Network Operations

Network O/S setup

• 2 Major Types of Multitasking
1. Preemptive - O/S can take control of the processor without the task's cooperation
• Advantage of preemptive multitasking: CPU activity can be switched from local tasks to a network task
2. Non-preemptive (Cooperative)
• the task itself decides when to give up the processor
• no other program can run until the non-preemptive program gives up the control of the processor
• A Network O/S
• ties together all the PCs and peripherals in the network
• coordinates the functions of all PCs and peripherals in a network
• provide security for and access to database and peripherals in a network
• Client Software
• redirector
• process of forwarding requests is done by a redirector
• intercepts requests in the PC
• determines if they should be left alone to continue in the local PC's bus or redirected out to the network to another server
• designator
• a piece of software that manages the assignment of drive letters to both local and remote network resources or shared drives
• e.g. share drive in other PC, alphabet as a designator, such as G:
• when an association is made between a network resource and a local drive letter (mapping a drive), the designator takes care of remembering the path to the network resource.
• when users or applications access the drive, the designator substitutes the resource's network address for the drive letter before the request is sent to the redirector.
• peripherals
• redirectors can send requests to either computers or peripherals (e.g. LPT1: or Com1 can refer to local OR network printers. Just give these ports a path to the network device.
• Server Software
• makes it possible to SHARE resources (data, printers, modems, etc.) with workstations
• provides network security as well
• makes sure two users don't use the same resources at the same time.
• managing users - create, privileges, remove users
• network management tools to track network behaviour
• The server also
• Provides logon authentication for users
• Manages users and groups
• Stores management, control, and auditing tools for network administration
• Provides fault tolerance for protection of network integrity
• Windows NT Server
• When installing you must
• name the domain or workgroup
• name the server
• the 1st server installed in a domain must be installed as the primary domain controller (PDC), every domain is required to have one and only one PDC
• a backup domain controller
• keeps a copy of the domain's directory database
• authenticates logons
• can be an application server
• Configuring the network adapter card - default protocol for NT server is TCP/IP
• TCP/IP installation
• IP address
• logical 32-bit address to identity a TCP/IP host
• has two parts: network ID and host ID
• subnet mask - is used to mask a portion of the IP address so that TCP/IP can distinguish the network ID from the host ID - 255.255.0.0
• default gateway - (gateway = ROUTER) -  For communication with a host on another network, an IP host must be configured with a route to the destination network otherwise only communication on the local segment
• manual install - assign IP address, subnet mask and the default gateway
• automatic install - DHCP (Dynamic Host Configuration Protocol) service,
• when a DHCP server is configured on the network, clients that support DHCP (NT W/S & NT Server) can request TCP/IP configuration info (IP address, subnet mask, default gateway and so forth) from the DHCP server