Network and Telecommunications

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Network and Telecommunications

• 7. Lan Software

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Lan Software

• Application Software
• client apps vs. server apps (email or web
  server, database server)
• light vs. heavy network traffic
• user interfaces command line, menu-driven,
  GUI
• user (client) applications - word
  processing, spread sheets, compilers, email,
  web browsers, telnet/ssh, etc..
• server applications - backup software,
  license metering, ups monitoring, administrative
  tools (add users, monitor systems), network
  analysis tools
• NOS (network operating system)

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NOS

• peer-to-peer or client-server NOS
• commercial NOS (Novell Netware, banyan vines,
  etc..) vs.
• bundled NOS/OS (unix, MacOS, windows
  NT/2000/2003)
• provides file sharing, print and other services
  (email, web, modem)
• underlying protocols
• tcp/ip (unix, nt/2000/2003, internet)
• ipx/spx (novell), appletalk (macs) -past

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Mapping

• Mapping - key concept in networking.
  client/server.
• transparent to user (behind the scenes, in boot
  up scripts)
• PC - use drive letters to map from client to
  servers hard drive
• (h drive for example). Virtual drive letters.
  
• Windows - "net use" command.
• Novell - "map" command.

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Mapping II

• Unix/Mac - no drive letters.
• Mac uses the "chooser" network application to do
  mapping, and results appear as an icon on desktop
  (instead of drive letters).
• Unix systems use "mount" command and empty
  directories (mount points)
• to perform mappings.

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Mixed Lans

• Past
• Lans had one type of Hardware and one type of
  OS (like PC/Windows only)
• Today
• Clients mixed, servers can be mixed. Mixed
  hardware (mac, unix, pc)
• and mixed O.S. (unix/linux, windows 2000, nt,
  98, XP, 2003, Mac OS, etc..).
• Interopperability/Interconnectivity

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NOS from the Past

• IBM/Microsoft Lanmanager
• Banyan Vines
• And many others

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Novell Netware
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Basic Info

• Novell Netware- 3.0, 4.0, 5.0....
• used to be 1 product in pc market
• Started in 1983, commercial product
• ipx/spx original proprietary protocol
• Todays uses tcp/ip
• client/server
• clients - dos, windows 3.1, windows
  95/98/2000/NT/XP/2003, Mac, unix, etc...
• Uses map command to connect virtual drives

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Windows
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Basic Features

• NT - built-in, OS and NOS bundled, file and
  print sharing
• New Technology (NT) (includes windows server
  2000 and 2003), XP
• client/server primarily (peer-peer possible)
• clients - dos, windows 3.1, windows 95/98/2000,
  XP, nt clients, Mac, unix, etc...

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Back to Basics

• GUI-interface (like '95/98/2000) and commands
  (Dos Command Window)
• 2 versions workstation (for client) and server
  
• map drive letters (virtual drives)

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Protocols

• tcp/ip (internet, unix connectivity, wan)
• netbeui (compat. with lan manager)
• ipx/spx (novell netware connectivity)
• appletalk (mac connectivity)
• Tcp/ip is primarily used

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More Windows Info

• Installation
• manuals, disks, cdrom...gui based (follow
  instructions)
• both NOS on server and client, most on server
• addressing - ethernet address and tcp/ip
  addressing

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And more

• File System
• -FAT (like dos)
• -8.3 characters per filename, little
  security
• -NTFS (NT file system, more secure, faster,
  better)
• -255 characters per filename
• - many file/directory attributes/permissions,
  ACL (access control lists), ownership

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Windows Security

• Security
• account names and passwords
• login/logout
• file/directory permissions and attributes

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Windows Features

• Fault Tolerant Features (built-in)
• disk mirroring/disk duplexing, raid, ups
  monitoring

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NT Networking

• Domain
• collection of clients and servers in a given lan
  share same account info (user names, passwords,
  etc..)
• PDC (primary domain controller) and BDC (backup
  domain controller)
• copy "directory" to each other (replicated)
• Active Directory windows 2000/2003

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Windows Mapping

• File Sharing and Mapping
• Server
• control panel - icons to setup network, file
  sharing, services
• "My Computer" --gt click on any file/directory
  ----gt
• File pull down menu --gt select "sharing
• (or right click on folder and pick sharing)

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• Client
• connect to server (mapping) via
• a. Map Network Drive (Explorer Tool)
• uses virtual drive letter
• (right click on My Computer)
• b. command line (Command Prompt window)
• net use (see current
  mappings/virtual
  drives)
• net use K \\server\directory

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Unix Networking
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Unix Networking

• portable, scalable, modular, written in C (like
  NT)
• X windows (gui interface) or command line
• multiuser, multiprocessing, multithreaded,
  multi-tasking
• internet heavily based upon tcp/ip and unix
  servers (web, email, DNS)

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• ex. clam - time sharing for users (multiuser
  aspect)
• file server and print server to suns in 133
• file server for macs
• dns, web and email services
• 2 cpus (multiprocessing)

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Network Aspects

• NFS - Network File System (NOS)
• tcp/ip - protocol for networking
• client/server based, NOS built in with OS

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• No Drive Letters
• "mount" command - mapping (map to empty
  directories)
• attach to tree structure file system
• ex.
• client server

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• client
• mkdir /mountpoint
• mount server/usr/local/apps /mountpoint
• (or put into a file /etc/vfstab)
• Server
• use "share" command or put in /etc/dfs/dfstab

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Note

• all mount (mapping) commands are transparent to
  the user
• User never executes them, they are in start up
  files on the system which execute automatically
  on boot up
• The system and network administrator needs to
  know these details
• no use of virtual drives/drive letters

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Unix Commands and Files

• other network commands
• ping
• traceroute
• host
• netstat -i
• ifconfig

• Others network files
• /etc/hosts
• /etc/ethers
• /etc/services

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Netstat

• netstat
• gather network statistics/information, like
  number of
• input packets, number of output packets,
  collisions
• collision rate collisions / output
  packets x 100
• collisions rate lt 5 is good

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EXAMPLE!

• carp netstat -i
• Name Mtu Net/Dest Ipkts Ierrs Opkts
  Oerrs Collis
• le0 1500 carp 18979356 811 12094590
  160 456284
• thus collision rate 456284/12094590 x 100
  3.7

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ifconfig

• ifconfig - gather or configure network
  card/connection information
• Similar to ipconfig in windows
• Example
• crab ifconfig hme0
• hme0 flagltup,broadcast,running,ipv4) mtu 1500
• inet 165.230.111.194 netmask ffffffe0 broadcast
  165.230.111.223

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Summary

• 1. NOS General Info
• How is mapping performed (connecting client to
  server)?
• pc based nos - virtual drives (k g)
• macs - icons on desktop
• unix - empty directories attached in tree
  structure (mount point)

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• Basic mapping commands ?
• Windows - net use
• (net use K \\server\name\directory)
• (or use gui tool)
• mac - use chooser (gui application)
• unix - use mount command
• (mount servername/directoryname /mountpoint
  )

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More Summary Notes

• all mappings done behind the scenes, transparent
  to the user. Often done in boot up scripts
• on the server side, there are similar methods to
  "share" directories/files.
• A server doesnt share everything to the client,
  only selected directories/files.
• For example, on unix, you have a "share" command.
  On Windows and Macs, you can highlight a folder
  (directory) or a file, and the pick "share" from
  the file pull-down menu.

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Summary Continued

• 2. LAN Software
• 1. NOS (Windows, novell, unix/nfs,
  macs/appleshare..etc..)
• 2. application software

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Application Software

• Client Software
• Email (eudora, outlook, webmail), web browser
  (IE, Netscape, Mozilla), word processor (Word),
  spss, spreadsheets, etc
• located on server
• Typically the software is downloaded from the
  server to the client and runs on the client
  (exceptions imaging and thin clients)

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• Server Software
• Runs on Server Only
• Web Server Software (IIS or Apache), Email
  Servers Software (Sendmail, Postfix, Exchange)
• Database backend software (oracle)
• Other tools UPS monitoring software, backups,
  license management

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The End