2. Client-Server and Peer to Peer - I
• Client – Server
– Consist of one or more
clients and only one
server
– It is not possible for one
client to access shared
resources on another
client system
3. Client-Server and Peer to Peer - II
• Peer to Peer
– Computers on the
network can have access
to resources and data.
The computers act as
both clients and servers
– Computers are able to
communicate with each
other and share data
with other users
4. Types of Servers
• Servers are classified depending on the nature of work
• Types:
– File Server
– Print Server
– Mail Server
– Database Server
– FTP Server
– DNS Server
– DHCP Server
– WINS Server
5. Sharing Resources on Network
• Networking tasks includes sharing files and network
recourses and setting up network security
• User can share:
– Internet connection among multiple computers
– Several numbers of files, folders to avoid data redundancy
over Local Area Network
6. E-Mail Server
Often referred as mail server
Receives and delivers e-mails over the network
Maintains a storage area for e-mails
Employs a set of user defined rules that determine
the strategy for mail server to respond according to
the destination of a specific message
Most e-mail servers use Linux OS as they less
prone to viruses
7. Domain Name System (DNS)
• Two ways to resolve names: NetBIOS and DNS
• Technique used to provide standard naming conventions
for finding IP address configured hosts
• Uses hierarchical name space and distributed database
• Internet domains are classified into various categories
like “root” or the top most level of the Internet domain
namespace
• DNS is based on logical tree structure called domain
name space
8. DNS Namespace
• Categories of top-level domains:
– Organizational domain – e.g. .com
– Geographical domain – e.g. .uk
– Reverse domain – in-addr.arpa
9. DNS Server - I
• Contains information about the zones
• Zones are continuous portion of the domain name system
namespace
10. DNS Server - II
• A complete DNS name including the host
name and all of its domains is known as fully
qualified domain name (FQDN)
• A single DNS server contain all the host names
on the domain and their corresponding IP
address in the entire network is known as
authoritative DNS server
• No two machines should have the same FQDN
11. Name Resolution In DNS
• Name can be resolved in three ways: by
consulting locally stored text file called HOSTS,
by contacting a DNS server or by broadcasting
• As the database is centralized on the DNS
server, it is easy for the administrator to add
new entries just once rather than adding new
entries to each machines
• DNS server has to know about other DNS
servers where it can go for more information
12. Dynamic Host Configuration Protocol
(DHCP)
• Provides dynamic configuration of IP addresses on time
lease basis
• Provides information like IP address, default gateway,
DNS address and so on
• Backward compatible with BOOTP
• DHCP Server employs manual, automatic and dynamic IP
address allocation methods
• Reduces administration of a TCP/IP network
13. DHCP Server Responsibilities
• Address Storage and Management
• Configuration Parameter Storage and Management
• Lease Management
• Responding To Client Requests
• Providing Administration Services
15. IP Address Allocation
• DHCP provides temporary IP address with a particular
amount of time
• Methods of allocating IP address to the hosts:
– Manual allocation – IP addresses are manually entered
by server administrator
– Automatic allocation – Assigns the requesting client an
IP address from a pool of IP address
– Dynamic allocation – Makes use of IP address request
and permits process with time lease
16. WINS - I
• Windows Internet Name Service
• Maps Network Basic Input/Output System (NetBIOS)
computer names to corresponding IP addresses
• Was created to resolve the problems of broadcast-based
name resolution
17. WINS - II
• WINS Client Name Registration
– In WINS database NetBIOS, the WINS-enabled
client registers the names of processes running on
it.
– These client names should be renewed in the
WINS database
• WINS Client Name Renewal
– The renewal interval determines how long the server
stores the name registration as an active record in the
WINS database
18. WINS – III
• WINS Client Name Release
– NetBIOS names are released explicitly or silently
• WINS Client Name Resolution
– WINS server accepts client’s name resolution request
– A system name and a share name needs to be specified by
the user in order to connect to a network drive
19. WINS - IV
• WINS Client Behaviour
– Basic functions that a WINS client includes;
• Startup
• Plugging to subnet
• Extended shutdowns
• Establishing connections
20. Troubleshooting WINS
• Most WINS problems are not directly related to WINS
rather they are related to NetBIOS
• Nbtstat is used to troubleshoot NetBIOS name resolution
problems
• NetBIOS over TCP/IP (NetBT) resolves NetBIOS names to
IP addresses
21. NOS - I
• Network Operating System
• An Operating System for computer that can be
connected in network
• Organizes the activities of multiple computers across a
network
• Windows NT (New Technology)
– Contains advanced features for security, network support,
multitasking and user administration
– Basically two products; Windows NT Workstation and
Windows NT Server
22. NOS - II
• Windows 2000
– Improved version of Windows NT
– No need to configure or use NetBIOS
– Desktop and a server version of Windows 2000:
• Windows 2000 Professional
• Windows 2000 Server
– Active directory - Centralized storage area of information
about network resources related to users, applications,
files and printers
23. NOS - III
• Windows 2003 Server
– .NET version of the Windows 2000 server operating
system
– Windows Server 2003 editions:
• Small Business Server (Standard and Premium Edition)
• Web Edition
• Standard Edition
• Enterprise Edition
• Datacenter Edition
• Windows XP Professional
– Device support, user friendly and Remote Desktop
– Multiple users can log in and use the system without
logging out the previous users
24. NOS - IV
• Novell Netware
– Novell Corporation is a local-area network (LAN) operating
system
– Netware supported different types of LAN technologies
from Ethernet to IBM’s token-ring networks
• Linux
– An open source computer operating system
– Linux is based on UNIX operating system which was
designed to support networking