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
Lab
Workstation
Local
Router
Internet
Router
The
Internet
Workstation
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

Start
From Network
Neighborhood/
Properties.
TCP/IP Installation Steps
Choose Network/
Properties
Install Protocol
Add
TCP/IP protocol installed.
OK
Choose TCP/IP End

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 Start
From Network
Neighborhood/
Properties.
TCP/IP/
Properties
Proceed
Define TCP/IP properties

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

IP
Address
Subnet Mask
Gateway
DNS
TCP/IP Properties
TCP/IP
Properties
Advanced

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

DHCP
IP Address Assignment
Summarized
IP Address
Non-DHCP
Obtain IP
Address automatically
Specify IP Address
IP Address
123.345.678.90
Subnet Mask
255.255.255.0
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