mod4quiz1

WINDOWS NT NETWORKING ENVIRONMENT

Networking capabilities are fully integrated into the Windows NT operating system. By providing both client and server capabilities, a computer running Windows NT can be either a client or a server in a distributed application environment. NT also provides file and print sharing capabilities.

There are two boundary layers in the Windows NT networking architecture model: transport driver interface (TDI) and network device interface specification (NDIS) 4.0.

Each network adapter card have one or more corresponding drivers. These drivers must be compatible with NDIS 4.0 to operate with computers running Windows NT 4.0, one or more protocols can be bound, independently, to one or more network adapter card drivers.

The initial communication channel between the protocol and the network adapter card driver is established through a process called binding.

Protocols govern communication between two or more host computers. Some protocols are commonly referred to as transport protocols. In the Windows NT network architecture, protocols are located above the NDIS 4.0 interface. Protocols communicate with network adapter cards through NDIS 4.0-compatible network adapter card drivers. Windows NT supports multiple protocols, bound simultaneously to one or more adapters.

DLC (data link control) is used primarily for accessing printers connected directly to the network and for accessing systems network architecture (SNA) mainframes.

NWLink IPX/SPX

NWLink is most commonly used in network environments where Microsoft clients need to access client/server applications running on Novell NetWare server, or NetWare clients need to access client/server applications running on computers running Windows NT.

NWLink supports the following networking APIs that provide IPC services.

Windows Sockets (WinSock) support existing NetWare applications written to comply with the NetWare IPX/SPX Sockets interface. WinSock is commonly used for communicating with NetWare Loadable Modules (NLMs). Customers implementing client/server solutions using NLMs can port them to Windows NT Server and still retain compatibility with their clients.
NetBIOS over IPX, implemented as NWLink NetBIOS, supports communication between a NetWare workstation running NetBIOS and a Windows NT-based computer running NWLink NetBIOS.

Configuring NWLink

Frame Types - A frame type defines the way in which the network adapter card formats data to be sent over a network. For computers running windows NT and NetWare servers to communicate, you need to configure NWLink on the computer running Windows NT with the same frame type as the one used by NetWare servers.

802.2 is newer than 802.3. If multiple frame types are detected in addition to the 802.2 frame type, NWLink defaults to the 802.2 frame type.

TCP/IP

TCP/IP is a standard, routable, enterprise networking protocol for Windows NT. It allows access to the Internet and its resources. The default gateway is where the IP sends packets that are destined for remote networks. If you do not specify default gateway, communications are limited to the local network. TCP/IP configuration values (IP address, default gateway, subnet mask) can also be configured automatically by using a DHCP server. TCP/IP includes following protocols : SNMP, WinSock, NetBT, TCP, UDP, ICMP, IP, and ARP.

IP address - is a logical 32-bit address that is used to identify a TCP/IP host. Each IP address has two parts: The network ID and the host ID. The network ID identifies all hosts that are on the same physical network. The host ID identifies a host on the network. Each computer running TCP/IP requires a unique IP address, such as 131.107.2.200. In this example, 131.107 is the network ID, and 2.200 is the host ID.

Subnet mask - is a network in a multiple network environment that uses IP addresses derived from a single network ID. Using subnets, an organization can divide a single large network into multiple physical networks and connect them with routers.

A subnet mask is used to block out a portion of the IP address so that TCP/IP can distinguish the network ID from the host ID. When TCP/IP hosts try to communicate, the subnet mask is used to determine whether the destination host is located on a local or a remote network. A sample subnet mask is 255.255.0.0. In order for computers to communicate on a network, they must have the same subnet mask.

Default gateway - For communication with a host on another network, an IP address should be configured for the default gateway. TCP/IP sends packets that are destined for remote networks to the default gateway, if no other route is configured on the local host to the destination network. If a default gateway is not configured, communication may be limited to the local network (subnet). A sample default gateway is 131.107.2.1.

NetBEUI

NetBEUI is a broadcast-based protocol used to support small LANs. It is not suitable for wide area networks because it cannot be routed. It uses more broadcast traffic than other protocols.

Connected-oriented and connectionless communication between computers.
Self-configuration and self-tuning.
Error protection.
Small memory overhead.

DHCP (Dynamic Host Configuration Protocol)

DHCP is a protocol that centralizes and manages the allocation of TCP/IP configuration information by automatically assigning IP addresses to computers that have been configured to use DHCP. Implementing DHCP eliminates some of the configuration problems and administration associated with manually configuring TCP/IP.

NetBIOS Name - is the computer's name assigned during installation. Can be determined by typing nbtstat -n at a command prompt and be 15 characters in length.

WINS (Windows Internet Name Service)

WINS is a NetBIOS Name Service that is designed to provide a flexible solution to the problem of locating NetBIOS resources in routed TCP/IP-based networks. It is a dynamic database for registering and resolving NetBIOs name-to-IP address mappings in a network.

I/O Manager, a component of the Executive Services, contains most of the Windows NT networking components. These components include network adapter cards and their drivers, network protocols, and file system drivers.

NDIS 4.0 defines the software interface used by protocols to communicate with network adapter card drivers. Any NDIS 4.0-compatible protocol can communicate with any NDIS 4.0 - compatible network adapter card driver.

The Server service supplies the connections requested by client-side redirectors and provides them with access to the resources they request.

In a typical distributed application, a computing task is divided into processes: front-end processes that require minimal resources and run on a client, and backend processes that require large amounts of data, number calculations, shared processing rules, or specialized hardware that run on a server. The server shares its processing power, carrying out tasks on behalf of clients.

Computers running Windows NT use IPC mechanisms to create client/server connections that support distributed processing. These include named pipes, mailslots, Windows Sockets, remote procedure calls (RPCs), network dynamic data exchange (NetDDE), and distributed Component Object Model (DCOM).

Network Number

Windows NT uses an IPX network number for routing purposes. This number is sometimes referred to as the external network number, and must be unique for each network segment.

Internal Network Number

Windows NT also uses an internal network number to uniquely identify the computer on the network for internal routing. This internal network number, also know as a virtual network number, is represented by an eight-digit hexadecimal number. By default, the internal network number is (00000000).

Routing Information Protocol (RIP)

RIP allows a router to exchange information with neighboring routers. A RIP router is a computer or other piece of hardware that broadcasts routing information, such as network addresses. As a router becomes aware of any change in the internetwork layout, it broadcasts the information to neighboring routers.