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 Router Local Router Workstation Lab Configure the workstation for Internet access by Installing TCP/IP.

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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 Network Neighborhood/ Properties. Add OK TCP/IP protocol installed.

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 Network Neighborhood/ 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 Advanced TCP/IP Properties IP Address

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 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 IP Address automatically Specify IP Address IP Address Subnet Mask DHCP Non-DHCP Gateway, DNS and WINS addresses

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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

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