CHAPTER 3

IMPLEMENTING NWLINK

Lesson 1: Introducing NWLink

Novel uses the Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocol at

its primary network protocol. NWLink is an IPX/SPX-compatible protocol developed by Microsoft

to allow Windows 2000 computers to communicate with the NetWare services.

Interoperability with NetWare

Windows 2000 provides protocols and services that allow you to integrate Windows 2000-based

networks with Novell NetWare networks, including the IPX/SPX/NetBIOS Compatible Transport

Protocol (NWLink), Windows 2000 Gateway Service for NetWare, and Windows 2000 Client

Service for NetWare. You can also migrate user accounts, groups, files and permissions from

NetWare to Windows 2000 using the Directory Service Migration Tool for NetWare provided

with Windows 2000.

The following list shows the services that enable Windows 2000 to be compatible with Novell NetWare

networks and servers.

IPX/SPX/NetBIOS Compatible Transport Protocols (NWLink). NWLink, and IPX/SPX

compatible protocol, is the fundamental building block for the NetWare-compatible services

on the Windows 2000 platform. Gateway Service for NetWare. Included with all varieties of

Windows 2000 Server. It enables a computer running Windows 2000 Server to communicate

at the application layer to computers running NetWare 3.2 or later server software.

Directory Service Migration Tool. This enables you to migrate user accounts, groups files, and

permissions from NetWare server to Windows 2000 Active Directory.

File and Print Services for NetWare. Allows NetWare clients using the IPX/SPX-compatible

transport to send print jobs over the network to Windows 2000 print server. File and Print Services

for NetWare is a separate product from Windows 2000 that does not require any changes to be

made to NetWare clients.

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Integrating NetWare 5.0 and Windows 2000 Servers

NetWare 5.0 uses TCP/IP as the native protocol, and IPX is not installed by Default. Running

mixed TCP/IP protocol and other protocols very sluggish and a lot of problems.

NWLink and Windows 2000

NWLink provides the network and transport protocols to support communications with NetWare file

servers, and must be installed if you want to use Gateway Service for NetWare or Client Service for

NetWare to connect to NetWare servers.

Because NWLink is Network Driver Interface Specification (NDIS) compliant, the Windows 2000-

based computer can simultaneously run other protocol stacks, such as TCP/IP. NWLink can bind

to multiple network adapters with multiple frame types. NWLink requires little or no initial client

configuration on small, nonrouted networks.

NetBIOS and Windows Sockets

NWLink supports two networking application programming interfaces (APIs): NetBIOS and

Windows Sockets (WinSock). These APIs allow Windows 2000-based computer to communicate

with NetWare clients and servers and any Windows-based computer that uses NWLink. Because

NWLink supports NetBIOS, it allows communications with all NetBIOS-based applications,

including Microsoft Systems Management Server, SNA Server, SQL Server, and Exchange

Server.

Microsoft (client) for Netware – IPX/SPX on Novell Servers so they can communicate. Novell

Client from Netware runs TCP/IP

NWLink Architecture

NWLink provides a comprehensive set of transport and network layer protocols that allow for

integration with the NetWare environment.

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======================================================================

Protocol Function Driver

======================================================================

IPX A peer-to-peer networking protocol NWLNKIPX.SYS

that provides connectionless datagram

services and controls addressing and

routing of packets of data within and

between networks

SPX and SPXII Provide connection-oriented transfer NWLNKSPX.SYS

Services

Router Information Provides route and router discovery NWLNKIPX.SYS

Protocol (RIP)

services

Service Advising Collects and distributes service NWLNKIPX.SYS

Protocol (SAP)

NetBIOS Provides compatible support with NWLNKNB.SYS

Forwarder Provides IPX router support NWLNKFWD.SYS

========================================================================

IPX

IPX is a peer-to-peer networking protocol that provides connectionless datagram transfer services

and controls addressing and routing packets of data within and between networks. With

connectionless, there is less overhead. Therefore, connectionless transmission is best when data

is generated in intermittent, short bursts.

Because IPX is a connectionless protocol, it does not provide for flow control or acknowledgement

that the receiving station has received the datagram packet. Instead, individual datagram packets

travel independently to their destination, and IPX assumes that they arrive intact without guarantee

that they arrive at their destination or that they arrive in sequence.

NWLink enables application programming for WinSock and remote procedure calls (RPCs) over

WinSock. IPX supports WinSock identifications for user by WinSock applications.

SPX

SPX is a transport protocol that offers connection-oriented services over IPX. Although connection-

oriented service requires overhead for session setup, once a session is established, this service

requires no more overhead for data transmission than connectionless service. Guarantees Delivery

of the Packets.

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SPX provides reliable delivery through sequencing and acknowledgments and verifies successful

packet delivery to any network destination by requesting verification from the destination on receipt

of the data. The SPX verification must include a value that matches the value calculated from the

data before transmission. By comparing these values, SPX ensures not only the data packet made

it to the destination, but that it arrived intact. SPX can track data transmissions consisting of a

series of separate packets. If an acknowledgment request brings no response within a specified

time, SPX retransmits the request as many as eight times. If no response is received, SPX

assumes the connection has failed.

SPX also provides a packet burst mechanism. Packet burst, also known a burst mode, allows

the transfer of multiple data packets without requiring that each packet be sequenced and

acknowledged individually.

CLASSROOM:

IPX/SPX requires the same frame type.

802.2 default communication type.

WINDOWS 95 set the frame type manually

802.2 is the Windows 98 standard.

SPXII

SPXII improves on SPX by allowing it to perform better on high-bandwidth networks. SPXII

improves on SPX in the following ways:

SPXII allows for more outstanding unacknowledged packets than SPX. In SPX, there cannot

be more than one outstanding unacknowledged packet at any time, whereas in SPXII, there can

be as many outstanding packets as negotiated by the networked peers at connection setup time.

SPXII allows for larger packets. SPX has a maximum packet size of 576 bytes, whereas SPXII

can use the maximum packet size of the underlying LAN. For example, on an Ethernet network,

SPXII can use 1518 bytes.

Router Information Protocol

NWLink uses Router Information Protocol (RIP) over IPX (RIPX) to implement route and router

discovery services used by SPX and NBIPX. RIP sends and receives IPX traffic and maintains

a routing table. The RIP code is implemented within the NWLNKIPX.SYS file. These computers

do not forward packets as routers do, but they use an RIP to determine where to send packets.

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CLASSROOM INFORMATION ON RIP:

· Rip has a 16 hop limit

· RIP router used Dynamic updates.

· OSPF is compatible with RIP

· RIP is very chatty, sends the entire table not just what you request.

· RIPI sends clear text

· RIPII encrypts and compresses.

· RIP always takes the quickest path not the cheapest.

Service Advertising Protocol

SAP is similar to a Browser Service.

Service Advertising Protocol (SAP) is the mechanism by which IPX clients collect and distribute

the names and addresses of services running on IPX notes. SAP clients use SAP broadcasts

only when bindery-based or Novel Directory Services queries fail. SAP clients send the

following types of messages:

SAP clients request the name and address of the nearest server of a specific type of broadcasting

and SAP GetNearestServer request.

SAP clients request the names and addresses of all services, or of all services of a specific type,

by broadcasting an SAP general service request.

CLASSROOM NOTES:

“BGP” Boarder Gateway Protocol

Unlimited hops

Owned by Cisco

Messenger to other routers, if local it sends the information, but if it is remote it forwards the

information to the next router.

Router IP Addresses:

10 .10. 10.

1-20 IP addresses x . x .x . x

2 Routers 1-20 reserved.

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To Display the Router:

Type route^print at the command prompt. 224.0.0.0 (Class D multicast)

· Route^add

· Route^delete

· Route ^change

See the route^? For all the other commands available.

TCP/IP How can you alter one of the layers?

You must bring your suggestion before the Engineers on the IEEE committee in the form of an

RFC. They will discuss, and test, and if it is approved it will become part of the standard

Protocol Stack. ATIN will not change Application/Transport/Internet/Network Layers, but

the internals of some of the layers may change.

NetBIOS over IPX

To facilitate the operation of NetBIOS-based applications on an IPX internetwork, NetBIOS

over IPX (NWLNKNB.SYS) provides standard NetBIOS services such as the following:

NetBIOS Datagram Services. Applications use NetBIOS Datagram Services for fast,

connectionless communications. Mailslots and user authentication make use of this service.

NetBIOS Session Services. NetBIOS Session Services provide connectionless-oriented,

reliable communication between applications. File and Print sharing rely on this service.

NetBIOS Name Service. Name management includes registering, querying, and releasing

NetBIOS names.

Forwarder

The Forwarder is a kernel mode component that is installed with NWLink. However, the

Forwarder is used only when the Windows 2000-based server is used as an IPX router

running Routing and Remote Access Service.

When no outgoing filters prevent the packet from being transmitted, the filtering component

passes the packet back, and the Forwarder component forwards the packet over the

appropriate interface.

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Lesson Summary:

NWLink is the Microsoft 32-bit implementation of IPX/SPX. IPX is a peer-to-peer

networking protocol that provides connectionless datagram transfer services and controls

addressing and routing of packets. SPX is a transport protocol that offers connection-

oriented services over IPX. A Forwarder component works with the IPX Router Manager

and the filtering component to forward packets on the best route.

Lesson 2: Using Gateway Service for Netware

Gateway Service for NetWare allows a Microsoft networking client (LAN Manager, MS-DOS,

Windows for Workgroups, Windows 95, Windows 98, Windows NT, or Windows 2000) to

access Netware server services through the Windows 2000 Server-based computer. You do

not change NT or Client users. You just need a common protocol. Gateway is a complete

translator. NWLink installed by default when you install Gateway Services.

Gateway Service for NetWare Overview

With Gateway Service for NetWare, you can create a gateway through which Microsoft client

computers without Novell NetWare client software can access NetWare file and print resources.

You can make gateways for resources located on Novell NDS trees as well as for resources on

servers with bindery security.

Understanding Gateway Service for NetWare and Gateways

Gateway Service for NetWare acts as a bridge between the NetBIOS protocol used by the

network using Windows and the NetWare Core Protocols used by the NetWare network.

When a gateway is enabled, network clients running Microsoft client software can access

NetWare files and printers without having to run NetWare client software locally.

For File access, the gateway server redirects one of its own drives to the NetWare volume

and then shares that drive with other Microsoft clients. The file gateway uses a NetWare

account on the computer running Windows 2000 Server to create a validated connection

to the NetWare server.

After the gateway connection is established, it is disconnected only if the computer running

Windows 2000 Server is turned off, if the administrator disconnects the shared resource or

disables the gateway, or if a network problem prevents access to the NetWare Server.

Logging off the computer running Windows 2000 Server does not, by itself, disconnect the

gateway.

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NOTE: Because requests from Microsoft networking clients are processed through the

gateway, access is slower than direct access from the client to the NetWare network.

Clients who require frequent access to NetWare resources should run the NetWare

clients software to achieve better performance.

Installing Gateway Service for NetWare

You have the option to install Gateway Service for Netware when you install Windows

2000 Server, or you can install GSNW later. You must be logged on as a member of

the Administrators group to install and configure Gateway Service for NetWare.

NOTE: Before you install Gateway Service for NetWare on a computer, remove any

existing client software that is compatible with NetWare Core Protocol, including NetWare

client software, from the computer.

Configuring Gateway Service for NetWare

When you first log on after Gateway Service for NetWare is installed, you are prompted

to set your default tree and context or your preferred server.

You can have either the default tree and context or a preferred server, but not both.

(In Novell DNS environments, you set a default tree and context). If you select a default

tree and context, you can still access NetWare servers that use bindery security.

** Page 63-64 try at home ***

Creating a Gateway

Before you can create a gateway to NetWare resources, the NetWare server must have a

group named NTGATEWAY and the user account with the necessary rights fro the resources

that you want to access. The NetWare user account can use must be a member of the

NTGATEWAY group. Only one group, so all have the same security. This can be a

security problem.

Enabling Gateways in Windows 2000

Creating a gateway is a two-step process. First, you enable gateway on the server

running Windows 2000 Server. When you enable a gateway, you must type the name

and password of the user account that has access to the NetWare server and is a

member of the NTGATEWAY group on that NetWare server. You need to do this

only once for each server that will act as the gateway.

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Activating Gateways

The second step is to activate a gateway for each volume or printer to which you want

to create a gateway. When you activate a gateway, you specify the NetWare resource

and a share name that Windows client users will use to connect to the resource. Dedicate

a server for your Gateway Server, it will be a very busy machine.

Security for Gateway Resources

Security for gateway resources is provided on two levels:

On the computer running Windows 2000 Server and acting as a gateway, you can set share-

level permissions for each resource made available through the gateway.

On the NetWare file server, the NetWare administrator can assign trustee rights to the user

account that is used for the gateway or to the NTGATEWAY group.

Connecting Directly to NetWare Resources

In addition to providing gateway technology, Gateway Service for NetWare enables users

working locally at a computer running Windows 2000 Server to access NetWare resource

directly, just as Client Service for NetWare provides this service to Windows 2000

Professional users.

Novell NDS trees (as well as NetWare Servers running bindery security) appear in the

NetWare or Compatible Network list in Windows Explorer.)

If you have a default tree and context, once you have logged on, you do not need to log on

again or supply another password to access any volume in your default tree. If you access

another tree, you are prompted to supply a full context (including user name) for that tree.

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Lesson Summary:

Gateway Service for NetWare allows a Microsoft networking client (LAN Manager,

MS-DOS,

Windows for Workgroups, Windows 95, Windows 98, Windows NT, or Windows

2000) to access NetWare server services through the Windows 2000 server.

Lesson 3: Using Client Service for NetWare

Microsoft network clients can access the NetWare server through the Windows 2000 Server

running Gateway Service for Netware. A Windows 2000-based computer can access

resources on the NetWare server as a client through the integrated Client Service for

NetWare component.

NetWare Connectivity

Client Service for NetWare provides client-based NetWare connectivity, and Gateway

Service for NetWare acts as a gateway through which multiple clients can access NetWare

resources. Both depend on and work with the NWLink protocol, which is automatically

installed with the redirector. Client Service for NetWare uses a subset of Gateway

Service for NetWare code. You need to go to each machine to load up, very tedious.

When a drive is mapped to a NetWare volume, the computer running Windows 2000

Professional uses a NetWare account to create a validated connection to the NetWare

server. You can also use the net use command line utility to specify the path

\\B\Volname.Orgunit.Org\Folder for the NetWare resource.

Choosing Between Client Service For NetWare

And Gateway Service for NetWare

If you intend to create or indefinitely maintain a heterogeneous environment containing both

servers running Windows 2000 and servers running NetWare, consider using Client Service

for NetWare. If you intend to migrate gradually from NetWare to Windows 2000 or if you

want to reduce administration, consider using Gateway Service for NetWare.

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Advantages of client Services for NetWare

Client Service allows for user-level security rather than share-level security. You can allow

users access to individual user home directories that are stored on NetWare volumes.

Client Service performs better than Gateway Service. Client Service communicates directly

with NetWare servers, avoiding, latency caused by request moving through a Gateway Service

for NetWare Server.

Disadvantages of Client Service for Netware

Client Service requires you to manage multiple user accounts for each user. For each user,

you must create and manage separate user accounts for both Windows 2000 and NetWare.

Client Service requires more installation and management overhead. With Client Service, you

must install and maintain additional Client Service software on each computer running

Windows 2000 Professional.

Client Service requires you to add IPX to your entire network. Servers running Windows

2000 and servers running NetWare 5.0 use TCP/IP as the native protocol. However, Client

service requires you to use IPX (through NWLink), and may require enabling IPX routing

throughout the entire network.

Configuring Client Service for NetWare

When you install Client Service for NetWare on Windows 2000 Professional, the NWLink

IPX/SPX/NetBIOS Compatible Transport Protocol is automatically installed. To install Client

Service for NetWare, you need Administrator rights to the computer running Windows 2000

Professional. NWLink not installed by default, must do this manually.

Lesson Summary:

Windows 2000 includes client software to support connections to servers running NetWare.
With the Client Service for NetWare in Windows 2000 and the Gateway Service for

NetWare in Windows 2000 Server, users can use file and print resources on servers

running NetWare.

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Lesson 4: Installing and Configuring NWLink

Windows 2000 Professional uses Client Service for NetWare and NWLink protocol to provide

connectivity between Windows 2000 Professional and servers running Novell NDS or NetWare

bindery-based servers. NWLink is the Windows component that includes the IPX/SPX protocol.

NOTE: To install Client Service for NetWare, you need Administrator rights to the computer

running Windows 2000 Professional.

Internal Network Number

The internal network number is used for internal routing purposes when the computer running

Windows 2000 is also hosting IPX services. When calculating the best possible route for

transmitting packets to a specified computer, multiple routes with the same route metrics can

present ambiguity to computer hosts. When you specify a unique internal network number,

you create a virtual network inside the computer. This allows for a singular optimum path from

the network to the services running on the computer.

Frame Type and Network Number

The frame type defines the way in which the network adapter, in a computer running Windows

2000, formats data to be sent over a network. To communicate between a computer running

Windows 2000 and NetWare servers, you need to configure the NWLink IPX/SPX/NetBIOS

Compatible Transport Protocol (NWLink) on the computer running Windows 2000 with the

same frame type as the one used by the NetWare servers.

=======================================================================

NWLink Frame Types

=======================================================================

Network Type Supported Frame Types

Ethernet Ethernet II, 802.2, 802.3, 802,2 Subnetwork

Access Protocol (SNAP)

Token Ring 802.5 and 802.5 SNAP

Fiber Distributed Data Interface 802.2 and SNAP

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Frame types define frame header and footer formats used by the different datalink layer

protocols.

During the Auto Detect process, NWLink tries each available frame type in the list for the

associated medium access types. For example, on an Ethernet network, Ethernet 802.2,

Ethernet 802.3, Ethernet II, and Ethernet Subnetwork Access Protocol (SNAP) are tested

to see which frame types NWLink can communicate with.

The external network number is a unique number that represents a specific network segment

and associated frame type. All computers on the same network segment that use a given frame

type must have the same external network number, which must be unique for each network

segment.

The IPX frame type and network number are set during the initial NetWare server configuration.

The Windows 2000 NWLink Auto Detect feature then detects the frame type and network

number that were configured on the NetWare servers. NWLink Auto Detect is the recommended

option for configuring both the network number and the frame type.

Occasionally, Auto Detect selects an inappropriate network number and frame type combination

for the adapter. Because Auto Detect uses the responses it receives from computers on the same

network segment, Auto Detect might select an incorrect frame type and network number if

computers respond with incorrect values.

The frame type and network number on Windows 2000 Professional need to match the frame

type and network number configured on the NetWare server. You can specify a frame type and

network number of 00000000 to have the network number of the network segment automatically

detected.

CAUTION: In most cases, you should not need to change the network number and frame type,

because Auto Detect should correctly detect the frame type and network number. If you choose

an incorrect setting, the client cannot connect to NetWare servers.

Configuring NWLink

To configure NWLink, you must first install the NWLink IPX/SPX/NetBIOS Compatible Transport

Protocol and be a member of the Administrators group. You can use the following procedure if you

want to bind NWLink to a different network adapter or to manually change the frame type. See

page 74.

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Lesson Summary:

IPX/SPX is a protocol stack that is used in Novell networks. The NWLink IPX/SPX/NetBIOS
Compatible Transport Protocol allows Windows 2000-based computers to communicate

with Novell networks. When you install Client Service for Netware on Windows 2000,

the NWLink IPX/SPX/NetBIOS Compatible Transport Protocol is automatically installed.

To configure NWLink, you must first install the NWLink IPX/SPX/NetBIOS compatible Transport
Protocol and be a member of the Administrators group.
The frame type defines the way in which the network adapter, in a computer running Windows 2000,

formats data to be sent over a network. The external network number is a unique number that

represents a specific network segment and associated frame type.

All computers on the same network segment that use a given frame type must have the same

external network number, which must be unique for each network segment.

DETERMINING SUBNETS

192. 10. 20. 1

Default

Subnet 11000000 00001010 00010100 00000001

C +11111111 11111111 11111111 00000000

Network ID 11000000 00001010 00010100 00000000

ANDing Formulas:

1 0 1

+1 + 1 + 0

___ ___ ____

1 0 0

To gain more networks steal from the Hosts. When you get IP address from InterNIC you only get on Network.

Subnet: Leftover 2 16th – 2 hosts

255. 0 . 0. 0 (Steal from the Lefthand to the Righthand)

8 bits or 2 8th – 2 = 255

Stealing Bits:

2 1 – 2 = 2

2 2 – 2

2 3 – 2

2 4 – 2

2 5 – 2

2 6 – 2

Another Question:

(Class A address)

255.255.0.0 (Class Subnet Mask)

8 bits (2 8th –2 = 256-2)

Another Question:

Class C address

5 Subnets, how many hosts?

X .X.X.X

NW Host

N.N.N.H

Bits Subnets

21 – 2 0

2 2-2 2

2 3 –2 6

2 4 –2 14

2 5 –2 30

2 6 –2 62

2 7 – 2 126

2 8 – 2 254

ANSWER: You need 5 subnets, so go down the Subnet chart to 5, but there is no 5 so go

to the 6 the next highest. Therefore 6 is 2 3 –2 . Look at 2 5-2 and you get 30 Hosts. So you

can have 6 subnets X 30 hosts/subnet = 180 total subnets.

Another Question:

Class B address. You need 1100 hosts/subnet mask? N.N.H.H.

Answer:

Bits Subnets

21 – 2 0

2 2-2 2

2 3 –2 6

2 4 –2 14

2 5 –2 30

2 6 –2 62

2 7 – 2 126

2 8 – 2 254

2 9 – 2 512

2 10 – 2 1024

2 11 – 2 2048

2 12 – 2

Answer:

You need 1100 subnets, so 1024 or 2 10 is not working you must go to 2 11th or

2048. 16 bits – 11 bits = 5, so you will have 30 subnets.

WORK SHEET MARCH 20, 2002

Bits Subnets

21 – 2 0

2 2-2 2

2 3 –2 6

2 4 –2 14

2 5 –2 30

2 6 –2 62

2 7 – 2 126

2 8 – 2 254

2 9 – 2 512

2 10 – 2 1024

2 11 – 2 2048

2 12 – 2 4094

2 13 – 2 8190

2 14 – 2 16382

2 15 – 2 32766

2 16 – 2 65534

128 64 32 16 8 4 2 1

2 7 2 6 25 2 4 2 3 2 2 2 1 2 0

128 192 224 240 248 252 254 255

Nomenclature default = /24 not /27 . 24 bits to make the subnet, I’m using 27. Don’s forget

that there can be a maximum of 32 bits. 32-27 = 5.

Hosts = 32 – 27 = 5 and look at the subnet chart = 30 for (2 5 – 2)

Steal 3 bits

6 Subnets

5 leftovers

Chart = 30 host/subnet

6 X 30 = 180 total hosts

Steal 3 bits to 8 = 128 + 164 + 32 = 224 Subnet Mask

Go from the Lefthand to the Righthand. Use the bottom chart to figure this

255.0.0.0/8 default subnet mask

/24 = take 16 bits both octets

255.255.255.0

16 bits 2 16 – 2 = 65,536-2 = 26534 subnets

254 hosts on each subnet because you have 8 bits leftover.

255.255.0.0/16 default (27-16 = 11)

There is an 11 bit difference.

(work left to right)

2046 subnets there is 5 leftover from the 8 bits = 30 hosts.

Default Subnet Mask for Class B = 255.255.0.0./16

22 bits – 16 default bits = 6 bits over look at the chart = 2 6 –2 = 62 subnets

Host = Difference = 6 Therefore, 62 hosts.

Subnet Mask = 6 bits, look at the lower chart go over from LH-RH by 2 bits = 128 + 64+ 32+ 16+8 +4 = 252 .

Therefore the subnet mask = 255.255.172.0

Default Subnet Mask for Class A = 255.0.0.0/8

21 bits – 8 = 13 bits leftover. Look at the chart and go down to 13 bits =

2 12 – 2 = 8190 subnets

Host = difference = 13

255.x.x.x

3 from the third octect = 128 + 32 + 16 = 224 for the subnet mask

SUBNET MASK FORMULA:

If the subnet you are looking for is 21, try this quick way to figure out the number, Adams way.

1. 128 64 32 16 8 4 2 1

255.0.0.0

2. 128 64 32 16 8 4 2 1

255.255.0.0

3. 128 64 32 16 8

255.255.248.0