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Homework 3.2. What’s wrong with this picture?. Clients. Using 100TX. Hub. Hub. Clients. Hub. Hub. Client and Server Systems. Operating Systems Windows 95/98 Windows NT Workstation Windows NT Server Centralized Security and system policies Telecommunications Fax, mail, web.
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Homework 3.2 What’s wrong with this picture? Clients Using 100TX Hub Hub Clients Hub Hub
Client and Server Systems • Operating Systems • Windows 95/98 • Windows NT Workstation • Windows NT Server • Centralized Security and system policies • Telecommunications • Fax, mail, web
Network Servers • Network Operating Systems • Timesharing: splitting time between jobs • Multitasking: processing more that one job at a time • Parallel Processing: more than one cpu processing jobs • Load Balancing: sending jobs to different servers
Multitasking • Preemptive • OS can take over a task without cooperation of the task. • Nonpreemptive • The task decides if it will give up the processor.
Dedicated vs. Nondedicated • Dedicated Server • Server does server tasks only, it does not execute local programs (Novell) • CPU time is dedicated to server operations • Non Dedicated Server • The user has an interface to the OS on the server and can execute programs locally (Linux, Microsoft)
Software Components • Client • File access, Printing, Database access • Server • Disks, Printers, Programs • Redirectors • Handles client requests • Forwards a local request to LPT1: to print server • Accesses non local drive letters: F:\>, G:\>, etc
Server Software • Resource Sharing • File access: remote access to servers disks • Printer access: remote requests to local printer • Security and control • Which users can access the disk or printer? • Which users can write to the disk? • File locking when 2 users want to write to the same file. • Account for disk usage and printer paper
Server Administration • Managing Users • Privileges • Access to resources • Passwords • Location of users (address, email, etc.) • Time limits (8:00 AM to 5:00 PM) • Station limits (specific MAC address) • Resource load balancing
Novell Operating Systems • NetWare • NDS (Novell Directory Services) • Disk caching and distribution among servers • NDPS (Novell Distributed Printing Services) • Web Servers • Mail Services • Calendaring/Scheduling • Messenger service • Routing
Novell File Services • Logon Security • Authentication • Trustee Rights • Who can access what file/directory and what can they do with the file • Directory attributes • The types of operations on a file (read, write, shareable, copyable)
Novell Distributed Printing Services • Print spooling and control • Access by users to specific printers • Print load is transferred from client to server • Printer messages (out of paper, change form) are displayed on the server console. • Server handles multivendor printing protocols so client doesn’t need to. • Clients can share their printer through the server
Microsoft Network Operating Systems • Windows NT (includes Win2000, XP) • Single domain, single server, small workgroup • Single master, single server, multiple workgroups • Multiple master, multiple servers, several workgroups, accounts on multiple servers • Complete Trust • Several domains no master (workgroups trust each other)
Windows NT Services • File services • Similar to Novell, access, control, rights • Security, server maintains access lists • Printing • Clients or servers can share their local printers • Routing and Remote access • Other services • Messenger, Alerter, Browser
Interoperability • Gateway Services for NetWare • Handles NetWare requests for a domain • Client Services for NetWare • Handles NetWare requests for a workstation • File and Print Services for NetWare • Protocol converter • Directory Service Manager for NetWare • Allows Windows clients to access NDS • Services for Macintosh • Allows Appletalk service on the NT server
Appletalk Networks • Appleshare • Apple disk and printer sharing (Apple has it’s own file formats) • Zones (Apple’s workgroups/domains) • Security (each client maintains it’s own lists) • Appletalk servers can handle multiple protocols (TCP/IP, Appletalk, Microsoft)
UNIX (and Linux) Networks • Simple Client only to Server transformation • Can handle multiple protocols and services (Apple, Microsoft SMB, NFS) • Can be configured as a router/firewall • Well adapted to remote access
Peer to Peer • Simple to set up (almost all OS’s have built in peer to peer support) • Access lists are kept on each computer, there is no master server. • Useful for small (10 or less) workstations • Somewhat insecure
Interoperability • Multivendor environments • Servers can support different OS clients • Files transferred from different server types go through the client • Files transferred from different client OS’s go through the server • File formats may be different on each vendors operating system. File type conversion can be done on the server or client. • Authentication is almost always different between vendors. • Network Protocols may also be different between vendors
Server Security • Warnings: • When a server is placed on the network it is now wide open for attack. • All Network Operating Systems have bugs and security holes. • Always upgrade to the latest revisions of the OS • Limit the number of services provided by the server to the minimum needed for your particular application • Use firewalls as needed in the local area network
Network Types • What Protocol to use? • IPX • TCP/IP • Netbeui • Which Name Service? • DNS • WINS • LMHOSTS
Windows NT/95/98/2K Client • Pick a name (15 characters NetBios limit) • Or use WINS • Pick a workgroup or domain • Get networking working • Add appropriate protocols • Edit LMHOSTS (for TCP/IP) • Use Network Neighborhood or Find Computer to find the server
Workgroup/Domain • Workgroup • Login is on each client • Simple, minimal security • No dedicated server • Domain • Login is to the server over the network • Requires an NT Domain Server • High security, centralized usernames/passwords
Accessing Server Resources • Nbtstat to check netbios connectivity • UNC • universal naming convention • \\ntserver\users • \\ntserver\laser_office • net use • net use j: \\opie\bobw • net use lpt1: \\ntserver\laser_office
Web Services • Web Server (IIS on NT based systems) • Security Issues • File access • Database access • CGI programs • Counters • Data Entry
Mail Services • SMTP Support • POP and IMAP mail support • Novell Groupwise • Calendaring • Scheduling • Microsoft Exchange • Calendaring • Scheduling
Other Services • DATABASE Support • Microsoft SQL Support • Oracle Support • MySQL Support • Distributed License Service • Accounting of server and resource use • Disk space • Pages printed