This document provides an overview of network operating systems (NOS) and Windows network concepts. It defines an NOS as a program that manages computer hardware and acts as an intermediary between the user and hardware. The two main types of NOS architecture are peer-to-peer and client/server. The most popular NOS are Windows Server and Linux Server. Windows network concepts include the differences between workgroup and domain networking models, an overview of Active Directory Domain Services (AD DS) and domain controllers.

1. Network Operating System (NOS)
and
Windows Network Concepts
NOS 1
Chapter 2

2. Network Operating System (NOS)
Definition
Characteristics of NOS
Types of Network Operating System (Architecture)
Popular NOS
NOS 2

3. Network Operating System (NOS)
Network + Operating System
Network
• is a communication path between two or more systems
Operating System
• program that manages the computer hardware
• provides a basis for application programs and acts as an
intermediary between the user and the hardware
• Types of Operating Systems
(Microsoft Windows, Linux and Unix, Mac OS etc)
NOS 3

4. NOS 4

5. NOS 5

6. NOS 6

7. Characteristics of NOS
Centrally manage network resources, such as programs, data & devices.
Secure access to a network.
Allow remote users to connect to a network.
Allow users to connect to other networks like the Internet.
Backup data and make sure it's always available.
Allow for simple additions of clients and resources.
NOS 7

8. Types of Network Operating System (Architecture)
Peer-to-peer NOS
• This system is not based with having a file
server or centralized management source.
NOS 8
Client/Server NOS
• It can be based on a client/server architecture in
which a server enables multiple clients to share
resources.

9. The most popular NOS
Windows Server
NOS 9
Linux Server

10. Windows Server
Windows servers are more powerful versions of their desktop
operating system counterparts and are designed to more
efficiently handle corporate networking, Internet/intranet
hosting, databases, enterprise-scale messaging and similar
functions.
Windows Server 2012 R2 is the latest release of Windows
Server, and focuses on cloud computing.
NOS 10

11. Windows
Microsoft products are regarded as the standard option for most
businesses.
Cost is also an important factor; license fees are expensive.
The more employees you have, the more expensive it will become.
Versions of Windows Server
NOS 11
Windows Server 2012 R2
Windows Server 2012
Windows Server 2008 R2
Windows Server 2008
Windows Server 2003 R2
Windows Server 2003
Windows Server 2000
Windows NT 4.0
Windows NT 3.51
Windows NT 3.5
Windows NT 3.1

12. Linux Server
A Linux server is a high-powered variant of the Linux open source
operating system that's designed to handle the more demanding
needs of business applications such as network and system
administration, database management and Web services.
Linux servers are frequently selected over other server operating
systems for their stability, security and flexibility advantages.
NOS 12

13. Linux
You can download, modify it and re-distribute it without spending
any money.
Linux is installed on over 95% of the world's best supercomputers
demonstrating that it is the fastest performing OS with the smallest
resource footprint.
No OS is perfect;
one of the major downsides of Linux is that as it is a lesser
known platform you will find it harder to administrators with the
skills to configure and support the system in-house.
NOS 13

14. Linux Server Distributions
The followings are Leading Linux server operating systems
(Top 10 Linux Server Distributions of 2017/18)
Source  serverwatch.com
• Ubuntu
• Red Hat Enterprise Linux
• Suse Linux Enterprise Server
• CentOS
• Debian
• Oracle Linux
• Mageia/Mandriva
• ClearOS
• Arch Linux
• Slackware
NOS 14

15. NOS 15
Which NOS is best for your business?
“Selecting the right platform is important for the health of your
business. It's worth building a test system running your preferred OS
so you can spot any issues and check security and performance prior to
going live, with minimal disruption for your users.”
David Barker is the technical director of 4D Data Centers

16. NOS 16

17. Windows Network Concepts
Networking models
The difference between workgroup and domain
Overview of Active Directory Domain Services (AD DS )
Overview of Domain Controllers (DC)
Windows Network Concepts 17

18. Networking Models
Two networking models:
• Workgroup
• Domain
Windows Network Concepts 18

19. Workgroup Model
All computers are equal
Also known as peer-to-peer
Each computer maintains own set of
• Resources
• Accounts
• Security information
Windows Network Concepts 19

20. Workgroup Model
(cont’d)
Windows Network Concepts 20
Table 2:1: Advantages and disadvantages of workgroup networks

21. Domain Model
Centralizes all shared resources
Single point of administrative and security control
Simpler to manage from administrative and security standpoint
Requires at least one domain controller (DC)
Windows Network Concepts 21

22. Domain Model (cont’d)
Windows Network Concepts 22
Table 2:2: Advantages and disadvantages of workgroup networks

23. Overview of AD DS
What Are AD DS Domains?
AD Structure
AD Objects
Windows Network Concepts 23
Overview of AD DS

24. Windows Network Concepts 24
Without AD
Partner
User
Company
password
10 Character
password
8 Character
password
12 Character

25. What is AD ?
A database (NTDS.DIT) on a Domain Controller
Based on X.500/LDAP
Uses Kerberos
Consistent synchronization across peer Domain Controllers
Extensible
Interoperates with other Domains /Forests
Windows Network Concepts 25

26. Windows Network Concepts 26
With AD DS
User
SSO with
Kerberos authentication

27. AD Structure
Domain
Tree
Forest
Trust
Federation
Windows Network Concepts 27

28. AD Structure (Domain, Tree)
Windows Network Concepts 28
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29. AD Structure (Forest)
Windows Network Concepts 29
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NB: The forest is the totality of all of your AD infrastructures

30. AD Structure (Trust)
Windows Network Concepts 30
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Forest Forest
Manual Trust

31. AD Structure (Federation)
Windows Network Concepts 31
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Federation
Federation allow different domains to access their resources in common
(i.e. it is not domain specific)

32. AD DS is composed of both physical and logical components
Windows Network Concepts 32
AD DS
Physical components Logical components
• Data store
• Domain controllers (DC)
• Global catalog server
• RODC (Read Only DC)
• Partitions
• Schema
• Domains
• Domain trees
• Forests
• Sites
• OUs (Organizational Units)

33. AD DS Domains?
AD DS requires one or more domain controllers
All domain controllers hold a copy of the domain
database which is continually synchronized
Windows Network Concepts 33
• The domain is the context within which user,
group, and computer accounts are created
• The domain is a replication boundary
• An administrative center for configuring and
managing objects
• Any domain controller can authenticate any logon
in the domain

34. AD Objects
User
Group
Computer
Sites, Site
Links
Windows Network Concepts 34
Organizational Unit (OU)

35. AD Objects (OUs )
Containers that can be used to group objects
within a domain
Create OUs to:
• Delegate administrative permissions
• Apply Group Policy
Windows Network Concepts 35
What Are OUs?

36. AD Objects (Sites and Site Links)
Windows Network Concepts 36
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37. Overview of Domain Controllers
What Is a Domain Controller?
What Is the Global Catalog?
The AD DS Logon Process
Windows Network Concepts 37

38. What Is a Domain Controller?
Servers that host the Active Directory database (NTDS.DIT) and SYSVOL
Kerberos authentication service and KDC services perform authentication
•Kerberos is a security mechanism built into the AD (not invented by
Microsoft but also used in other many authentication scheme as well)
•Advantage: it doesn't transfer the actual password over the network
•when user is logged on, it provides Ticket grant system (TGT)
Best practices:
• Availability: At least two domain controllers in a domain
• Security: RODC and BitLocker
Windows Network Concepts 38

39. What Is the Global Catalog?
Windows Network Concepts
39
Domain B
Domain A
Configuration
Schema
Domain A
Configuration
Schema
Domain B
Configuration
Schema
Domain B
Configuration
Schema
Global catalog:
Hosts a partial attribute set for other
domains in the forest Supports queries
for objects throughout the forest
Global catalog server

40. The AD DS Logon Process
Windows Network Concepts 40
DC1
SVR
1
WKS
1
The AD DS logon process:
1. User Account is authenticated to DC1
2. DC1 returns TGT back to client
3. Client uses TGT to apply for access to
WKS1
4. DC1 grants access to WKS1
5. Client uses TGT to apply for access to
SVR1
6. DC1 returns access to SVR1

41. Get start lab session by installing
Windows Network Concepts 41
 Virtualization software (Vmware or virtual box)
 MS Server 2012 R2
…..

42. Questions