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AppleTalk Networking Protocols

AppleTalk Networking Protocols
Apple Computers have had their own set of protocols for many years. More and more operating systems today now can communicate with Apple systems using Apple networking protocols.
  • ADSP - AppleTalk Data Stream Protocol is used to provide data stream service for sockets. The data stream is full duplex meaning communication may be sent both directions at the same time. Works at the OSI network model session layer.
  • AEP - AppleTalk echo protocol uses echoes to tell if a computer, or node, is available. It also measures the time it takes for eches to travel from the source computer (node) to the destination and back. Works at the OSI network model transport layer.
  • AFP - AppleTalk Filing protocol makes network files appear local by managing file sharing at the presentation layer. This protocol is build to top of ASP. AFP supports communication between different types of computers. Works at the OSI network model application and presentation layers.
  • AppleShare - Works at the application layer to provide services.
  • ARUP - AppleTalk update routing is a newer version of RTMP.
  • ASP - AppleTalk Session Protocol opens, maintains, and closes transactions during a session, while ADSP provides a full-duplex, byte-stream service between any two sockets on an AppleTalk Internet. Works at the OSI network model session layer.
  • ATP - AppleTalk Transaction Protocol provides a Transport Layer connection between computers. This protocol guarantees reliability by directing the transaction process and binding the request and response. Works at the OSI network model transport layer.
  • DDP - Datagram Delivery Protocol is a routable protocol that provides for data packet (datagram) transportation. It operates at the network layer of the OSI network model which is the same level the IP protocol in TCP/IP operates at. Works at the OSI network model network layer.
  • LAP - Link-Access Protocol is a set of data link layer protocols that support LocalTalk (LLAP), EtherTalk (ELAP), TokenTalk (TLAP), and FDDITalk. The LAP manager determines which LAP to connect for the correct upper level protocol.
  • NBP - Name-binding protocol translates addresses into user friently three part names. Works at the OSI network model transport layer.
  • PAP - Printer Access Protocol is a connection oriented service for managing information between workstations and printers. It is used to send print requests to printers.
  • RTMP - Routing Table Maintenance Protocol is used to update routers with information about network status and address tables. The whole address table is sent across the network. This protocol sends its information as broadcasts across the network every 10 seconds. Works at the OSI network model transport layer.
  • ZIP - Zone Information Protocol is used by AppleTalk routers co create a Zone Information Table (ZIT). The ZIT has a list of zone names which are associated with network numbers. This list is displayed in the Apple System's file Chooser. Works at the OSI network model session layer. 


Network LevelProtocols
ApplicationAFPAppleShare
Presentation
SessionADSPASPZIP
TransportAEPATPNBPRTMP
NetworkDDP
Data LinkLAP protocols



http://www.comptechdoc.org/independent/networking/protocol/protapple.html

IPX/SPX Protocols

IPX/SPX Protocols
IPX/SPX is a routable protocol and can be used for small and large networks. It was created by Novell primarily for Novell NetWare networks, but is popular enough that it is used on products that are not from Novell.
  • NCP - NetWare Core Protocol provides for client/server interactions such as file and print sharing. It works at the application, presentation, and session levels.
  • SAP - Service Advertising Protocol packets are used by file and print servers to periodically advertise the address of the server and the services available. It works at the application, presentation, and session levels.
  • SPX - Sequenced Packet Exchange operates at the transport layer providing connection oriented communication on top of IPX.
  • IPX - Internetwork Packet Exchange supports the transport and network layers of the OSI network model. Provides for network addressing and routing. It provides fast, unreliable, communication with network nodes using a connection less datagram service.
Network LevelProtocols
ApplicationNCPSAP
Presentation
Session
TransportIPXSPX
Network
Data LinkNDIS/NIC drivers

Other Network Support

  • ODI - Open Data-link Interface operates at the data link layer allowing IPX to work with any network interface card
  • RIP - Routing Information Protocol is the default routing protocol for IPX/SPX networks which operates at the network layer. A distance-vector algorithm is used to calculate the best route for a packet.
  • MHS - Message Handling Service by Novell is used for mail on Netware networks.  http://www.comptechdoc.org/independent/networking/protocol/protipxspx.html

Microsoft Protocols

Microsoft Protocols
Microsoft developed a suite of protocols around NetBIOS using NetBEUI for transport. The primary advantage of this protocol is that it is easy to configure and Microsoft claims that it runs faster. Microsoft has been switching to a wider use of TCP/IP in recent years, probably in support of larger organizational networks.
  • NetBIOS - Network Basic Input/Output allows browsing of network resources and handles basic functions of a Windows network. Two way acknowledged data transfer is used. It is a Microsoft protocol used to support Microsoft Networking. Works at the session layer. Controls the sessions between computers and maintains connections.
  • NetBEUI - NetBIOS Extended User Interface. Microsoft Protocol used to support Microsoft Networking. Provides data transportation. It is not a routable transport protocol which is why NBT exists on large networks to use routable TCP protocol on large networks. This protocol may sometimes be called the NetBIOS frame (NBF) protocol. Works at the Transport and Network layers. NetBEUI - The main protocol used for networking in the windows environment. NetBIOS Extended User Interface works at the transport layer and provides data transportation. It is not a routable transport protocol.
  • SMB - Microsoft Protocol used to support Microsoft Networking by providing redirector client to server communication. Works at the presentation layer.
Network LevelProtocols
ApplicationRedirector
PresentationSMB
SessionNetBIOS
TransportNetBEUI
Network
Data LinkNDIS/NIC drivers

Other Network Support

  • NBT - NetBIOS over TCP/IP refers to NetBIOS being transported by TCP/IP rather than NetBEUI defined by RFC 1002.
  • Redirector - Directs requests for network resources to the appropriate server and makes network resources seem to be local resources.
  • NDIS and NIC driver - NDIS allows several adapter drivers to use any number of transport protocols. The NIC driver is the driver software for the network card. 
http://www.comptechdoc.org/independent/networking/protocol/protmicro.html

TCP/IP Networking Protocols

TCP/IP Networking Protocols
The TCP/IP suite of protocols is the set of protocols used to communicate across the internet. It is also widely used on many organizational networks due to its flexiblity and wide array of functionality provided. Microsoft who had originally developed their own set of protocols now is more widely using TCP/IP, at first for transport and now to support other services.

TCP/IP by Layer

Link Layer

  • SLIP - Serial Line Internet Protocol. This protocol places data packets into data frames in preparation for transport across network hardware media. This protocol is used for sending data across serial lines. There is no error correction, addressing or packet identification. There is no authentication or negotiation capabilities with SLIP. SLIP will only support transport of IP packets.
  • CSLIP - Compressed SLIP is essentially data compression of the SLIP protocol. It uses Van Jacobson compression to drastically reduce the overhead of packet overhead. This may also be used with PPP and called CPPP.
  • PPP - Point to Point Protocol is a form of serial line data encapsulation that is an improvement over SLIP which provides serial bi-directional communication. It is much like SLIP but can support AppleTalk, IPX, TCP/IP, and NetBEUI along with TCP/IP which is supported by SLIP. It can negociate connection parameters such as speed along with the ability to support PAP and CHAP user authentication.
  • Ethernet - Ethernet is not really called a protocol. There are also many types of ethernet. The most common ethernet which is used to control the handling of data at the lowest layer of the network model is 802.3 ethernet. 802.3 ethernet privides a means of encapsulating data frames to be sent between computers. It specifies how network data collisions are handled along with hardware addressing of network cards.

Network Layer

  • ARP - Address Resolution Protocol enables the packaging of IP data into ethernet packages. It is the system and messaging protocol that is used to find the ethernet (hardware) address from a specific IP number. Without this protocol, the ethernet package could not be generated from the IP package, because the ethernet address could not be determined.
  • IP - Internet Protocol. Except for ARP and RARP all protocols' data packets will be packaged into an IP data packet. IP provides the mechanism to use software to address and manage data packets being sent to computers.
  • RARP - Reverse address resolution protocol is used to allow a computer without a local permanent data storage media to determine its IP address from its ethernet address.

Transport Layer

  • TCP - A reliable connection oriented protocol used to control the management of application level services between computers. It is used for transport by some applications.
  • UDP - An unreliable connection less protocol used to control the management of application level services between computers. It is used for transport by some applications which must provide their own reliability.
  • ICMP - Internet control message protocol (ICMP) provides management and error reporting to help manage the process of sending data between computers. (Management). This protocol is used to report connection status back to computers that are trying to connect other computers. For example, it may report that a destination host is not reachable.
  • IGMP - Internet Group Management Protocol used to support multicasting. IGMP messages are used by multicast routers to track group memberships on each of its networks.

Application Layer

  • FTP - File Transfer Protocol allows file transfer between two computers with login required.
  • TFTP - Trivial File Transfer Protocol allows file transfer between two computers with no login required. It is limited, and is intended for diskless stations.
  • NFS - Network File System is a protocol that allows UNIX and Linux systems remotely mount each other's file systems.
  • SNMP - Simple Network Management Protocol is used to manage all types of network elements based on various data sent and received.
  • SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
  • HTTP - Hypertext Transfer Protocol is used to transport HTML pages from web servers to web browsers. The protocol used to communicate between web servers and web browser software clients.
  • BOOTP - Bootstrap protocol is used to assign an IP address to diskless computers and tell it what server and file to load which will provide it with an operating system.
  • DHCP - Dynamic host configuration protocol is a method of assigning and controlling the IP addresses of computers on a given network. It is a server based service that automatically assigns IP numbers when a computer boots. This way the IP address of a computer does not need to be assigned manually. This makes changing networks easier to manage. DHCP can perform all the functions of BOOTP.
  • BGP - Border Gateway Protocol. When two systems are using BGP, they establish a TCP connection, then send each other their BGP routing tables. BGP uses distance vectoring. It detects failures by sending periodic keep alive messages to its neighbors every 30 seconds. It exchanges information about reachable networks with other BGP systems including the full path of systems that are between them. Described by RFC 1267, 1268, and 1497.
  • EGP - Exterior Gateway Protocol is used between routers of different systems.
  • IGP - Interior Gateway Protocol. The name used to describe the fact that each system on the internet can choose its own routing protocol. RIP and OSPF are interior gateway protocols.
  • RIP - Routing Information Protocol is used to dynamically update router tables on WANs or the internet. A distance-vector algorithm is used to calculate the best route for a packet. RFC 1058, 1388 (RIP2).
  • OSPF - Open Shortest Path First dynamic routing protocol. A link state protocol rather than a distance vector protocol. It tests the status of its link to each of its neighbors and sends the acquired information to them.
  • POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
  • IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.
  • Telnet is used to remotely open a session on another computer. It relies on TCP for transport and is defined by RFC854.

Bandwidth Control

  • BAP - Bandwidth Allocation Protocol is a bandwidth control protocol for PPP connections. It works with BACP.
  • BACP - Bandwidth Allocation Control Protocol.

TCP/IP by Function

Packaging and Low Level

  • IP - Internet Protocol. Except for ARP and RARP all protocols' data packets will be packaged into an IP data packet. IP provides the mechanism to use software to address and manage data packets being sent to computers.
  • SLIP - Serial Line Internet Protocol. This protocol places data packets into data frames in preparation for transport across network hardware media. This protocol is used for sending data across serial lines. There is no error correction, addressing or packet identification. There is no authentication or negotiation capabilities with SLIP. SLIP will only support transport of IP packets.
  • CSLIP - Compressed SLIP is essentially data compression of the SLIP protocol. It uses Van Jacobson compression to drastically reduce the overhead of packet overhead. This may also be used with PPP and called CPPP.
  • PPP - Point to Point Protocol is a form of serial line data encapsulation that is an improvement over SLIP which provides serial bi-directional communication. It is much like SLIP but can support AppleTalk, IPX, TCP/IP, and NetBEUI along with TCP/IP which is supported by SLIP. It can negociate connection parameters such as speed along with the ability to support PAP and CHAP user authentication.
  • Ethernet - Ethernet is not really called a protocol. There are also many types of ethernet. The most common ethernet which is used to control the handling of data at the lowest layer of the network model is 802.3 ethernet. 802.3 ethernet privides a means of encapsulating data frames to be sent between computers. It specifies how network data collisions are handled along with hardware addressing of network cards.

Transport and Basic Functions

  • TCP - A reliable connection oriented protocol used to control the management of application level services between computers. It is used for transport by some applications.
  • UDP - An unreliable connection less protocol used to control the management of application level services between computers. It is used for transport by some applications which must provide their own reliability.

Network Management

  • SNMP - Simple Network Management Protocol is used to manage all types of network elements based on various data sent and received.
  • ICMP - Internet control message protocol provides management and error reporting to help manage the process of sending data between computers. (Management). This protocol is used to report connection status back to computers that are trying to connect other computers. For example, it may report that a destination host is not reachable. This protocol is required for basic TCP/IP operations.
  • ARP - Address Resolution Protocol enables the packaging of IP data into ethernet packages. It is the system and messaging protocol that is used to find the ethernet (hardware) address from a specific IP number. Without this protocol, the ethernet package could not be generated from the IP package, because the ethernet address could not be determined. protocol is used to report connection status back to computers that are trying to connect other computers. For example, it may report that a destination host is not reachable. This protocol is required for basic TCP/IP operations.

Host Management

  • BOOTP - Bootstrap protocol is used to assign an IP address to diskless computers and tell it what server and file to load which will provide it with an operating system.
  • DHCP - Dynamic host configuration protocol is a method of assigning and controlling the IP addresses of computers on a given network. It is a server based service that automatically assigns IP numbers when a computer boots. This way the IP address of a computer does not need to be assigned manually. This makes changing networks easier to manage. DHCP can perform all the functions of BOOTP.
  • RARP - Reverse address resolution protocol is used to allow a computer without a local permanent data storage media to determine its IP address from its ethernet address.

Mail Protocols

  • SMTP - Simple Mail Transfer Protocol is used to transport mail. Simple Mail Transport Protocol is used on the internet, it is not a transport layer protocol but is an application layer protocol.
  • POP3 - Post Office Protocol version 3 is used by clients to access an internet mail server to get mail. It is not a transport layer protocol.
  • IMAP4 - Internet Mail Access Protocol version 4 is the replacement for POP3.

Multicasting Protocols

  • IGMP - Internet Group Management Protocol used to support multicasting. IGMP messages are used by multicast routers to track group memberships on each of its networks.

Routing Protocols

  • BGP - Border Gateway Protocol. When two systems are using BGP, they establish a TCP connection, then send each other their BGP routing tables. BGP uses distance vectoring. It detects failures by sending periodic keep alive messages to its neighbors every 30 seconds. It exchanges information about reachable networks with other BGP systems including the full path of systems that are between them. Described by RFC 1267, 1268, and 1497
  • EGP - Exterior Gateway Protocol is used between routers of different systems.
  • IGP - Interior Gateway Protocol. The name used to describe the fact that each system on the internet can choose its own routing protocol. RIP and OSPF are interior gateway protocols.
  • RIP - Routing Information Protocol is used to dynamically update router tables on WANs or the internet.
  • OSPF - Open Shortest Path First dynamic routing protocol. A link state protocol rather than a distance vector protocol. It tests the status of its link to each of its neighbors and sends the acquired information to them.                                                                                                                                    http://www.comptechdoc.org/independent/networking/protocol/protnet.html

Network Layers

Network Layers
The layered concept of networking was developed to accommodate changes in technology. Each layer of a specific network model may be responsible for a different function of the network. Each layer will pass information up and down to the next subsequent layer as data is processed.

The OSI Network Model Standard

The OSI network model layers are arranged here from the lower levels starting with the physical (hardware) to the higher levels.
  1. Physical Layer - The actual hardware.
  2. Data Link Layer - Data transfer method (802x ethernet). Puts data in frames and ensures error free transmission. Also controls the timing of the network transmission. Adds frame type, address, and error control information. IEEE divided this layer into the two following sublayers.
    1. Logical Link control (LLC) - Maintains the Link between two computers by establishing Service Access Points (SAPs) which are a series of interface points. IEEE 802.2.
    2. Media Access Control (MAC) - Used to coordinate the sending of data between computers. The 802.3, 4, 5, and 12 standards apply to this layer. If you hear someone talking about the MAC address of a network card, they are referring to the hardware address of the card.
  3. Network Layer - IP network protocol. Routes messages using the best path available.
  4. Transport Layer - TCP, UDP. Ensures properly sequenced and error free transmission.
  5. Session Layer - The user's interface to the network. Determines when the session is begun or opened, how long it is used, and when it is closed. Controls the transmission of data during the session. Supports security and name lookup enabling computers to locate each other.
  6. Presentation Layer - ASCII or EBCDEC data syntax. Makes the type of data transparent to the layers around it. Used to translate date to computer specific format such as byte ordering. It may include compression. It prepares the data, either for the network or the application depending on the direction it is going.
  7. Application Layer - Provides services software applications need. Provides the ability for user applications to interact with the network.
Many protocol stacks overlap the borders of the seven layer model by operating at multiple layers of the model. File Transport Protocol (FTP) and telnet both work at the application, presentation, and the session layers.

The Internet, TCP/IP, DOD Model

This model is sometimes called the DOD model since it was designed for the department of defense It is also called the TCP/IP four layer protocol, or the internet protocol. It has the following layers:
  1. Link - Device driver and interface card which maps to the data link and physical layer of the OSI model.
  2. Network - Corresponds to the network layer of the OSI model and includes the IP, ICMP, and IGMP protocols.
  3. Transport - Corresponds to the transport layer and includes the TCP and UDP protocols.
  4. Application - Corresponds to the OSI Session, Presentation and Application layers and includes FTP, Telnet, ping, Rlogin, rsh, TFTP, SMTP, SNMP, DNS, your program, etc.
Please note the four layer TCP/IP protocol. Each layer has a set of data that it generates.
  1. The Link layer corresponds to the hardware, including the device driver and interface card. The link layer has data packets associated with it depending on the type of network being used such as ARCnet, Token ring or ethernet. In our case, we will be talking about ethernet.
  2. The network layer manages the movement of packets around the network and includes IP, ICMP, and IGMP. It is responsible for making sure that packages reach their destinations, and if they don't, reporting errors.
  3. The transport layer is the mechanism used for two computers to exchange data with regards to software. The two types of protocols that are the transport mechanisms are TCP and UDP. There are also other types of protocols for systems other than TCP/IP but we will talk about TCP and UDP in this document.
  4. The application layer refers to networking protocols that are used to support various services such as FTP, Telnet, BOOTP, etc. Note here to avoid confusion, that the application layer is generally referring to protocols such as FTP, telnet, ping, and other programs designed for specific purposes which are governed by a specific set of protocols defined with RFC's (request for comments). However a program that you may write can define its own data structure to send between your client and server program so long as the program you run on both the client and server machine understand your protocol. For example when your program opens a socket to another machine, it is using TCP protocol, but the data you send depends on how you structure it.

Data Encapsulation, a Critical concept to be understood

When starting with protocols that work at the upper layers of the network models, each set of data is wrapped inside the next lower layer protocol, similar to wrapping letters inside an envelope. The application creates the data, then the transport layer wraps that data inside its format, then the network layer wraps the data, and finally the link (ethernet) layer encapsulates the data and transmits it.
Each network layer either encapsulates the data stream with additional information, or manages data handling or come part of the connection.
Layer Interaction
Without going into a great deal of technical detail, I will describe a general example of how these layers work in real life. Assuming that the protocol stack being used is TCP/IP and the user is going to use an FTP client program to get or send files from/to a FTP server the following will essentially happen:
  1. The user will start the FTP client program on the sending computer.
  2. The user will select the address (If the user selected a name, a description of DNS would need to be described complicating this scenario) and port of the server.
  3. The user will indicate to the FTP client program that they want to connect to the server.
  4. The application layer will send information through the presentation layer to the session layer telling it to open a connection to the other computer at a specific address and port. The presentation layer will not do much at this time, and the presentation layer is actually handled by the FTP program.
  5. The session layer will negociate through to the FTP server for a connection. There are several synchronization signals sent between the client and server computers just to establish the connection. This is a description of the sending of a signal from the client to the server:
    1. The session layer of the client will send a data packet (SYN) signal to the transport layer.
    2. The transport layer will add a header (TCP header) to the packet indicating what the source port is and what the destination port is. There are also some other flags and information that will not be discussed here to minimize complexity of this explanation.
    3. The network layer will add source IP address and destination IP address along with other information in a IP header.
    4. The datalink layer will determine (using ARP and routing information which is not discussed here for brevity) the hardware address of the computer the data is being sent to. An additional header (ethernet) will be added at this layer which indicates the hardware address to receive the message along with other information.
    5. The information will be transmitted across the physical wire (hardware layer) until the signal reaches the network card of the server computer. The signal may go through several hubs or repeaters.
    6. The FTP server will normally only look for ethernet frames that are matching its own hardware address.
    7. The FTP server will see the ethernet frame matching its address and strip the ethernet header information and send it to the network layer.
    8. The network layer will examine the IP address information, strip the IP header, and if the IP address matches its own, will send the information to the transport layer.
    9. The transport layer will look at the TCP port number and based on the port number and services being run, will strip the TCP header and send the information to the appropriate program which is servicing the requested port.
    10. At this point, the session layer in the FTP program will conduct a series of data exchanges between itself through all the lower layers to the client computer until a session is established. 

  6. At this point information may be sent through several FTP commands between the client and the server. Every transmission passes through the network layers from the application layer down to the hardware layer and back up the layers on the receiving computer.
  7. When the client decides to terminate the session layer will be informed by the higher layers and will negociate for the closing of the connection. 
http://www.comptechdoc.org/independent/networking/protocol/protlayers.html

Network Models

Network Models
When dealing with networking, you may hear the terms "network model" and "network layer" used often. Network models define a set of network layers and how they interact. There are several different network models depending on what organization or company started them. The most important two are:
  • The TCP/IP Model - This model is sometimes called the DOD model since it was designed for the department of defense It is also called the internet model because TCP/IP is the protocol used on the internet.
  • OSI Network Model - The International Standards Organization (ISO) has defined a standard called the Open Systems Interconnection (OSI) reference model. This is a seven layer architecture listed in the next section. 
 http://www.comptechdoc.org/independent/networking/protocol/protmodels.html

The CTDP Protocol Summary Version 0.6.0

The CTDP Protocol Summary Version 0.6.0

Introduction

This document is a summary of protocols that are used for networking, security, and other functions. This document only covers protocols. It does not cover services, network architecture, or media (method of hardware transport) associated with networking. The CTDP Networking Guide or Certification Guide is best used to learn about services or media.
Protocols are sets of standards that define operations and how they will be done. Without protocols there would be much confusion and there would be no standard to allow computers to communicate. Protocols are a set of defined reactions to given events. When a traffic light turns red, the defined reaction should be to stop. This is a simple form of a protocol.
Protocols are used for various purposes in the computer field. Protocols are mainly used to define networking standards although their application may extend beyond the scope of networking. Different uses of protocols include:
  • Networking - There are different suites (or stacks) of networking protocols. The most popular include TCP/IP, IPX/XPX from Novell, NetBEUI/NetBIOS from Microsoft, AppleTalk, and SNA. Different protocols within each suite of protocols may perform different functions at different levels (see network levels in the next section). These protocols are listed by both layer and function in this documentation. The protocol stacks include:
    • TCP/IP
    • IPX/SPX
    • Microsoft
    • AppleTalk
    • SNA
    • Other - Includes OSI, DLC and SNAP.
    The function of the network protocols include:
    • Packaging (IP)
    • Transport (TCP,UDP)
    • Network Management (ICMP, SNMP, ARP)
    • Host Management (RARP, BOOTP, DHCP)
    • Network Routing (BGP, EGP, IGP, RIP, OSPF)
    • Mail (SMTP)
    • Multicasting (IGMP)
    • Application (FTP, TFTP, NFS)
  • Security
    • Authentication
    • Encryption
    • Tunneling
  • Directory (LDAP) 
http://www.comptechdoc.org/independent/networking/protocol/

Networking Section Introduction

Networking Section Introduction
This section contains networking documentation and networking information contributed by members of the CTDP. There is much TCP/IP information and documentation in this section. Currently this section contains three documents:
  • The CTDP Networking Tutorial - Describes networking from the ground up, including how routers and firewalls work along with descriptions of the various network protocols. The Network Tutorial is available in PDF form It includes the following information:
    • Network Topologies such as ring, star, and bus.
    • Network cabling including definitions of and/or descriptions of baseband, broadband, twisted pair, coax cable, and fiber optic cable. Includes twisted pair category descriptions.
    • Network architectures such as ethernet, token ring, ARCnet, AppleTalk, and FDDI.
    • Protocol stacks such as TCP/IP, IPX/SPX, NetBEUI/NetBIOS, and SNA.
    • TCP/IP addressing
    • TCP/IP protocols such as ARP, RARP, IP, TCP, UDP, ICMP, IGMP, DNS, BOOTP, DHCP, RPC, NFS, SMTP, and SNMP.
    • TCP/IP functionality and services including routing, firewalls, gateways, IP masquerading, domain name service, dynamic host configuration protocol, broadcasting, multicasting and dynamic routing.
    • Dynamic routing protocols including RIP and OSPF.
    • Virtual private networking including information about IPSec, PPTP, L2TP
    • Definition of repeaters, bridges, and routers.
    • Fault tolerance including redundant array of inexpensive disks (RAID) disk striping and disk mirroring.
  • Network Certification Reference - The second document is a brief set of information and terms for those learning networking in a certification effort.
    • OSI network model
    • Network topologies, physical media, and wireless media.
    • Modems and their operation including ISDN modems.
  • Network Protocol Summary - This tutorial provides a handy summary of various network protocols by category.

Weblinks

The weblinks section contains several useful weblinks including links to internet agencies, TCP/IP documentation, and more. A link to the RFC listings at Ohio State's website is provided here. 

http://www.comptechdoc.org/independent/networking/index.html

Basic Computer Terms

Basic Computer Terms
  • Bit - A binary unit of data storage that can only be a value of 0 or 1.
  • BIOS - BIOS stands for Basic Input/Output System and it is a low level program used by your system to interface to computer devices such as your video card, keyboard, mouse, hard drive, and other devices.
  • Boot - A term used to describe what happens to a computer when it is turned on, the operating system begins to run, and then the user is able to use the computer successfully.
  • Byte - 8 bits of data which has a possible value from 0 to 255.
  • CD-ROM disk - A disk with about 640Mb of storage capacity which are more commonly read than written to.
  • CD-ROM drive - The hardware component that is used to read a CD-ROM or write to it.
  • Crash - A common term used to describe what happens to a computer when software errors force it to quit operating and become unresponsive to a computer user.
  • Driver - A specially written program which understands the operation of the device it interfaces to, such as a printer, video card, sound card or CD ROM drive. It provides an interface for the operating system to use the device.
  • File - A collection of data into a permanent storage structure. Stored on a permanent storage media such as a computer hard drive.
  • Firmware - Software written into permanant storage into the computer.
  • Floppy disk - A low capacity storage media which can be written to as easily as it is read.
  • Floppy Drive - The hardware component that is used to read or write to a floppy disk.
  • Hardware - Describes the physical parts of your computer which you can physically touch or see such as your monitor, case, disk drives, microprocessor and other physical parts.
  • Internet - A network of networks which incorporate a many organizations, physical lines, the ability to route data, and many services including email and web browsing.
  • ISP - Internet Service Provider is an organization that provides the ability to connect to the internet for their customers. They also usually provide additional services such as e-mail and the ability to host web sites.
  • MIME - multipurpose internet mail extension
  • Memory - Used to provide the temporary storage of information function.
  • Network - A general term describing to the cables and electronic components that carry data between computers. It is also generally used to refer to the server computers that provide services such as printing, file sharing, e-mail, and other services.
  • Operating System - The core software component of a computer providing the ability to interface to peripheral and external devices along with program functions to support appllication programs.
  • Parallel - A data transmission method where data is sent on more than one line at a time. This may be any number of bits at a time, but is usually one word at a time (two bytes) or possibly three bytes at a time.
  • Protocols - A standard method used for communications or other internet and network functions.
  • Security flaw - A software bug allowing an attacker a method to gain anauthorized access to a system.
  • Serial - A data transmission method where data is sent on a single line and one bit is sent at at a time. This is similar to a line which one item must come one after another
  • Software - Describes the programs that run on your system.
  • SPAM - A term used to describe junk and unsolicited e-mail.
  • Storage Media - A term used to describe any magnetic device that computer data can be permanently stored on such as a hard drive or floppy drive.
  • URL - Uniform Resource Locator is the term used to describe a link which points to a location of a file on the internet.
  • Virus - A program that runs on a system against the owner's or user's wishes and knowledge and can spread by infecting files or sending itself through e-mail
  • Vulnerablity - Software errors that allow some kind of unauthorized access when they are used or exploited.
  • Word - Two bytes or 16 bits of data with a possible unsigned value from 0 to 16535.
  • Worm - A term used to describe an unwanted program that uses system or application vulnerabilities to infect a computer without the user doing anything but connecting to an infected network. 

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Summary

Summary
There are several things you should do to make your system more secure, and keep it performing better.:
  • Change your file view settings on Windows systems so you will see all file extensions.
  • Always run anti-virus software and keep the virus definitions updated at least twice per week.
  • Never connect to the internet unless you are using a personal firewall or are behind an organizational firewall on a private network.
  • Never open e-mail attachments without being sure of who sent them. Keep the following in mind:
    • E-mail addresses can be faked by virus programs.
    • New viruses may not be recognized by your anti-virus software.
  • Patch your operating system regularly. This will reduce your vulnerabilities to worms and hackers. See the Applying the latest patches to your Windows 2000 Operating system to prevent viruses and worms article for more information.
  • Patch your applications regularly especially Microsoft Office. See the Preventing Viruses in Microsoft Office® Products article for more information.
  • Perform regular backups of your data.
  • Make an emergency boot disk to enable you to restore your system in the event of file corruption or a virus that makes it unable to boot.
  • Avoid installing unneeded applications and always be sure any free programs do not have a hidden purpose. 
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Making a Boot Disk

Making a Boot Disk
Open the Windows backup program on Windows 2000 by selecting Start, then Programs, then Accessories, then System Tools, then Backup. The backup utility will start as shown below.

Backup 
 
When the Welcome tab is displayed in the Backup program, click on the "Emergency Repair Disk" button near the bottom. When the "Emergency Repair Diskette" dialog box appears select the checkbox next to "Also backup the registry to the repair diretory..." and click OK. You will need to put a blank floppy into your floppy disk drive.

Insert Floppy
 
  Once the process is complete, you should label the floppy disk with the current date and the name of the system you are making the disk for.
If you ever get into a situation where your system will not boot, you can use this disk to help you recover your system. This is a somewhat technical process but it begins by pressing the F8 function key while the system is booting which will provide some advanced booting options, one of which will allow you to try to boot using your emergency repair disk. It is usually much easier to recover a system that has an emergency repair disk.

Successful Save 
 
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Removing Viruses

Removing Viruses
Removing viruses can be risky to your operating system and may cause you to need to re-install your operating system. If you do not feel comfortable with the instructions in this section, you should get a computer professional to do the job. For more information read Applying the latest patches to your Windows 2000 Operating system to prevent viruses and worms. It contains information about how to remove viruses along with other useful information.

Virus Removal Procedure

  1. Be sure you have good backups of your data along with an emergency boot disk for your system.
  2. Determine what viruses you have on your system.
    1. Install a virus scanning program if you do not have one already installed. Use the product of your choice. It is wise to read product reviews.
    2. Be sure your virus definitions are up to date. Connect to the internet and download the latest virus definitions from the company that created your anti-virus software.
    3. Configure your virus scanner not to remove any viruses but only detect them. You do not want to remove the virus(es) immediately since some viruses may infect files that your system requires to run. If these files cannot be cleaned by the anti-virus program, they may be deleted or quaranteened. If this happens you may not be able to run your system again.
    4. Scan for viruses but do not remove them. Note: Some viruses will stop your virus scanner from operating. If this is the case you will probably need the help of a computer professional. If you have a virus that stops your virus scanner then you will need to either share the drive across a network and scan it from another computer or remove your hard drive and place it into another computer as a second hard drive, then scan your hard drive.
  3. Learn about the viruses you have and how to remove them. - Go to the web site of the organization that created your anti-virus software. The Symantec security response site is a good site to find information about specific viruses and they provide virus removal tools.
  4. Remove the viruses.
    1. Many viruses have a removal tool which can be used to remove the virus. If there is a removal tool, download it and use it to remove the virus.
    2. If there is no removal tool, you will need to follow the manual removal instructions. You may need to manually delete virus files and edit your system registry. The removal instructions will tell you how to do this, but some people may not feel comfortable doing this without the help of a computer professional.
    3. If the manual instructions indicate that you should let your virus scanner remove the virus, then remove all viruses that you can with virus removal tools then run the virus scanner with it configured to remove all viruses.                                     http://www.comptechdoc.org/basic/basictut/

Spam

Spam
Spam is unsolited junk e-mail sent to large numbers of e-mail addresses. It is used to promote some product or service and many spam e-mails are pornographic in nature.

Spam Prevention

Unfortunately there are not very many good ways of preventing spam other than keeping your e-mail address secret. It should be kept at a level of security somewhere between your phone number and your social security number. You should be careful about who you give your email address to. Many companies will sell your email address to spam lists, thus making it available to spammers.

I currently use three email accounts as follows.
  • The first account is the one I give to personal acquaintances.
  • The second account I give to companies that have a privacy policy that I am fairly certain won't sell my e-mail address.
  • The third account, I give to companies that I believe I cannot trust to sell my information. I don't worry if these companies can contact me. 
I expect to change the third account pretty often, but hopefully the first two will last several years without much spam. The third account may be through a free internet email account service such as hotmail or yahoo.

Managing Spam

Besides keeping your e-mail address secret, the next best spam relief are programs that help you manage spam. Spam can be filtered at the mail server with some programs or they can be a program that plugs into your e-mail client program such as Outlook or Outlook Express. Basically these types of programs filter spam based on several characteristics such as:
  • The subject line
  • The address of the sender
  • Some programs scan the message content and consider length or wording
Unfortunately none of these scanning methods are 100% accurate although some claim to achieve success rates into the upper 90 percentile. What most of these programs do is to create folders for "friendly" mail or "unfriendly" mail. The friendly mail is put into one folder, unfriendly mail is put into a second folder and there may be a third folder for unknown mail. Unfriendly mail is automatically deleted after some period of time. The capabilities and handling of the mail will vary from program to program. Some that I have considered using include:
  • Qurb
  • I Hate Spam
  • Spam Assassin
There are various opinions about what works when fighting spam. For more information and articles about how to fight spam you can find links to articles at Computer Technical Tutorials Spam .

Spam for Webmasters

If you are a webmaster, spammers will send spam to your domain by sending it to general possible accounts such as administration@yourdomain.com. One way to prevent this is to configure your account with your hosting provider not to respond to undeliverable emails and just automatically delete them. This is called a "::blackhole" setting. The only problem with this is that spammers will still use your bandwidth that you pay for to send you their junk, even though your server deletes them. As spam gets more excessive, it may increase bandwidth costs for webmasters thus discouraging some sites from operating.

Why Spam Should be Illegal

When you connect to the internet, you are paying for a specific service for your use. This service costs a specific amount of money and provides a certan connection speed to the internet. This connection speed indicates your bandwidth. The greater the connection speed, the higher the bandwidth. The higher speed connections cost more money. At this poiint you have paid for the privilege of surfing the internet with your web browser, sending and receiving e-mail, and other activities. The speed at which you can do this is limited by your bandwidth and how fast you can click pages or send or receive e-mail. Consider the Following diagram: 

Internet Connections 
 
 
Each person has a connection to the internet. If the person on the right chooses to use their connection to send e-mail or junk e-mail (spam), that is their choice. They are paying for their connection and they are willing to use it in that manner.
If the person on the left does not want to receive spam, but wants to read personal e-mail and surf the internet, they are willing to receive only personal e-mail. If someone is sending them a lot of spam, they will need to wait for the junk e-mail to be delivered before they can read much of their personal e-mail. They are an unwilling participant regarding the unsolicited e-mail they are receiving. Not only is their connection being used by someone else, but it will take them additional time to sort the mix of e-mail out to get to the mail they want to read. If the receiver had willingly stated that they were interested in receiving the advertisements, it would be another matter.
Of course the sender of the spam is not using all the spam receiver's internet connection, but the spam receiver does not get the opportunity to use their connection in the way they fully intended even though they were the one paying for it. This is the same as stealing even though the effective amount may be small. Imagine, how rich you could be if you could only steal a fraction of a cent per day or week from everyone who uses the internet. That's why spam should be illegal.
Someone may argue that spam is the same as junk mail sent through the postal service so why would it be stealing. This is not true since the sender of mail through the postal service pays for the cost of both pickup and delivery. On the internet, the sender pays for the cost of pickup and the receiver pays for the cost of delivery.
 

The Real and Permanent Solution to Spam and Viruses

Unfortunately a permanent and good solution will take years to implement. A new mail protocol (method of sending e-mail) must be developed by the internet community and then e-mail servers must be modified to handle that protocol. The changing of the e-mail servers will take the most time.
I believe all e-mail should be digitally signed by the sender in order to be delivered. This way the sender cannot be faked and everyone must take responsibility for their own e-mails. However to get this to work right someone must find a way to keep viruses from being able to digitally sign your e-mails for you automatically. A bug in your e-mail client may allow a virus to digitally sign your e-mails causing this type of solution to be ineffective, however, in this case, there would be no doubt as to who has the virus.
 

Some Proposed Solutions that Won't Work

  • Paying for each e-mail sent - This solution will not work because it forces people to pay for services that they have already paid for. Additionally it will not prevent spammers from using poorly configured servers to send spam illegally. It will most likely force victims (those who get viruses and administrators who have spammers illegally relay mail through their mail servers) to pay for the additional e-mail. On the brighter side, it may force more administrators to lock their systems down better and force computer users to be more careful about getting viruses. If this were done, I would think it would make the most sense to allow a limited amount of email to be send on a monthly basis for free.
  • Reverse address to name lookup - Some ISP's want to use a check that looks at the address the mail came from and determine the name of the server. If the name does not match the name advertised by the sending mail server, then the e-mail is assumed to be spam and dropped with no notification to the sender. Not only does this violate the rules (protocol) governing the internet for sending e-mail, it will cut down or eliminate the ability for web based programs to automatically notifify users at some websites about events. For instance forum sites will notify when someone has posted an answer to a question. If the user's ISP uses reverse lookup, the user may never see the email from the forum website where they asked a question. 

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E-mail Viruses

E-mail Viruses
Viruses that spread through e-mail have a common method of spreading. This page will discuss how common e-mail viruses currently spread. 

The Virus Lifecycle

Viruses begin their life when someone releases them on the internet. They begin to spread. At this early stage of their lifecycle, no one is aware of their presence. As the virus becomes more widely spread, someone will recognize an abnormal problem with their system and investigate. Eventually a computer expert will conclude that a virus exists and notify companies that write anti virus software. The companies will research the virus and come out with an update to their database of viruses that includes information about the new virus and has information about how to recognize it. They may also release a tool that can be used to automatically remove that virus from computer systems.

Therefore the cycle is:
  1. Release - The virus is released.
  2. Recognition - Someone recognizes the virus.
  3. Virus recognition database update - Antivirus programs will now recognize the virus.
  4. Antiivirus update and removal tools
The time between step one and step three above can be significant. During this time you are vulnerable to getting the virus because your anti-virus software will not recognize it as a virus. This is why you should be careful about the e-mail attachments that you open, even if you are actively running anti-virus software.

How Viruses Work

  1. When a victim of a virus double clicks on an infected attachment, the virus will run.
  2. The virus will modify the victim's system so it will always be active when the system is turned on.
  3. The virus will scan the victim's address book in their e-mail client program such as Outlook or Outlook Express.
  4. In the past, viruses would then mail themselves to addresses found in the victim's address book. But today many viruses choose random recipients and senders from the victim's address book. This means that although the e-mail is sent from the victim's machine, the e-mail sender address is faked to appear as though someone else in the victim's address book sent the message. 

What to Do

  • Always run anti-virus software and be sure it gets updated at least twice per week.
  • If you get a virus in an e-mail attachment and you are sure it is a virus, delete the e-mail message.
  • If you get an attachment from someone you know, consider whether there is enough personal information in the e-mail which a virus program would not know. If you are not sure your acquaintance sent the e-mail call them and be sure before opening the attachment. Do not count on your anti-virus software being able to stop you from getting infected if you open the e-mail attachment. Remember, viruses are not recognized right away by your anti-virus software and you could get a new unrecognized virus before your virus definition updates are released.
  • If you get an e-mail saying a message you sent was undeliverable and you did not send the message, consider whether your system is behaving abnormally. You probably do not have a virus, but if you are not sure, use your anti-virus software to perform a system scan for viruses and remove any viruses found using the procedure in the section about "Removing Viruses", then delete the e-mail.
  • If you get an e-mail saying a message you sent contained a virus, consider whether your system is behaving abnormally. You probably do not have a virus, but if you are not sure, use your anti-virus software to perform a system scan for viruses and remove any viruses found using the procedure in the section about "Removing Viruses", then delete the e-mail.

Example

Below is shown an e-mail from a virus as an example of how a virus writer will try to fool computer users.
From: staff@yourorganization.org [mailto:staff@yourorganization.org]
Sent: Wednesday, March 03, 2004 4:41 AM
To: usertofool@yourorganization.org
Subject: Important notify about your e-mail account.

Dear user of e-mail server "Yourorganization.org",

Our antivirus software has detected a large  ammount of viruses outgoing
from your email account, you may use our free anti-virus tool to  clean  up
your computer software.

For further  details see the attach.

For security reasons attached file  is password protected. The password is
"22352".

Cheers,
   The Yourorganization.org  team                   http://www.yourorganization.org

Of course there is an attachment. In this case the virus sent a zipped file (.zip) and instructed the user how to open it. It was encrypted in a zipped file so the anti-virus scanner could not detect it!

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The Internet Email System

The Internet Email System
The email system that is currently used on the internet was not designed to curb the abuses presented by viruses and SPAM as they are occurring today. The email system today allows:
  • Anyone can set the "From" field in the email to any value they want. This means that you can send an email message and make it look like the President of the United States sent the message. There are ways to tell that this is not the case, but on the surface it will appear like the President of the United States sent the message. This is called faking the sending address.
  • If an email cannot be delivered, the email standard provides for the sender to receive a notification indicating that the message could not be delivered. Some email servers are also set up to notify the sender when a virus is found in an email they sent.
There are several things that the email system in use today does not provide for:
  • The system does not provide for positive identification of the sender.
  • There is no method to prevent a sender from sending unwanted emails.

Email Problems

Given the above conditions, several problems can occur.
  • If the sending address of the email is faked, any messages indicating the message could not be delivered will go to the person who appears to have sent the email rather than the person who actually sent it. This can cause people to receive non deliverable notifications for emails that they did not send which can be very confusing.
  • If a virus sends an email with a faked sender address, a mail server may detect the virus in the message and send a reply to the faked address notifying someone that they sent an email with a virus in it when in fact they did not. This can cause confusion and waste administrators time since users may call administrators and want their systems checked for viruses when they are not acutally infected with a virus. This is why administrators of mail servers should turn off notifications to addresses that appear to have sent a virus.
  • Someone can fake the sender of an email and send embarrassing or annoying messages and possibly jeopardize the reputation of the party they are sending the email as. They can make it appear as though a reputable party is sending smut on the internet. I do not know if there are any laws against this, but there should be. This would be called fraud along with some possible other charges such as libel and slander. There are ways to tell that the sender did not actually send the email but this could still unjustly hurt someone's reputation.
  • Recipients of virus or SPAM emails are unwilling recipients. These emails tie up their time and computer resources. When someone pays for a connection to the internet, and this connection is used to send them unwanted emails, this is the same as a denial of service attack and is essentially stealing. Everyone who connects to the internet has the right to use their connection haw they want and not how someone else wants. I will talk more about this in the section about SPAM. 
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Securing Your System

Securing Your System
There are several measures which you can take to secure your system. The first and most important is to become informed about how your system works and what the threats are. Reading this guide and acting on the tips contained here is a good start.
  • Personal firewall - If you are not behind a corporate firewall, purchase and install a personal firewall on your computer. This will help protect your system from many vulnerabilities that some worms will try to exploit.
  • Updates - Perform system updates often. You can go to the Windows Update site to download updates for your system. Another way to get updates if your system is running Windows 2000 or Windows XP is to configure your system to download automatic updates. This can be done by opening your control panel (Click on "Start", then select "Settings", and click on "Control Panel". To configure updates double click the "Automatic Updates" icon and choose one of three configurations.
  • Use anti-virus software with regular updates. Be sure to run anti-virus software and download updates at least twice per week. There are many brands of anti-virus software which may be purchased at your local computer, office supply store, or on the internet. I will not be recommending any name brands in this tutorial.
  • Be aware of how viruses spread and don't open attachments unless you are SURE they are legitimate. Call the sender if necessary to be sure they sent the email. Be sure your system settings are set so you can recognize potential virus files that may have multiple extensions such as filename.txt.exe. If the extension ends in .exe, .com, or .bat don't double click on it or run it unless you are SURE it is from a legitimate source.
  • Avoid installing bad applications. As mentioned in the section about application programs, some computer programs may come with spyware or adware. Avoiding these can be important in both securing your system and keeping your system performance from being degraded. Keep in mind that adware programs may download and install other programs from the internet. A personal firewall is one defense against this happening because it will normally notify you when a program accesses the internet.
  • Configure your system so you will see all file extensions as described on the page called "Windows File View Settings".
For more information about the security measures you should take, see the Home Computer Security article on this site.

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Worms and Prevention

Worms and Prevention
Since worms spread by taking advantage of vulnerabilities in operating systems or application programs (remember from earlier discussion, vulnerabilities are software errors that allow some kind of unauthorized access when they are used or exploited). You do not need to do anthing special to get a worm except to connect to the internet or an infected network with a system that has vulnerabilities. There are several good defenses against worms.

What is a Firewall?

A firewall is a device that limits access to your system from the outside. A firewall may be a software program running on your computer or it may be a piece of hardware outside your computer. The firewall screens any attempts to access your system and only allows access that you decide to allow. In this way many vulnerabilities that could be used to gain unauthorized access to your system are eliminated.

Worm Prevention

There are three defenses against worms. They are as follows:
  • A personal firewall should be run on any system that is not behind a corporate firewall. This should be done on any computer that connects to the internet even if the connection it uses is a slow dial up connection.
  • Patching your system with updates to fix the vulnerabilities. Patching is the act of downloading updates to the vulnerable operating system or application and applying the update to the program.
  • Continually running anti-virus software which may detect worms. This is not the best defense against worms however because sometimes the worm can infect the system before the anti-virus software can detect it.
Of the above measures the first two are the most effective against worms. For more information about personal firewalls, why you should use them, and how you can update your system, see the Home Computer Security article on this site. 

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Viruses and Worms

Viruses and Worms
In general terms a virus is a program that runs on a system against the owner's or user's wishes and knowledge. Viruses have one or more methods they use to spread. Most commonly they will attach a file to an e-mail message and attempt to trick victims into running the attachment.

Virus Damage

In most cases, viruses can do any amount of damage the creator intends them to do. They can send your data to a third party and then delete your data from your computer. They can also ruin your system and render it unusable without a re-installation of the operating system. Most have not done this much damage in the past, but could easily do this in the future. Usually the virus will install files on your system then will change your system so the virus is run every time you start your system. It will then attempt to replicate itself by sending itself to other potential victims.
The normal effect a virus will have on your system is that over time your system will run slower. Also when you are using the internet your connection may seem to run slower. Eventually you may have trouble running programs on your system, your system may freeze, and in the worst case you may not be able to get it to boot up when you turn your computer on.

How Viruses or Worms Spread

Most commonly viruses today use e-mail to spread however they have used one or more of the following methods to spread in the past.

  • Some viruses will load themselves onto any part of a writable removable drive as possible and spread from computer to computer as people use the removable drive.
  • A worm is a program similar to a virus that will exploit a vulnerability in an operating system or application that a computer user is running. The best defense against a worm is to have either a personal firewall on your system or be behind a corporate firewall. Another good defense is to update your system regularly. All you need to do to get a worm is to connect an unpatched computer to the internet or infected network when your computer does not have firewall protection.
  • Most viruses will spread themselves using e-mail attachments. They may tell the user that they neet to open the attachment to get the rest of the information that is being sent to them. Many times the virus may claim it is an administrator and the user needs to either read the data or install a program on their system. Viruses have even claimed to be Microsoft sending a system patch as an attachment to the e-mail. Microsoft would never send a system patch through e-mail.
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File Backups

File Backups
File backups are very important to protect your data. Is your hard drive fails or your operating system malfunctions, you could loose all your data. If you do regular backups, you will drastically reduce the data loss that could occur.

Using the Network for Backups

Backing up your data is very important. If you are operating on a corporate or organizational network and have disk drives shared from a file server it is likely that files stored there are backed up every night. If possible you should store your files on this server.
Since Windows operating systems use the "My Documents" folder as the location to store your files by default it will be helpful to set up your system so the "My Documents" folder points to one of your network drives. If running a Windows 2000 or Windows XP system, you can right click on the "My Documents" folder ether on your desktop or displayed from the Start menu and select properties. A dialog box similar to the one shown below will appear.
My Documents Properties 
 
Click on the "Move" button. A dialog box similar to the one below will appear.
Browse For 
Expand the "My Computer" object by clicking on the + next to it. Then select the appropriate network drive that is best to put your documents in.  
 

How to Backup Data if You do not have a network

If you do not have a network and only have a single computer you should periodically back up your data. You should purchase or own one of the following:
  • A read/write CD ROM or DVD drive
  • A Zip drive
  • A tape drive - Usually these are more expensive.
You should be aware of where you store your files and you should also know where your mail files are stored by your mail program such as Outlook or Outlook Express. If you right click on your inbox folder in Outlook Express you can find the location where your mail is stored. On my system it is stored in the folder at: C:\Documents and Settings\Username\Local Settings\Application Data\Identities\{B718C535-6548-4E1D-A5D2-7D1B41CFEB2E}\Microsoft\Outlook Express\ where username is the name I login with. If you are using Outlook, it is normally stored in a file of type .pst and on my system it is in the folder C:\Documents and Settings\Username\Local Settings\Application Data\Microsoft\Outlook\ where Username is the name I login with.

Setting up a Backup Job

To open the Windows backup program on Windows 2000, select Start, then Programs, then Accessories, then System Tools, then Backup. You must be a backup operator or administrator on your system to create a backup job. The backup utility will start as shown below.
Backup 
 

Immediate Backup

If you want to do an immediate backup, click on the Backup tab and select the files that you want to backup. On my system I selected the folders C:\Documents and Settings\Username\Local Settings\Application Data\Identities\, C:\Documents and Settings\Username\Local Settings\Application Data\Microsoft\Outlook\, and other areas where I store my data such as "My Computer". Also be sure to check the box next to "System State" which may save you a lot of grief if you have trouble with your system.
Backup
Click on the "Start backup" button and on the dialog box that appears select either "Append..." or "Replace..." data on the media, then select "Start Backup".

Schedule a Backup

To schedule a backup, click on the "Schedule Backups" tab. The Backup program will show a calendar as shown below.
Backup Calendar
Click the "Add Job" button. A backup wizard will start. Click "Next". A "What to backup" dialog box as shown below will appear.
What to Backup
Select "Backup selected files, drives, or network data" and click "Next". On the next box select the items you want to backup by first clicking the + next to "My Computer" to expand it as shown below.
Items to back up
Select the items in the same way as discussed under the header called "Immediate Backup" above and click Next. The dialog box will change and allow you to select the name and location of the file the backup will be stored in. Click "Next" and a dialog box will ask the type of backup you want to perform. A normal backup will be sufficient so select it unless you have another preference and click "Next". You can read more about the backup types at the Windows NT File Backup Page.
After clicking next, select "Verify data after backup" and click "Next". Select whether to Append or replace data if the file already exixst at the specified location and click "Next". Accept or specify the backup label and click "Next". The below dialog box will appear.
Time to back up
Click on the "Set Schedule button and the dialog box below will appear.
Time to back up
Select your preferred backup times and how often you want to do this backup such as weekly. Click OK and the backup schedule dialog box will disappear. Enter the name of your backup job and click next on the "When to back up" dialog box. Click "Finish" to complete the process. Backups should run when you have scheduled them.
If you want to delete a backup job that you have scheduled, click on the "Schedule Jobs" tab and click on the job shown on the calendar. A dialog box with the job name will pop up. You can click on the "Delete" button next to the Job name to delete the Job.

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View Settings

View Settings

The Default Windows Setting is Dangerous

Windows systems come with default file view settings. The default is to "Hide file extensions for known file types". This setting can be used to decieve a computer user into believing that a file is safe to open when it is not. Files containing viruses can be sent to a computer with the name "document.txt.exe" which is a file that the computer will run. The file will appear to the computer user as "document.txt" making the user believe that it is safe to open, but if the user clicks on it the file will be run and be able to infect the computer.

Changing the View Settings

This section will tell you hw to change your settings so you will always see file extensions. It will also tell you how to beable to see file details.
Open "My Computer" by clicking on the "My Computer" icon on your desktop. Click on the menu item "View" and select "Details" from the drop down menu. This will change the current settings for the folder or location you are in, but the change is not permanent yet.
To change the file view settings, if you are using Windows 2000 or XP click on the menu item "Tools" and "Folder options" selection. If you are using Windows 98, click on "View", and "Folder options". A dialog box similar to the one below should appear.
Folder Options
Click on the view tab and the dialog box will change as shown below:
Folder Options View tab
Click on the button in the Folder Views area that says "Like current folder" and answer yes when asked if you want to change all folders to match the current folder. Change the rest of the settings to match the dialog box as shown below:
Folder Options View tab
The first three selections are display settings which make it more convenient to navigate through files and folders. Be sure and uncheck the checkbox next to "Hide file extensions for known file types". If you are using Windows 2000 or Windows XP, this should be done for every user that logs in since each unique user that uses the machine will get their own desktop and user profile. 

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File Management

File Management

File Organization

Files can be placed in folders similar to the way single sheets of paper can be placed into folders in a file cabinet. Folders can be created on the hard drive or nested inside each other any way the computer user desires.

Browsing Your files using Windows

If using a Windows operating system double click on the "My Computer" icon on your desktop. A window like the one shown below will open. 



My Computer


The first drive in the window shown is a floppy drive. It is labeled as drive A. The second disk is the system hard drive labeled as drive C. The third disk shown is a data disk shown as drive D. This is not a normal setup on most systems but I like to use a hard drive to hold my data that is different than the hard drive that holds the operating system. Drives E and F are compact disks (CD ROM drives) of which one is a read/write drive.
The drive letters will vary depending on how your system is configured and depending on whether you have any network drives. If you do have network drives, you should use them for the mail place you store your files. This is because files on network drives are usually backed up nightly in most organizations. If your files are not backed up and your hard drive fails, you will lose your data.

Local disk 

Copying Files

There are several ways Windows operating systems allow files to be copied or moved. They include:
  • Drag and drop - In the window above it is easy to drag one of the files into one of the folders. This will move the file into the folder. This can also be done by opening two windows using the "My Computer" icon and dragging the file from one window to another.
  • Copy and paste - You can open a "My Computer" window, and do the following:
    • On the "My Computer" menu select "Edit", then "Copy".
    • Navigate to the location where you want to put the file. You can navigate by using the "Up" folder to go up one level into the folder structure or by double clicking on folders to enter them. If the "Up" folder does not exist in your "My Computer" window, on your menu, select "View", then "toolbars", then select "Standard Buttons".
    • On the "My Computer" menu select "Edit", then "Paste". The file will be copied to the location you have navigated to.

Copying Multiple Files

There are several tricks that can be used to make copying or moving multiple files easier. They involve the selection of the files to be copied or moved. You can hold down the Shift key and select one file by clicking on it with the left mouse button (called left clicking). While still holding the Shift key down left click on another file several files down on the list. This will cause all files from the first one through the last one selected to be highlighted and selected. Release the Shift key. After this, you can hold down the Ctrl key and by left clicking on any other files, they can be either selected or de-selected. Release the Ctrl key. Once you have selected the files you can move them by dragging and dropping them (after releasing both the shift and control keys) into another folder. This is done as follows:
  1. Put the mouse cursor over one of the selected files.
  2. Left clicking the mouse and hold it down
  3. Drag the file to the desired location such as a folder icon.
  4. Release the left mouse button.
If you want to copy the files:
  1. On the "My Computer" menu select "Edit", then "Copy".
  2. Navigate to the location where you want to put the file.
  3. On the "My Computer" menu select "Edit", then "Paste". The file will be copied to the location you have navigated to. 
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