LAN Protocols and TCP/IP

© N. Ganesan, Ph.D.

Module

A Preview of Major LAN Protocols

Major Protocols

• TCP/IP– De facto protocols of the Internet

• IPX/SPX– Used in Novell networks

• NetBEUI– A non routable local protocol

NetBEUI

• Supported by – Windows 9X, Windows NT, Windows

2000 and Windows XP • Non-routable protocol used for

setting a local LAN that does not require Internet access

• Can be used for an internal peer-to-peer or client-server network

IPX/SPX Compatible Protocol

• Used in Novell networks • Required for interoperability of

Windows network with Novell networks

• Routable protocol• IPX/SPX can be used for peer-to-

peer or client-server networking

TCP/IP

• An important protocol used widely on the Internet

• A routable protocol • Supports communication with UNIX

networks or any other network that work under the TCP/IP protocol– The base protocol in UNIX networks is

TCP/IP• Can be used for configuring peer-to-

peer as well as client-server networks of very large scale

A TCP/IP Application Scenario

Workstation

The Internet

InternetRouter

LocalRouter

Workstation

Lab

Configure the workstation for Internet access by Installing TCP/IP.

End of Module

Module

Basic TCP/IP Installation and Configuration

TCP/IP Installation and Configuration

• A two-step process• First, install the protocol

– With many modern OSs such as Windows XP, it is automatically installed

• Second, configure its properties– When TCP/IP is automatically installed, the

properties are set to be obtained from a DHCP server

– However, it is also possible to manually set the properties

TCP/IP Installation Steps

Choose Network/Properties

Install Protocol

Choose TCP/IP

Start

End

From NetworkNeighborhood/

Properties.

Add

OK

TCP/IPprotocolinstalled.

Accessing the Window for TCP/IP Properties

• Under different Windows operating systems the TCP/IP properties are accessed in different ways – The best and the most consistent way to

access TCP/IP properties Windows is to go through the Control Panel and then select the Network Icon

– Another way to access the properties is to go through Network Neighborhood

– Thereafter, select the network properties (Based on the NIC) and then then continue to select the TCP/IP properties

Accessing TCP/IP Properties Tab

Choose Network

TCP/IP/Properties

Start

From NetworkNeighborhood/

Properties.

Define TCP/IP properties

Proceed

TCP/IP Configuration Options

• Dynamic IP– A DHCP server must be present in the

network to issue dynamic IP– In a number of cases, the MAC address of

the client is registered to prevent unauthorized leasing of IP addresses to clients

• Static IP – Obtain the IP address specifications from

the network administrator

DHCP and TCP/IP Configuration

• Without a DHCP server– Requires the static assignment of IP

addresses and properties– The DHCP server need not reside on the

same subnet

• With a DHCP server– IP addresses etc. are automatically assigned

by the DHCP server– Select the appropriate option for the TCP/IP

address to be dynamically assigned by the DHCP server

TCP/IP Properties

Subnet Mask

Gateway

DNS

AdvancedTCP/IPProperties

IPAddress

Assignment of Properties for TCP/IP

• IP address• Subnet mask• Gateway address• DNS address

– Preferred– Alternate, if available

Alternate IP

• If the computer is used on another network as well, an alternate IP address may also be set– It can be a private IP address– Or, it could well be a static IP address

that is manually set

IP Addresses for Restricted Internal LANs

• For an internal network, only the IP addresses and the subnet masks need to be assigned– Note that subnet mask is not an IP address

• Such networks will not have access to the outside world meaning that it would not have a connection to the Internet

• There are also some IP addresses reserved for internal use that are known as private addresses– An example is 192.168.0.1

• For internal access, private IP addresses should preferably be used

Facilitating External Access

• A gateway address is required to facilitate external address

• A gateway is generally a router that directs the traffic to the next segment of the network that would eventually be linked through a series of hops over network segment to its destination

• There can be more than one gateway present in a network meaning that multiple gateway addresses can be entered in the TCP/IP properties window

IP Address Assignment Summarized

IP Address

Obtain IPAddress

automatically

Specify IP Address

IP Address123.345.678.90

Subnet Mask255.255.255.0

DHCP Non-DHCP

Gateway, DNS and WINS addresses

End of Module

Module

Advanced TCP/IP Settings

Accessing Advanced Properties

• Advanced properties can be accessed from the tab marked advanced

Advanced Properties of TCP/IP

• IP settings• DNS• WINS• Options

– Security related

IP and Gateway Settings

• Multiple IP addresses for the same NIC

• Multiple gateways

DNS

• Multiple DNSs• Search suffix order• Registering current computer with

the DNS server

WINS

• Setting multiple WINSs• Add LMHOST lookup• Set NetBIOS over TCP/IP to cater

for older applications that rely on NetBIOS

More on WINS

• WINS Configuration– This can be configured if there is a

WINS server on the network– The purpose of the WINS server is to

resolve Windows client names into IP addresses

– Windows names are not common in today’s environment as all computer names are based on TCP/IP

Options

• Set TCP/IP filtering by limiting access to certain ports for certain protocols

TCP/IP Implementation and Configuration End

Result

• The workstation is ready for Internet access

• Tasks possible– Access Internet

• Note: The computer may have a name generated by the OS such as Windows XP

The End