Network Monitoring and Maintenance Chapter Summary

The following section is a summary of the major points you should be aware of in this chapter.

Network Maintenance Fundamentals Overview

1. Network maintenance is an integral component of a network management methodology
2. Network maintenance activities are either structured or interrupt-driven (ad-hoc)
3. A structured or scheduled network maintenance approach is based on predefined plan
4. Ad-hoc maintenance activities are those that are performed when any issues arise
5. A structured maintenance approach leverages proactive monitoring
6. An ad-hoc approach increases the number of resources required to support the network

Network Maintenance Tasks

1. Network maintenance tasks are simply tasks that are performed on a day-to-day basis
2. The following is a list of common network maintenance tasks:

1. Installing, replacing or upgrading both hardware and software
2. Monitoring, tuning and optimizing the network
3. Documenting the network and maintaining network documentation
4. Securing the network from both internal and external threats
5. Planning for network upgrades, expansions, or enhancements
6. Scheduling backups and restoring services or the network from backups
7. Ensuring compliance with legal regulations and corporate policies
8. Troubleshooting problem reports
9. Maintaining and updating device configurations

An Overview of Network Management Models

1. Network management models are general guidelines running and maintaining a network
2. There are several network management models that are available
3. You should select the network management model best aligned with your business goals
4. Commonly referenced network management models include the following:

1. Telecommunications Management Network
2. FCAPS
3. Information Technology Infrastructure Library
4. Cisco Lifecycle Services

1. The TMN is a model defined by ITU-T for managing systems in a communications network
2. The TMN is referenced in ITU-T Recommendation M.3010
3. The TMN was originally developed to provide a framework for service providers
4. The TMA defined four management architectures at different levels of abstraction:

1. A functional architecture
2. An information architecture
3. A physical architecture
4. A logical layered architecture

1. The TMN logical layered architecture includes an additional four layers of abstraction:

1. The Business Management Layer
2. The Service Management Layer
3. The Network Management Layer
4. The Element Management Layer

1. FCAPS is the ISO TMN model and framework for network management
2. The FCAPS fault management life cycle includes the following tasks:

1. Fault and problem detection
2. Handling and acknowledging alarms sent by devices
3. Fault and problem isolation using a filtration and correlation process
4. Fault correction and recovery
5. Tracking problems through resolution via a trouble ticketing system

1. Configuration management encompasses the management of actual device configurations
2. Configuration management encompasses the configuration change control process
3. Configuration management  includes tracking and logging changes to device configurations
4. Accounting management covers methods to track usage statistics and costs
5. Performance management covers the tracking of system and network statistics
6. Performance management includes baselining, and improving performance, e.g. using QoS
7. Performance management can provide valuable data for capacity planning
8. Security management addresses access rights that include authentication and authorization
9. Security management is concerned with securing access to network devices
10. Security management may also include additional tasks such as integrating firewalls
11. ITIL is a set of best practices for ITSM, IT development and IT operations
12. ITIL is organized into a set of texts which are defined by related functions
13. The five processes or sets defined in ITILv3 are:

1. Service Strategy
2. Service Design
3. Service Transition
4. Service Operation
5. Continual Service Improvement

1. The Cisco PPDIOO model encompasses all steps from network vision to optimization
2. PPDIOO stands for prepare, plan, design, implement, operate, and optimize

IOS Maintenance and Monitoring Tools

1. Cisco provides a plethora of tools that can be used for both maintenance and monitoring
2. The EEM is part of the Cisco Embedded Automation Systems (EASy) toolkit
3. The EASy toolkit combines the following embedded management technologies with EEM:

1. Cisco IP Service Level Agreements (IP SLAs)
2. Expression MIB
3. Network-Based Application Recognition (NBAR)
4. Flexible NetFlow
5. Enhanced Object Tracking
6. Cisco IOS Shell (IOS.sh)

1. EEM is a powerful and flexible subsystem that provides real-time network event detection
2. EEM provides onboard automation and increases the intelligence of network devices
3. EEM supports of the use of scripts which can be configured using the CLI or using Tcl
4. IOS IP SLA allows you to monitor, analyze and verify IP service levels for IP applications
5. IOS IP SLA uses active traffic monitoring to measure network performance
6. IOS IP SLA measures and monitors performance metrics like jitter, latency, and packet loss
7. IOS IP SLA is comprised of two components, which are the source (agent) and the target
8. IOS IP SLA operations can be broadly categorized into the following five functional areas:

1. Availability monitoring
2. Network monitoring
3. Application monitoring
4. Voice monitoring
5. Video monitoring

1. Logging messages and events both locally and to a syslog server is a core maintenance task
2. Syslog allows a host to send event notification messages across IP networks
3. Syslog messages are sent to event collectors called syslog servers or syslog daemons
4. A syslog daemon or server is an entity that listens to the syslog messages that are sent to it
5. Syslog uses User Datagram Protocol (UDP) as the underlying transport mechanism
6. The syslog client sends messages to the syslog sever, specifying a destination port of 514
7. Syslog messages cannot exceed 1,024 bytes in size
8. Syslog messages contain three distinct parts, which are the priority, header, and message
9. When configuring logging, synchronize the device clock manually or using NTP
10. The Simple Network Management Protocol, SNMP, is a widely used management protocol
11. SNMP can be used to collect statistics, monitor device performance and for baselining
12. SNMP is an Application Layer (Layer 7) protocol
13. SNMP uses UDP as the Transport layer protocol, using UDP ports 161 and 162
14. An SNMP network consists of a management system, agents, and managed devices
15. The management system executes monitoring applications and controls managed devices
16. An SNMP agent resides on each managed device
17. SNMP agents capture data from Management Information Bases (MIBs)
18. A managed element, such as a router, switch, or firewall, is accessed via the SNMP agent
19. Managed devices are monitored and controlled using read, write and trap commands
20. The read command is used by an NMS to monitor managed devices
21. The write command is used by an NMS to control managed devices
22. SNMP trap command is used by managed devices to report events to the NMS
23. Devices can be configured to send SNMP traps or informs to an NMS
24. SNMP traps are messages that alert the SNMP manager of a condition on the network
25. SNMP informs are SNMP traps that include confirmation of receipt from the manager
26. There are three versions of SNMP, which are versions 1, 2, and 3
27. SNMPv1 is widely used and is the de facto network-management protocol
28. SNMPv2 revises SNMPv1 and includes improvements to the original SNMPv1 standard
29. SNMPv3 provides additional security services not available in previous versions
30. Cisco IOS NetFlow is a powerful maintenance and monitoring tool
31. Cisco IOS NetFlow reports on traffic statistics, e.g. packets and bytes
32. The device on which NetFlow is configured sends out information that it has collected
33. Cisco IOS NetFlow has the ability to differentiate between traffic flows
34. An IP flow is based on a set of 5 and up to 7 IP packet attributes which may include:

1. Destination IP address
2. Source IP address
3. Source port
4. Destination port
5. Layer 3 protocol type
6. Class of Service
7. Router or switch interface

1. Cisco IOS NetFlow stores flow information in the NetFlow cache or simply the flow cache
2. Collected NetFlow data can be access via the CLI or using a NetFlow Collector
3. NBAR is an intelligent classification engine in Cisco IOS software
4. Network Based Application Recognition that can recognize a wide variety of applications
5. The NBAR Protocol Discovery (PD) feature can collect application and protocol statistics
6. NBAR uses PDLMs for protocol and application recognition
7. The use of PDLMs allows NBAR to recognize additional protocols and applications
8. The configuration archive feature allows configs to be saved in the configuration archive
9. The configuration replace and configuration rollback allows for configuration rollbacks
10. The Command Scheduler allows you to run exec commands on a regular basis on a router
11. The IOS Command Scheduler has 2 processes: policy lists and the scheduler
12. Policy lists contain the exec commands that you want to be executed on the router
13. The scheduler is used to configure when these commands will be run

Additional Maintenance and Monitoring Tools

1. In addition to IOS tools, Cisco provides the following maintenance and monitoring tools

1. Cisco Router and Security Device Manager
2. Cisco Configuration Professional
3. Cisco Configuration Assistant
4. Cisco Network Assistant
5. CiscoWorks LAN Management Solution (LMS)

1. SDM is a Web-based (GUI) device-management tool for Cisco access routers
2. SDM can be used for monitoring and troubleshooting tasks
3. CCP is also a GUI based device management tool for Cisco access routers
4. CCP can be used for network monitoring and maintenance tasks
5. CCA is used for the Cisco Smart Business Communications System
6. CCA is a Web-based (GUI) tool
7. CCA includes the System Dashboard, Topology View, or Front Panel View
8. CNA is a GUI-based tool
9. CNA can be used to apply common services across switches, routers, and access points
10. The CiscoWorks LAN Management Solution is comprised of several software applications
11. LMS provides monitoring, and troubleshooting capabilities
12. CiscoWorks LMS can be used for the configuration and administration of campus networks
13. CiscoWorks LMS includes the following software applications:

1. Resource Manager Essentials (RME)
2. CiscoWorks Health and Utilization Monitor
3. Device Fault Manager (DFM)
4. Internetwork Performance Monitor (IPM)