cabling.

2. Installation and configuration of new devices: Includes adding

ports, link capacity and network devices. Can be handled by a

different group within an organization, by an external party, or by

internal staff.

3. Replacement of failed devices: Done through service contracts or

by in-house support engineers.

4. Backup of device configurations and software: Good backups of

both software and configurations can simplify and reduce the time the

recovery process takes for failed devices.


Network Maintenance Processes and Procedures

5. Troubleshooting link and device failures: Diagnosing and resolving failures related to network components, links, or service provider connections are essential tasks within a network engineer’s job.

6. Software upgrading or patching: Requires that you stay informed of available software upgrades or patches and use them if necessary. These can address critical performance or security vulnerabilities.

7. Network monitoring: Monitoring operation of the devices and user activity can be performed using simple mechanisms such as router and firewall logs or by using sophisticated network monitoring applications.

8. Performance measurement and capacity planning: This can help determine when to upgrade links or equipment and justify the cost. Facilitates planning for upgrades (capacity planning) to help prevent bottlenecks, congestion and failures.

9. Writing and updating documentation: Current network documentation is used for reference during implementation, administration, and troubleshooting is a mandatory network maintenance task.


Network Maintenance Tools, Applications, and Resources

Console

SSH

Telnet

HTTP

HTTPS

Telnet

SSH

NTP

Syslog

TFTP

FTP

SCP

HTTP(S)

Time Logging

BackupsCLI mgmt

GUI mgmt


NTP Example

service timestamps debug datetime msec localtime show-timezone

service timestamps log datetime localtime show-timezone

!

clock timezone PST -8

clock summer-time PDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00

!

ntp server 10.1.220.3 (to set the ntp server on the router)

(Selected output from the running config)


Logging Services

Events on networking devices can be logged.

• Various events

• Various levels of severity

Events are logged to:

• Console (default)

• Console display

• Buffer

• Server

Examples

• Interfaces up or down

• Configuration changes

• Routing protocol adjacencies

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Logging Services

Logging severity levels on Cisco Systems devices are as follows:

• (0) Emergencies

• (1) Alerts

• (2) Critical

• (3) Errors

• (4) Warnings

• (5) Notifications

• (6) Informational

• (7) Debugging

By default, all messages from level 0 to 7 are logged to the console13


Logging Services

Buffer

• logging buffered [buffer-

size|level]

• May or may not be the default

• By default, messages of all severity levels

are logged to buffer.

• show logging Displays the content of the

buffer

• The buffer is circular, meaning that when

the buffer has reached its maximum

capacity, the oldest messages will be

discarded to allow the logging of new

messages.

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Logging Services

Console

• You can also adjust the logging severity level of the console.

• By default, all messages from level 0 to 7 are logged to the console;

• You can configure the severity level as an optional parameter:

logging console level

• Limits the logging of messages displayed on the console terminal to

the specified level and (numerically) lower levels.

• You can enter the level number or level name.

Note: Level option is not available in old router IOS

versions 15


Logging Services

Server

• logging ip-address command

• Some IOS version it is logging host

• By default, only messages of severity level 6 or lower will be logged to the

syslog server.

• This can be changed by entering the logging trap level command.

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Implementing Backup and Restore Services using FTP

Copy using FTP with specified username and password

R1(config)# ip ftp username cisco

R1(config)# ip ftp password cisco

R1(config)# exit

R1# copy running-config ftp:

Address or name of remote host [10.1.152.1]?

Destination filename [R1-test.cfg]?

Writing R1-test.cfg !

2323 bytes copied in 0.304 secs (7641 bytes/sec)

Chapter 1: Planning Maintenance for Complex Networks

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