Sunday, December 2, 2007

NETWORK ADMINISTRATION

Executive Summary

As IT capabilities have increased steadily due to improvements in technology and practices, businesses have grown increasingly reliant on the IT infrastructure to support critical business processes and to create new opportunities. Although the most novel and innovative business use of IT technology often occurs at the application level, the importance of core services should not be taken lightly. All the functionality of a reliable, available, and secure IT infrastructure starts with the selection and proper maintenance of the hardware and basic services that form the foundation of that infrastructure.

The Network Administration service management function (SMF) defines and delivers the processes and procedures required to operate basic network services, including Dynamic Host Configuration Protocol (DHCP), Windows Internet Name Service (WINS), and Domain Name System (DNS), on a day-to-day basis. This SMF provides fundamental guidance for operating these services and maintaining the hardware layer on which they reside. It also provides references to appropriate resources for topic-specific operating guidance on hardware and network-level software. The Network Administration SMF resides in the Operating Quadrant of Microsoft® Operations Framework (MOF).



Introduction

The Network Administration SMF presents a unified approach to the operation and maintenance of network infrastructures, including Remote Access Service (RAS), local area networks (LANs), and wide area networks (WANs). This document describes best practices and processes that may be applied generally across a broad range of network configurations and topologies. The Network Administration SMF reflects best practices developed though operation of the extensive and highly complex Microsoft internal networks, with input from partner and customer experience and guidance provided through the IT Infrastructure Library (ITIL), published by the United Kingdom’s Office of Government Commerce (OGC).

This guide provides detailed information about the Network Administration SMF for organizations that have deployed, or are considering deploying, Microsoft technologies in a data center or other type of enterprise computing environment. This is one of the more than 20 SMFs defined and described in Microsoft Operations Framework (MOF). The guide assumes that the reader is familiar with the intent, background, and fundamental concepts of MOF as well as the Microsoft technologies discussed.
An overview of MOF and its companion, Microsoft Solutions Framework (MSF), is available in the MOF Service Management Function Overview guide. This overview also provides abstracts of each of the service management functions defined within MOF. Detailed information about the concepts and principles of each of the frameworks is available in technical papers at http://go.microsoft.com/fwlink/?LinkId=47748.

Audience

This document is written primarily for IT professionals and managers, including network engineers, systems engineers, architects, and others who wish to implement standardized practices and policies within their IT organizations. The guidance provided in this document is intended to facilitate the operation and management of networks in organizations of all sizes, but is aimed primarily at large organizations with complex IT architectures and multiple locations. The guide assumes a professional level of competence and knowledge of fundamental network principles. For those who wish to review network nomenclature, architecture, and other basics, we recommend the Microsoft Press® book, ALS Networking Essentials Plus, Third Edition, ISBN 0-7356-0912-8. To review Microsoft guidance and recommendations for network architecture, please refer to the Microsoft Windows Server System™ Reference Architecture (WSSRA). An overview of WSSRA is available athttp://go.microsoft.com/fwlink/?LinkId=47749.

What’s New

This version of the Network Administration SMF contains updated references to currently available Product Operating Guides (POGs) for Microsoft technologies operated as part of an organization’s network infrastructure. These technologies include DNS, WINS, and DHCP servers installed as part of the Microsoft Windows Server™ 2003 operating system. The guidance in this SMF reflects the current best practices used by the Microsoft IT organization in operating and maintaining the extensive internal Microsoft network.


Network Administration Overview

As defined in MOF, a network consists of the infrastructure components through which computer systems and shared peripherals communicate with each other. It is the most basic level of an IT infrastructure—without network facilities, there is no infrastructure, just a collection of individual computers. The Network Administration SMF is focused on the operation of this basic service.

The Network Administration SMF is situated in the MOF Operating Quadrant, illustrated below in Figure 1. It is closely related to the Storage Management, Directory Services Administration, and Job Scheduling SMFs since it provides a similar foundation on which higher-order IT layers are built.



















Figure 2 illustrates the internal organization of the Operating Quadrant. The System Administration, Security Administration, and Service Monitoring and Control SMFs all exert some level of control over the more fundamental SMFs (bottom row of the triangle) in the quadrant. In some organizations, the triangular hierarchy depicted in Figure 2 may be collapsed to reflect organizational staffing levels and assignments, with some sharing of functions and responsibilities.



















Goals and Objectives

The goal of the Network Administration SMF is to provide and reference a solid foundation of processes for administering a network environment on a day-to-day basis. This entails managing and providing operational support for various elements within the production environment. The SMF’s objectives include providing planning and deployment services to expand existing network facilities, as well as support services to troubleshoot and repair faults in the network environment. Through effective implementation of the Network Administration SMF, IT organizations can expect to:

• Improve their deployment of network infrastructure.
• Improve troubleshooting processes and associated incident-management processes.
• Increase network reliability.
• Enhance availability of IT solutions and services.

Scope

A typical network consists of hardware—including cabling, routers, switches, hubs, physical servers, and other components—and the software or firmware that controls the manner in which the hard components are utilized. In the networking model described by Open Systems Interconnection (OSI), the typical IT infrastructure is constructed in layers, from basal components that are used by all services at the bottom of the stack, to specialized applications at the top.


The layers making up the OSI stack are (from the top, down):
1. Application
2. Presentation
3. Session
4. Transport
5. Network
6. Link (Data Link)
7. Physical

Network administration is typically involved with the first three layers of the stack, which mostly consist of hardware. There is some overlap between network and system administration at the transport level, which includes the linking and networking protocols that enable the transfer of data from one point to another. From the MOF perspective, management of such services as DNS, WINS, and DHCP provides the basic name resolution services required by fully featured IT services. Depending upon the organization, these core services may also be included as network service functions. Since DNS, WINS, and DHCP run on servers, network servers are sometimes included among the hardware components managed by the Network Administration SMF.


There is overlap between the Network Administration SMF and its sister SMFs within the Operating Quadrant. Network servers, such as DNS and WINS, require basic maintenance operations such as health monitoring (Service Monitoring and Control). In organizations running Microsoft Active Directory® directory service, there may be overlap in the processes applied to manage Active Directory itself and DHCP, which is tightly integrated with it.


The Network Administration SMF is also closely aligned with SMFs outside its quadrant. Upgrading network components is an intrinsic part of proactive network operations. These changes are controlled through the Change Management, Configuration Management, and Release Management SMFs within the Changing Quadrant. Similarly, although resolving user outages or other issues is the responsibility of the Incident Management SMF within the Supporting Quadrant, troubleshooting network-related issues is typically a specialty task that occurs within the Network Administration SMF. Some of these allied processes will be referred to or described within this SMF since they are central to a unified approach to managing a network.


This SMF provides generalized guidance for the configuration and maintenance of the hardware and software components of a network. Individual networks may vary widely in their overall architectures and component-level constituents. For this reason, guidance for specific hardware configuration and maintenance is presented as general recommendations within this document, and the reader is directed to review the specific manufacturer’s guidance for information about individual hardware components. Similarly, Microsoft has published individual POGs for DNS, DHCP, and WINS operating on the Windows Server platform.


Processes and Activities


This chapter provides a detailed discussion of the processes and activities that occur in the Network Administration SMF. The initial architecture, design, and development of a network infrastructure are beyond the scope of this SMF. However, network administrators should be completely familiar with their network’s architecture and configuration in order to properly operate, expand, and maintain it. The day-to-day operation of a static, healthy network occurs primarily within the Operating Quadrant, as defined in MOF. However, other typical activities, such as routine network upgrade, component replacement, or troubleshooting, involve a broader scope of SMFs. (This relationship between the Network Administration SMF and related SMFs will be described in more detail in a subsequent section.)

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