CCNA VLan Basic knowledge
Some basic knowledge of LANs, different topologies, and working of Local Area Networks is required to proceed further.
What is a VLAN?
To refresh your memory, a Local Area Network (LAN) is a set of connected devices like computers, hubs, and switches sharing the same pool of logical address space. Normally, a router is required to route packets from one LAN to another LAN. Traditionally, all packets within a LAN are broadcast to all other devices connected to that particular LAN.
As a result, a traditional LAN has several disadvantages as below:
* Usable bandwidth is shared among all the devices connected to the LAN
* ALL devices connected within a LAN can hear ALL the packets irrespective of whether the packet is meant for that device or not. It is possible for some unscrupulous node listening to data packets not meant for that.
* Suppose, your organization has different departments. Using a traditional LAN, when any changes take place within the organization, physical cables and devices need to be moved to reorganize the LAN infrastructure.
* A LAN cannot extend beyond its physical boundary across a WAN as in VLANs.
If you are looking for a simple networked solution for a small office, it may be a good idea to have a traditional LAN setup with a few hubs or switches. However, if you are planning for a large building or campus wide LAN for several individual departments, a VLAN is almost essential.
Virtual LANs (VLANs) can be considered as an intelligent LAN consisting of different physical LAN segments enabling them to communicate with each other as if they were all on the same physical LAN segment.
Benefits of VLAN: Several of the disadvantages of traditional LANs can be eliminated with the implementation of VLANs.
1. Improved Performance: In a traditional LAN, all the hosts within the LAN receive broadcasts, and contend for available bandwidth. As a result, the bandwidth is shared among all the connected devices within the LAN segment. If you are running high-bandwidth consumption applications such as groupware or server forms, a threshold point may easily be reached. After a threshold, the users may find the LAN too slow or un-responsive. With the use of VLAN, you can divide the big LAN into several smaller VLANs. For example, if there are two file servers, each operating at 100Mbps, in a traditional LAN both the servers have to share the LAN bandwidth of 100Mbps. If you put both the servers in separate VLANs, then both have an available bandwidth of 100Mbps each. Here the available bandwidth has been doubled.
2. Functional separation of an institute or a company: It is often required to separate the functional groups within a company or institute. For example, it might be necessary to separate HR department LAN from that of Production LAN. Traditionally, it requires a router to separate two physical LANs. However, you can set up two VLANs, one for Finance, and the other for Production without a router. A switch can route frames from one VLAN to another VLAN. With VLAN's it is easier to place a workgroup together eventhough they are physically in different buildings. In this case Finance VLAN does not forward packets to Production VLAN, providing additional security.
3. Ease of Network Maintenance:
Network maintenance include addition, removal, and changing the network users. With traditional LANs, when ever a User moves, it may be necessary to re-configure the user work station, router, and the servers. Some times, it may also be necessary to lay the cable, or reconfigure hubs and switches. If you are using VLANs, many of these reconfiguration tasks become unnecessary. For example, you can avoid network address configuration on the work station and the corresponding router if you use VLAN. This is because, routing traffic within VLANs doesn't require a router.
However, VLAN's add some administrative complexity, since the administration needs to manage virtual workgroups using VLANs.
4. Reduced Cost
VLANs minimize the network administration by way of reduced maintenance on account of workstation addition/deletion/changes. This in turn reduce the costs associated with LAN maintenance.
5. Security
Using a LAN, all work stations within the LAN get the frames meant for all other work stations within the broadcast domain. Since a VLAN splits the broadcast domain into two or more, it is possible to put work stations sharing sensitive data in one VLAN, and other work station in another VLAN. Of course, if two VLANs are not sufficient, you can split the work stations into as many VLANs as required. VLAN's can also be used to set up firewalls, restrict access, and send any intrusion alerts to the administrator.
Thursday, November 19, 2009
Router Boot-up Process
Router Boot-up Process
Router Boot-up Process
There are four major phases to the bootup process:
1. Performing the POST
2. Loading the bootstrap program
3. Locating and loading the Cisco IOS software
4. Locating and loading the startup configuration file or entering setup mode
1. Performing the POST
The Power-On Self Test (POST) is a common process that occurs on almost every computer during bootup. The POST process is used to test the router hardware. When the router is powered on, software on the ROM chip conducts the POST. During this self-test, the router executes diagnostics from ROM on several hardware components including the CPU, RAM, and NVRAM. After the POST has been completed, the router executes the bootstrap program.
2. Loading the Bootstrap Program
After the POST, the bootstrap program is copied from ROM into RAM. Once in RAM, the CPU executes the instructions in the bootstrap program. The main task of the bootstrap program is to locate the Cisco IOS and load it into RAM.
Note: At this point, if you have a console connection to the router, you will begin to see output on the screen.
3. Locating and Loading Cisco IOS
Locating the Cisco IOS software. The IOS is typically stored in flash memory, but can also be stored in other places such as a TFTP (Trivial File Transfer Protocol) server.
If a full IOS image can not be located, a scaled-down version of the IOS is copied from ROM into RAM. This version of IOS is used to help diagnose any problems and can be used to load a complete version of the IOS into RAM.
Note: A TFTP server is usually used as a backup server for IOS but it can also be used as a central point for storing and loading the IOS. IOS management and using the TFTP server is discussed in a later course.
4. Locating and Loading the Configuration File
Locating the Startup Configuration File. After the IOS is loaded, the bootstrap program searches for the startup configuration file, known as startup-config, in NVRAM. This file has the previously saved configuration commands and parameters including:
interface addresses
routing information
passwords
any other configurations saved by the network administrator
If the startup configuration file, startup-config, is located in NVRAM, it is copied into RAM as the running configuration file, running-config.
Executing the Configuration File. If a startup configuration file is found in NVRAM, the IOS loads it into RAM as the running-config and executes the commands in the file, one line at a time. The running-config file contains interface addresses, starts routing processes, configures router passwords and defines other characteristics of the router.
Enter Setup Mode (Optional). If the startup configuration file can not be located, the router prompts the user to enter setup mode. Setup mode is a series of questions prompting the user for basic configuration information. Setup mode is not intended to be used to enter complex router configurations, and it is not commonly used by network administrators.
When booting a router that does not contain a startup configuration file, you will see the following question after the IOS has been loaded:
Command Line Interface
Depending on the platform and IOS, the router may ask the following question before displaying the prompt:
Would you like to terminate autoinstall? [yes]:
Press the Enter key to accept the default answer.
Router>
Note: If a startup configuration file was found, the running-config may contain a hostname and the prompt will display the hostname of the router.
Once the prompt displays, the router is now running the IOS with the current running configuration file. The network administrator can now begin using IOS commands on this router.
Note: The bootup process is discussed in more detail in a later course.
Router Boot-up Process
There are four major phases to the bootup process:
1. Performing the POST
2. Loading the bootstrap program
3. Locating and loading the Cisco IOS software
4. Locating and loading the startup configuration file or entering setup mode
1. Performing the POST
The Power-On Self Test (POST) is a common process that occurs on almost every computer during bootup. The POST process is used to test the router hardware. When the router is powered on, software on the ROM chip conducts the POST. During this self-test, the router executes diagnostics from ROM on several hardware components including the CPU, RAM, and NVRAM. After the POST has been completed, the router executes the bootstrap program.
2. Loading the Bootstrap Program
After the POST, the bootstrap program is copied from ROM into RAM. Once in RAM, the CPU executes the instructions in the bootstrap program. The main task of the bootstrap program is to locate the Cisco IOS and load it into RAM.
Note: At this point, if you have a console connection to the router, you will begin to see output on the screen.
3. Locating and Loading Cisco IOS
Locating the Cisco IOS software. The IOS is typically stored in flash memory, but can also be stored in other places such as a TFTP (Trivial File Transfer Protocol) server.
If a full IOS image can not be located, a scaled-down version of the IOS is copied from ROM into RAM. This version of IOS is used to help diagnose any problems and can be used to load a complete version of the IOS into RAM.
Note: A TFTP server is usually used as a backup server for IOS but it can also be used as a central point for storing and loading the IOS. IOS management and using the TFTP server is discussed in a later course.
4. Locating and Loading the Configuration File
Locating the Startup Configuration File. After the IOS is loaded, the bootstrap program searches for the startup configuration file, known as startup-config, in NVRAM. This file has the previously saved configuration commands and parameters including:
interface addresses
routing information
passwords
any other configurations saved by the network administrator
If the startup configuration file, startup-config, is located in NVRAM, it is copied into RAM as the running configuration file, running-config.
Executing the Configuration File. If a startup configuration file is found in NVRAM, the IOS loads it into RAM as the running-config and executes the commands in the file, one line at a time. The running-config file contains interface addresses, starts routing processes, configures router passwords and defines other characteristics of the router.
Enter Setup Mode (Optional). If the startup configuration file can not be located, the router prompts the user to enter setup mode. Setup mode is a series of questions prompting the user for basic configuration information. Setup mode is not intended to be used to enter complex router configurations, and it is not commonly used by network administrators.
When booting a router that does not contain a startup configuration file, you will see the following question after the IOS has been loaded:
Command Line Interface
Depending on the platform and IOS, the router may ask the following question before displaying the prompt:
Would you like to terminate autoinstall? [yes]:
Press the Enter key to accept the default answer.
Router>
Note: If a startup configuration file was found, the running-config may contain a hostname and the prompt will display the hostname of the router.
Once the prompt displays, the router is now running the IOS with the current running configuration file. The network administrator can now begin using IOS commands on this router.
Note: The bootup process is discussed in more detail in a later course.
Saturday, October 31, 2009
Windows ARP Spoofer 0.5.3
Windows ARP Spoofer 0.5.3
Download Windows ARP Spoofer 0.5.3 at High Speed
Windows ARP Spoofer 0.5.3 (Size: 7,5 MB)
Windows ARP Spoofer (WinArpSpoof) is a program that can scan the computers including network devices and can spoof their ARP tables on local area network and can act as a router while pulling all packets on LAN.
Download Link
http://depositfiles.com/en/files/h0agra61d/
Monday, October 26, 2009
The Elements of a NetworksV
The Elements of a NetworksV
We close this section with an example to tie together how the elements of networks - devices, media, and services - are connected by rules to deliver a message. People often only picture networks in the abstract sense. We create and send a text message and it almost immediately shows up on the destination device. Although we know that between our sending device and the receiving device there is a network over which our message travels, we rarely think about all the parts and pieces that make up that infrastructure.
The Messages
In the first step of its journey from the computer to its destination, our instant message gets converted into a format that can be transmitted on the network. All types of messages must be converted to bits, binary coded digital signals, before being sent to their destinations. This is true no matter what the original message format was: text, video, voice, or computer data. Once our instant message is converted to bits, it is ready to be sent onto the network for delivery.
The Devices
To begin to understand the robustness and complexity of the interconnected networks that make up the Internet, it is necessary to start with the basics. Take the example of sending the text message using an instant messaging program on a computer. When we think of using network services, we usually think of using a computer to access them. But, a computer is only one type of device that can send and receive messages over a network. Many other types of devices can also be connected to the network to participate in network services. Among these devices are telephones, cameras, music systems, printers and game consoles.
In addition to the computer, there are numerous other components that make it possible for our instant message to be directed across the miles of wires, underground cables, airwaves and satellite stations that might exist between the source and destination devices. One of the critical components in any size network is the router. A router joins two or more networks, like a home network and the Internet, and passes information from one network to another. Routers in a network work to ensure that the message gets to its destination in the most efficient and quickest manner.
The Medium
To send our instant message to its destination, the computer must be connected to a wired or wireless local network. Local networks can be installed in homes or businesses, where they enable computers and other devices to share information with each other and to use a common connection to the Internet.
Wireless networks allow the use of networked devices anywhere in an office or home, even outdoors. Outside the office or home, wireless networking is available in public hotspots, such as coffee shops, businesses, hotel rooms, and airports.
Many installed networks use wires to provide connectivity. Ethernet is the most common wired networking technology found today. The wires, called cables, connect the computers and other devices that make up the networks. Wired networks are best for moving large amounts of data at high speeds, such as are required to support professional-quality multimedia.
The Services
Network services are computer programs that support the human network. Distributed on devices throughout the network, these services facilitate online communication tools such as e-mail, bulletin/discussion boards, chat rooms, and instant messaging. In the case of instant messaging, for example, an instant messaging service, provided by devices in the cloud, must be accessible to both the sender and recipient.
The Rules
Important aspects of networks that are neither devices nor media are rules, or protocols. These rules are the standards and protocols that specify how the messages are sent, how they are directed through the network, and how they are interpreted at the destination devices. For example, in the case of Jabber instant messaging, the XMPP, TCP, and IP protocols are all important sets of rules that enable our communication to occur.
The Elements of a Networks4
The Elements of a Networks4Human beings often seek to send and receive a variety of message using computer applications; these applications require services be provided by the network. Some of these services include the World Wide Web, e-mail, instant messaging, and IP Telephony. Devices interconnected by medium to provide services must be governed by rules, or protocols. In the chart, some common services and a protocol most directly associated with that service are listed.
Protocols are the rules that the networked devices use to communicate with each other. The industry standard in networking today is a set of protocols called TCP/IP (Transmission Control Protocol/Internet Protocol). TCP/IP is used in home and business networks, as well as being the primary protocol of the Internet. It is TCP/IP protocols that specify the formatting, addressing and routing mechanisms that ensure our messages are delivered to the correct recipient.
The Elements of a Networks3
The Elements of a Networks3
For a network to function, the devices must be interconnected. Network connections can be wired or wireless. In wired connections, the medium is either copper, which carries electrical signals, or optical fiber, which carries light signals. In wireless connections, the medium is the Earth's atmosphere, or space, and the signals are microwaves. Copper medium includes cables, such as twisted pair telephone wire, coaxial cable, or most commonly, what is known as Category 5 Unshielded Twisted Pair (UTP) cable. Optical fibers, thin strands of glass or plastic that carry light signals, are another form of networking media. Wireless media may include the home wireless connection between a wireless router and a computer with a wireless network card, the terrestrial wireless connection between two ground stations, or the communication between devices on earth and satellites. In a typical journey across the Internet, a message may travel across a variety of media.
The Elements of a Networks2
The Elements of a Networks 2In this course, many networking devices will be discussed. Networking is a very graphically oriented subject, and icons are commonly used to represent networking devices. On the left side of the diagram are shown some common devices which often originate messages that comprise our communication. These include various types of computers (a PC and laptop icon are shown), servers, and IP phones. On local area networks these devices are typically connected by LAN media (wired or wireless).
The right side of the figure shows some of the most common intermediate devices, used to direct and manage messages across the network, as well as other common networking symbols. Generic symbols are shown for:
Switch - the most common device for interconnecting local area networks
Firewall -provides security to networks
Router - helps direct messages as they travel across a network
Wireless Router - a specific type of router often found in home networks
Cloud - used to summarize a group of networking devices, the details of which may be unimportant to the discussion at hand
Serial Link - one form of WAN interconnection, represented by the lightning bolt-shaped line
The Elements of a Networks1
The Elements of a Networks 1The diagram shows elements of a typical network, including devices, media, and services, tied together by rules, that work together to send messages. We use the word messages as a term that encompasses web pages, e-mail, instant messages, telephone calls, and other forms of communication enabled by the Internet. In this course, we will learn about a variety of messages, devices, media, and services that allow the communication of those messages. We will also learn about the rules, or protocols, that tie these network elements together.
Sunday, October 25, 2009
Communication Over Networks
Communication Over Networks
Being able to reliably communicate to anyone, anywhere, is becoming increasingly important to our personal and business lives. In order to support the immediate delivery of the millions of messages being exchanged between people all over the world, we rely on a web of interconnected networks. These data or information networks vary in size and capabilities, but all networks have four basic elements in common:
Rules or agreements to govern how the messages are sent, directed, received and interpreted.
The messages or units of information that travel from one device to another
A means of interconnecting these devices - a medium that can transport the messages from one device to another
Devices on the network that exchange messages with each other
The standardization of the various elements of the network enables equipment and devices created by different companies to work together. Experts in various technologies can contribute their best ideas on how to develop an efficient network, without regard to the brand or manufacturer of the equipment.
Friday, October 23, 2009
1.2.2 Quality of Communication 2
Internal Factors
Internal factors that interfere with network communication are related to the nature of the message itself.
Different types of messages may vary in complexity and importance. Clear and concise messages are usually easier to understand than complex messages. Important communications require more care to ensure that they are delivered and understood by the recipient.
Internal factors affecting the successful communication across the network include:
The size of the message
The complexity of the message
The importance of the message
Large messages may be interrupted or delayed at different points within the network. A message with a low importance or priority could be dropped if the network becomes overloaded.
Both the internal and external factors that affect the receipt of a message must be anticipated and controlled for network communications to be successful. New innovations in network hardware and software are being implemented to ensure the quality and reliability of network communications.
Internal factors that interfere with network communication are related to the nature of the message itself.
Different types of messages may vary in complexity and importance. Clear and concise messages are usually easier to understand than complex messages. Important communications require more care to ensure that they are delivered and understood by the recipient.
Internal factors affecting the successful communication across the network include:
The size of the message
The complexity of the message
The importance of the message
Large messages may be interrupted or delayed at different points within the network. A message with a low importance or priority could be dropped if the network becomes overloaded.
Both the internal and external factors that affect the receipt of a message must be anticipated and controlled for network communications to be successful. New innovations in network hardware and software are being implemented to ensure the quality and reliability of network communications.
1.2.2 Quality of Communication
Communication between individuals is determined to be successful when the meaning of the message understood by the recipient matches the meaning intended by the sender.
For data networks, we use the same basic criteria to judge success. However, as a message moves through the network, many factors can prevent the message from reaching the recipient or distort its intended meaning. These factors can be either external or internal.
External Factors
The external factors affecting communication are related to the complexity of the network and the number of devices a message must pass through on its route to its final destination.
External factors affecting the success of communication include:
The quality of the pathway between the sender and the recipient
The number of times the message has to change form
The number of times the message has to be redirected or readressed
The number of other messages being transmitted simultaneously on the communication network
The amount of time allotted for successful communication
For data networks, we use the same basic criteria to judge success. However, as a message moves through the network, many factors can prevent the message from reaching the recipient or distort its intended meaning. These factors can be either external or internal.
External Factors
The external factors affecting communication are related to the complexity of the network and the number of devices a message must pass through on its route to its final destination.
External factors affecting the success of communication include:
The quality of the pathway between the sender and the recipient
The number of times the message has to change form
The number of times the message has to be redirected or readressed
The number of other messages being transmitted simultaneously on the communication network
The amount of time allotted for successful communication
What is Communication?
The widespread adoption of the Internet by the entertainment and travel industries enhances the ability to enjoy and share many forms of recreation, regardless of location. It is possible to explore places interactively that previously we could only dream of visiting, as well as preview the actual destinations before making a trip. The details and photographs from these adventures may be posted online for others to view.
The Internet is used for traditional forms of entertainment, as well. We listen to recording artists, preview or view motion pictures, read entire books and download material for future offline access. Live sporting events and concerts can be experienced as they are happening, or recorded and viewed on demand.
Networks enable the creation of new forms of entertainment, such as online games. Players participate in any kind of online competition that that game designers can imagine. We compete with friends and foes around the world in the same manner if they were in the same room.
Even offline activities are enhanced using network collaboration services. Global communities of interest have grown rapidly. We share common experiences and hobbies well beyond our local neighborhood, city, or region. Sports fans share opinions and facts about their favorite teams. Collectors display prized collections and get expert feedback about them.
Online markets and auction sites provide the opportunity to buy, sell and trade all types of merchandise.
Whatever form of recreation we enjoy in the human network, networks are improving our experience.
The Internet is used for traditional forms of entertainment, as well. We listen to recording artists, preview or view motion pictures, read entire books and download material for future offline access. Live sporting events and concerts can be experienced as they are happening, or recorded and viewed on demand.
Networks enable the creation of new forms of entertainment, such as online games. Players participate in any kind of online competition that that game designers can imagine. We compete with friends and foes around the world in the same manner if they were in the same room.
Even offline activities are enhanced using network collaboration services. Global communities of interest have grown rapidly. We share common experiences and hobbies well beyond our local neighborhood, city, or region. Sports fans share opinions and facts about their favorite teams. Collectors display prized collections and get expert feedback about them.
Online markets and auction sites provide the opportunity to buy, sell and trade all types of merchandise.
Whatever form of recreation we enjoy in the human network, networks are improving our experience.
Networks Supporting the Way We Play
The widespread adoption of the Internet by the entertainment and travel industries enhances the ability to enjoy and share many forms of recreation, regardless of location. It is possible to explore places interactively that previously we could only dream of visiting, as well as preview the actual destinations before making a trip. The details and photographs from these adventures may be posted online for others to view.
The Internet is used for traditional forms of entertainment, as well. We listen to recording artists, preview or view motion pictures, read entire books and download material for future offline access. Live sporting events and concerts can be experienced as they are happening, or recorded and viewed on demand.
Networks enable the creation of new forms of entertainment, such as online games. Players participate in any kind of online competition that that game designers can imagine. We compete with friends and foes around the world in the same manner if they were in the same room.
Even offline activities are enhanced using network collaboration services. Global communities of interest have grown rapidly. We share common experiences and hobbies well beyond our local neighborhood, city, or region. Sports fans share opinions and facts about their favorite teams. Collectors display prized collections and get expert feedback about them.
Online markets and auction sites provide the opportunity to buy, sell and trade all types of merchandise.
Whatever form of recreation we enjoy in the human network, networks are improving our experience.
The Internet is used for traditional forms of entertainment, as well. We listen to recording artists, preview or view motion pictures, read entire books and download material for future offline access. Live sporting events and concerts can be experienced as they are happening, or recorded and viewed on demand.
Networks enable the creation of new forms of entertainment, such as online games. Players participate in any kind of online competition that that game designers can imagine. We compete with friends and foes around the world in the same manner if they were in the same room.
Even offline activities are enhanced using network collaboration services. Global communities of interest have grown rapidly. We share common experiences and hobbies well beyond our local neighborhood, city, or region. Sports fans share opinions and facts about their favorite teams. Collectors display prized collections and get expert feedback about them.
Online markets and auction sites provide the opportunity to buy, sell and trade all types of merchandise.
Whatever form of recreation we enjoy in the human network, networks are improving our experience.
Networks Supporting the Way We Work
Initially, data networks were used by businesses to internally record and manage financial information, customer information, and employee payroll systems. These business networks evolved to enable the transmission of many different types of information services, including e-mail, video, messaging, and telephony.
Intranets, private networks in use by just one company, enable businesses to communicate and perform transactions among global employee and branch locations. Companies develop extranets, or extended internetworks, to provide suppliers, vendors, and customers limited access to corporate data to check order status, inventory, and parts lists.
Today, networks provide a greater integration between related functions and organizations than was possible in the past.
Consider these business scenarios.
A wheat farmer in Australia uses a laptop enabled with a Global Positioning System (GPS) to plant a crop with precision and efficiency. At harvest time, the farmer can co-ordinate harvesting with the availability of grain transporters and storage facilities. Using mobile wireless technology, the grain transporter can monitor the vehicle in-route in order to maintain the best fuel efficiency and safe operation. Changes in status can be relayed to the driver of the vehicle instantly.
Remote workers, called teleworkers or telecommuters, use secure remote access services from home or while traveling. The data network enables them to work as if they were on-site, with access to all the network-based tools normally available for their jobs. Virtual meetings and conferences can be convened which include people in remote locations. The network provides audio and video capability so all participants can both see and hear each other. The information from the meetings can be recorded to a wiki or blog. The latest versions of the agenda and minutes can be shared as soon as they are created.
There are many success stories illustrating innovative ways networks are being used to make us more successful in the workplace. Some of these scenarios are available through the Cisco web site at http://www.cisco.com
Intranets, private networks in use by just one company, enable businesses to communicate and perform transactions among global employee and branch locations. Companies develop extranets, or extended internetworks, to provide suppliers, vendors, and customers limited access to corporate data to check order status, inventory, and parts lists.
Today, networks provide a greater integration between related functions and organizations than was possible in the past.
Consider these business scenarios.
A wheat farmer in Australia uses a laptop enabled with a Global Positioning System (GPS) to plant a crop with precision and efficiency. At harvest time, the farmer can co-ordinate harvesting with the availability of grain transporters and storage facilities. Using mobile wireless technology, the grain transporter can monitor the vehicle in-route in order to maintain the best fuel efficiency and safe operation. Changes in status can be relayed to the driver of the vehicle instantly.
Remote workers, called teleworkers or telecommuters, use secure remote access services from home or while traveling. The data network enables them to work as if they were on-site, with access to all the network-based tools normally available for their jobs. Virtual meetings and conferences can be convened which include people in remote locations. The network provides audio and video capability so all participants can both see and hear each other. The information from the meetings can be recorded to a wiki or blog. The latest versions of the agenda and minutes can be shared as soon as they are created.
There are many success stories illustrating innovative ways networks are being used to make us more successful in the workplace. Some of these scenarios are available through the Cisco web site at http://www.cisco.com
Networks Supporting the Way We Learn3
In the business world, the use of networks to provide efficient and cost-effective employee training is increasing in acceptance. Online learning opportunities can decrease time-consuming and costly travel yet still ensure that all employees are adequately trained to perform their jobs in a safe and productive manner.
Online courseware and delivery offer many benefits to businesses. Among the benefits are:
Current and accurate training materials. Collaboration between vendors, equipment manufacturers and training providers ensures that the courseware is up-to-date with the latest processes and procedures. When errors in materials are found and corrected, the new courseware is immediately available to all employees.
Availability of training to a wide audience. Online training is not dependent on travel schedules, instructor availability or physical class size. Employees can be given deadlines by which training is to be completed and the employees can access the courseware when it is convenient.
Consistent quality of instruction. The quality of the instruction does not vary as it would if different instructors were delivering an in-person course. The online curriculum provides a consistent core of instruction to which instructors can add additional expertise.
Cost reduction. In addition to reducing the cost of travel and the lost time associated with travel, there are other cost reducing factors for business related to online training. It is usually less expensive to revise and update online courseware than it is to update paper-based material. Facilities to support in-person training can also be reduced or eliminated.
Many businesses also provide customer training online. This courseware enables the customers to use the products and services provided by the business in the best manner, reducing calls to the help lines or customer service centers.
Online courseware and delivery offer many benefits to businesses. Among the benefits are:
Current and accurate training materials. Collaboration between vendors, equipment manufacturers and training providers ensures that the courseware is up-to-date with the latest processes and procedures. When errors in materials are found and corrected, the new courseware is immediately available to all employees.
Availability of training to a wide audience. Online training is not dependent on travel schedules, instructor availability or physical class size. Employees can be given deadlines by which training is to be completed and the employees can access the courseware when it is convenient.
Consistent quality of instruction. The quality of the instruction does not vary as it would if different instructors were delivering an in-person course. The online curriculum provides a consistent core of instruction to which instructors can add additional expertise.
Cost reduction. In addition to reducing the cost of travel and the lost time associated with travel, there are other cost reducing factors for business related to online training. It is usually less expensive to revise and update online courseware than it is to update paper-based material. Facilities to support in-person training can also be reduced or eliminated.
Many businesses also provide customer training online. This courseware enables the customers to use the products and services provided by the business in the best manner, reducing calls to the help lines or customer service centers.
Networks Supporting the Way We Learn2
The Cisco Networking Academy Program, which offers this course, is an example of a global online learning experience. The instructor provides a syllabus and establishes a preliminary schedule for completing the course content. The Academy program supplements the expertise of the instructor with an interactive curriculum that provides many forms of learning experiences. The program provides text, graphics, animations, and a simulated networking environment tool called Packet Tracer. Packet Tracer provides a way to build virtual representations of networks and emulate many of the functions of networking devices.
Students may communicate with the instructor and fellow students using online tools, like e-mail, bulletin/discussion boards, chat rooms, and instant messaging. Links provide access to learning resources outside of the courseware. Blended e-learning provides the benefits of computer-based training while retaining advantages of instructor-led curriculum. Students have the opportunity to work online at their own pace and skill level while still having access to an instructor and other live resources.
In addition to the benefits for the student, networks have improved the management and administration of courses as well. Some of these online functions include enrollment, assessment delivery and grade books.
Students may communicate with the instructor and fellow students using online tools, like e-mail, bulletin/discussion boards, chat rooms, and instant messaging. Links provide access to learning resources outside of the courseware. Blended e-learning provides the benefits of computer-based training while retaining advantages of instructor-led curriculum. Students have the opportunity to work online at their own pace and skill level while still having access to an instructor and other live resources.
In addition to the benefits for the student, networks have improved the management and administration of courses as well. Some of these online functions include enrollment, assessment delivery and grade books.
Networks Supporting the Way We Learn
Communication, collaboration, and engagement are fundamental building blocks of education. Institutions are continually striving to enhance these processes to maximize the dissemination of knowledge. Robust and reliable networks support and enrich student learning experiences. These networks deliver learning material in a wide range of formats. The learning materials include interactive activities, assessments, and feedback.
Courses delivered using network or Internet resources are often called online learning experiences, or e-learning.
The availability of e-learning courseware has multiplied the resources available to students many times over. Traditional learning methods provide primarily two sources of expertise from which the student can obtain information: the textbook and the instructor. These two sources are limited, both in the format and the timing of the presentation. In contrast, online courses can contain voice, data, and video, and are available to the students at any time from any place. Students can follow links to different references and to subject experts in order to enhance their learning experience. Online discussion groups and message boards enable a student to collaborate with the instructor, with other students in the class, or even with students across the world. Blended courses can combine instructor-led classes with online courseware to provide the best of both delivery methods.
Access to high quality instruction is no longer restricted to students living in proximity to where that instruction is being delivered. Online distance learning has removed geographic barriers and improved student opportunity.
Courses delivered using network or Internet resources are often called online learning experiences, or e-learning.
The availability of e-learning courseware has multiplied the resources available to students many times over. Traditional learning methods provide primarily two sources of expertise from which the student can obtain information: the textbook and the instructor. These two sources are limited, both in the format and the timing of the presentation. In contrast, online courses can contain voice, data, and video, and are available to the students at any time from any place. Students can follow links to different references and to subject experts in order to enhance their learning experience. Online discussion groups and message boards enable a student to collaborate with the instructor, with other students in the class, or even with students across the world. Blended courses can combine instructor-led classes with online courseware to provide the best of both delivery methods.
Access to high quality instruction is no longer restricted to students living in proximity to where that instruction is being delivered. Online distance learning has removed geographic barriers and improved student opportunity.
Examples of Today's Popular
The existence and broad adoption of the Internet has ushered in new forms of communication that empower individuals to create information that can be accessed by a global audience.
Instant Messaging
Instant messaging (IM) is a form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over either a private internal network or over a public network, such as the Internet. Developed from earlier Internet Relay Chat (IRC) services, IM also incorporates features such as file transfer, voice, and video communication. Like e-mail, IM sends a written record of the communication. However, whereas transmission of e-mail messages is sometimes delayed, IM messages are received immediately. The form of communication that IM uses is called real-time communication.
Weblogs (blogs)
Weblogs (Blogs) are web pages that are easy to update and edit. Unlike commercial websites, which are created by professional communications experts, blogs give anyone a means to communicate their thoughts to a global audience without technical knowledge of web design. There are blogs on nearly every topic one can think of, and communities of people often form around popular blog authors.
Wikis
Wikis are web pages that groups of people can edit and view together. Whereas a blog is more of an individual, personal journal, a wiki is a group creation. As such, it may be subject to more extensive review and editing. Like blogs, wikis can be created in stages, and by anyone, without the sponsorship of a major commercial enterprise. There is a public wiki, called Wikipedia, that is becoming a comprehensive resource - an online encyclopedia - of publicly-contributed topics. Private organizations and individuals can also build their own wikis to capture collected knowledge on a particular subject. Many businesses use wikis as their internal collaboration tool. With the global Internet, people of all walks of life can participate in wikis and add their own perspectives and knowledge to a shared resource.
Podcasting
Podcasting is an audio-based medium that originally enabled people to record audio and convert it for use with iPods - a small, portable device for audio playback manufactured by Apple. The ability to record audio and save it to a computer file is not new. However, podcasting allows people to deliver their recordings to a wide audience. The audio file is placed on a website (or blog or wiki) where others can download it and play the recording on their computers, laptops, and iPods.
Collaboration Tools
Collaboration tools give people the opportunity to work together on shared documents. Without the constraints of location or time zone, individuals connected to a shared system can speak to each other, share text and graphics, and edit documents together. With collaboration tools always available, organizations can move quickly to share information and pursue goals. The broad distribution of data networks means that people in remote locations can contribute on an equal basis with people at the heart of large population centers.
Instant Messaging
Instant messaging (IM) is a form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over either a private internal network or over a public network, such as the Internet. Developed from earlier Internet Relay Chat (IRC) services, IM also incorporates features such as file transfer, voice, and video communication. Like e-mail, IM sends a written record of the communication. However, whereas transmission of e-mail messages is sometimes delayed, IM messages are received immediately. The form of communication that IM uses is called real-time communication.
Weblogs (blogs)
Weblogs (Blogs) are web pages that are easy to update and edit. Unlike commercial websites, which are created by professional communications experts, blogs give anyone a means to communicate their thoughts to a global audience without technical knowledge of web design. There are blogs on nearly every topic one can think of, and communities of people often form around popular blog authors.
Wikis
Wikis are web pages that groups of people can edit and view together. Whereas a blog is more of an individual, personal journal, a wiki is a group creation. As such, it may be subject to more extensive review and editing. Like blogs, wikis can be created in stages, and by anyone, without the sponsorship of a major commercial enterprise. There is a public wiki, called Wikipedia, that is becoming a comprehensive resource - an online encyclopedia - of publicly-contributed topics. Private organizations and individuals can also build their own wikis to capture collected knowledge on a particular subject. Many businesses use wikis as their internal collaboration tool. With the global Internet, people of all walks of life can participate in wikis and add their own perspectives and knowledge to a shared resource.
Podcasting
Podcasting is an audio-based medium that originally enabled people to record audio and convert it for use with iPods - a small, portable device for audio playback manufactured by Apple. The ability to record audio and save it to a computer file is not new. However, podcasting allows people to deliver their recordings to a wide audience. The audio file is placed on a website (or blog or wiki) where others can download it and play the recording on their computers, laptops, and iPods.
Collaboration Tools
Collaboration tools give people the opportunity to work together on shared documents. Without the constraints of location or time zone, individuals connected to a shared system can speak to each other, share text and graphics, and edit documents together. With collaboration tools always available, organizations can move quickly to share information and pursue goals. The broad distribution of data networks means that people in remote locations can contribute on an equal basis with people at the heart of large population centers.
Networks Supporting the Way We Live3
It is incredible how quickly the Internet became an integral part of our daily routines. The complex interconnection of electronic devices and media that comprise the network is transparent to the millions of users who make it a valued and personal part of their lives.
Data networks that were once the transport of information from business to business have been repurposed to improve the quality of life for people everywhere. In the course of a day, resources available through the Internet can help you:
Decide what to wear using online current weather conditions.
Find the least congested route to your destination, displaying weather and traffic video from webcams.
Check your bank balance and pay bills electronically.
Receive and send e-mail, or make an Internet phone call, at an Internet cafe over lunch.
Obtain health information and nutritional advice from experts all over the world, and post to a forum to share related health or treatment information.
Download new recipes and cooking techniques to create a spectacular dinner.
Post and share your photographs, home videos, and experiences with friends or with the world.
Many uses of the Internet would have been hard to imagine just a few years ago. Take for example, one person's experience publishing a home music video:
"My goal is to make my own movies. One day, my friend Adi and I made a video as a surprise for her boyfriend's birthday. We recorded ourselves lip-synching to a song and dancing around. Then we decided, why not post it. Well, the reaction has been huge. It's had over 9 million views so far, and the movie director Kevin Smith even did a short spoof of it. I don't know what draws people to the video. Maybe it's the simplicity of it, or the song. Maybe it's because it's spontaneous and fun, and it makes people feel good. I don't know. But I do know that I can do what I love and share it online with millions of people around the world. All I need is my computer, digital camcorder, and some software. And that's an amazing thing."
Data networks that were once the transport of information from business to business have been repurposed to improve the quality of life for people everywhere. In the course of a day, resources available through the Internet can help you:
Decide what to wear using online current weather conditions.
Find the least congested route to your destination, displaying weather and traffic video from webcams.
Check your bank balance and pay bills electronically.
Receive and send e-mail, or make an Internet phone call, at an Internet cafe over lunch.
Obtain health information and nutritional advice from experts all over the world, and post to a forum to share related health or treatment information.
Download new recipes and cooking techniques to create a spectacular dinner.
Post and share your photographs, home videos, and experiences with friends or with the world.
Many uses of the Internet would have been hard to imagine just a few years ago. Take for example, one person's experience publishing a home music video:
"My goal is to make my own movies. One day, my friend Adi and I made a video as a surprise for her boyfriend's birthday. We recorded ourselves lip-synching to a song and dancing around. Then we decided, why not post it. Well, the reaction has been huge. It's had over 9 million views so far, and the movie director Kevin Smith even did a short spoof of it. I don't know what draws people to the video. Maybe it's the simplicity of it, or the song. Maybe it's because it's spontaneous and fun, and it makes people feel good. I don't know. But I do know that I can do what I love and share it online with millions of people around the world. All I need is my computer, digital camcorder, and some software. And that's an amazing thing."
Networks Supporting the Way We Live2
The Global Community
Technology is perhaps the most significant change agent in the world today, as it helps to create a world in which national borders, geographic distances, and physical limitations become less relevant, and present ever-diminishing obstacles. The creation of online communities for the exchange of ideas and information has the potential to increase productivity opportunities across the globe. As the Internet connects people and promotes unfettered communication, it presents the platform on which to run businesses, to address emergencies, to inform individuals, and to support education, science, and government.
Technology is perhaps the most significant change agent in the world today, as it helps to create a world in which national borders, geographic distances, and physical limitations become less relevant, and present ever-diminishing obstacles. The creation of online communities for the exchange of ideas and information has the potential to increase productivity opportunities across the globe. As the Internet connects people and promotes unfettered communication, it presents the platform on which to run businesses, to address emergencies, to inform individuals, and to support education, science, and government.
Networks Supporting the Way We Live
Among all of the essentials for human existence, the need to interact with others ranks just below our need to sustain life. Communication is almost as important to us as our reliance on air, water, food, and shelter.
The methods that we use to share ideas and information are constantly changing and evolving. Whereas the human network was once limited to face-to-face conversations, media breakthroughs continue to extend the reach of our communications. From the printing press to television, each new development has improved and enhanced our communication.
As with every advance in communication technology, the creation and interconnection of robust data networks is having a profound effect.
Early data networks were limited to exchanging character-based information between connected computer systems. Current networks have evolved to carry voice, video streams, text, and graphics between many different types of devices. Previously separate and distinct communication forms have converged onto a common platform. This platform provides access to a wide range of alternative and new communication methods that enable people to interact directly with each other almost instantaneously.
The immediate nature of communications over the Internet encourages the formation of global communities. These communities foster social interaction that is independent of location or time zone.
The methods that we use to share ideas and information are constantly changing and evolving. Whereas the human network was once limited to face-to-face conversations, media breakthroughs continue to extend the reach of our communications. From the printing press to television, each new development has improved and enhanced our communication.
As with every advance in communication technology, the creation and interconnection of robust data networks is having a profound effect.
Early data networks were limited to exchanging character-based information between connected computer systems. Current networks have evolved to carry voice, video streams, text, and graphics between many different types of devices. Previously separate and distinct communication forms have converged onto a common platform. This platform provides access to a wide range of alternative and new communication methods that enable people to interact directly with each other almost instantaneously.
The immediate nature of communications over the Internet encourages the formation of global communities. These communities foster social interaction that is independent of location or time zone.
Chapter Introduction
We now stand at a critical turning point in the use of technology to extend and empower our human network. The globalization of the Internet has succeeded faster than anyone could have imagined. The manner in which social, commercial, political and personal interactions occur is rapidly changing to keep up with the evolution of this global network. In the next stage of our development, innovators will use the Internet as a starting point for their efforts - creating new products and services specifically designed to take advantage of the network capabilities. As developers push the limits of what is possible, the capabilities of the interconnected networks that form the Internet will play an increasing role in the success of these projects.
This chapter introduces the platform of data networks upon which our social and business relationships increasingly depend. The material lays the groundwork for exploring the services, technologies, and issues encountered by network professionals as they design, build, and maintain the modern network.
In this chapter, you will learn to:
Describe how networks impact our daily lives.
Describe the role of data networking in the human network.
Identify the key components of any data network.
Identify the opportunities and challenges posed by converged networks.
Describe the characteristics of network architectures: fault tolerance, scalability, quality of service and security.
Install and use IRC clients and a Wikiserver.
This chapter introduces the platform of data networks upon which our social and business relationships increasingly depend. The material lays the groundwork for exploring the services, technologies, and issues encountered by network professionals as they design, build, and maintain the modern network.
In this chapter, you will learn to:
Describe how networks impact our daily lives.
Describe the role of data networking in the human network.
Identify the key components of any data network.
Identify the opportunities and challenges posed by converged networks.
Describe the characteristics of network architectures: fault tolerance, scalability, quality of service and security.
Install and use IRC clients and a Wikiserver.
Message To Students
3. Practice. Learning new skills requires practice. We believe this is so important to e-learning that we have a special name for it. We call it e-Doing. It is very important that you complete the activities in the online instructional materials and that you also complete the hands-on labs and Packet Tracer activities.
4. Practice again. Have you ever thought that you knew how to do something and then, when it was time to show it on a test or at work, you discovered that you really hadn’t mastered it? Just like learning any new skill like a sport, game, or language, learning a professional skill requires patience and repeated practice before you can say you have truly learned it. The online instructional materials in this course provide opportunities for repeated practice for many skills. Take full advantage of them. You can also work with your instructor to extend Packet Tracer, and other tools, for additional practice as needed.
5. Teach it. Teaching a friend or colleague is often a good way to reinforce your own learning. To teach well, you will have to work through details that you may have overlooked on your first reading. Conversations about the course material with fellow students, colleagues, and the instructor can help solidify your understanding of networking concepts.
6. Make changes as you go. The course is designed to provide feedback through interactive activities and quizzes, the online assessment system, and through structured interactions with your instructor. You can use this feedback to better understand where your strengths and weaknesses are. If there is an area that you are having trouble with, focus on studying or practicing more in that area. Seek additional feedback from your instructor and other students.
Explore the world of networking
This version of the course includes a special tool called Packet Tracer 4.1. Packet Tracer is a networking learning tool that supports a wide range of physical and logical simulations. It also provides visualization tools to help you to understand the internal workings of a network.
The pre-made Packet Tracer activities consist of network simulations, games, activities, and challenges that provide a broad range of learning experiences.
Create your own worlds
You can also use Packet Tracer to create your own experiments and networking scenarios. We hope that, over time, you consider using Packet Tracer – not only for experiencing the pre-built activities, but also to become an author, explorer, and experimenter.
The online course materials have embedded Packet Tracer activities that will launch on computers running Windows® operating systems, if Packet Tracer is installed. This integration may also work on other operating systems using Windows emulation.
Explore the world of networking
This version of the course includes a special tool called Packet Tracer 4.1. Packet Tracer is a networking learning tool that supports a wide range of physical and logical simulations. It also provides visualization tools to help you to understand the internal workings of a network.
The pre-made Packet Tracer activities consist of network simulations, games, activities, and challenges that provide a broad range of learning experiences.
Create your own worlds
You can also use Packet Tracer to create your own experiments and networking scenarios. We hope that, over time, you consider using Packet Tracer – not only for experiencing the pre-built activities, but also to become an author, explorer, and experimenter.
The online course materials have embedded Packet Tracer activities that will launch on computers running Windows® operating systems, if Packet Tracer is installed. This integration may also work on other operating systems using Windows emulation.
Course Overview Continued
Chapter 6 - In Chapter 6, you will focus on network addressing in detail and learn how to use the address mask, or prefix length, to determine the number of subnetworks and hosts in a network. You will also be introduced to ICMP (Internet Control Message Protocol) tools, such as ping and trace.
Chapter 7 – Chapter 7 discusses the services provided by Data Link layer. An emphasis is placed on the encapsulation processes that occur as data travels across the LAN and the WAN.
Chapter 8 – Chapter 8 introduces the Physical layer. You will discover how data sends signals and is encoded for travel across the network. You’ll learn about bandwidth and also about the types of media and their associated connectors.
Chapter 9 – In Chapter 9, you will examine the technologies and operation of Ethernet. You will use Wireshark®, Packet Tracer activities, and lab exercises to explore Ethernet.
Chapter 10 – Chapter 10 focuses on designing and cabling a network. You will apply the knowledge and skills developed in the previous chapters to determine the appropriate cables to use, how to connect devices, and develop an addressing and testing scheme.
Chapter 11 –In Chapter 11, you will connect and configure a small network using basic Cisco IOS commands for routers and switches. Upon completion of this final chapter, you will be prepared you to go on to either CCNA Exploration Routing or CCNA Exploration Switching courses.
4. Practice again. Have you ever thought that you knew how to do something and then, when it was time to show it on a test or at work, you discovered that you really hadn’t mastered it? Just like learning any new skill like a sport, game, or language, learning a professional skill requires patience and repeated practice before you can say you have truly learned it. The online instructional materials in this course provide opportunities for repeated practice for many skills. Take full advantage of them. You can also work with your instructor to extend Packet Tracer, and other tools, for additional practice as needed.
5. Teach it. Teaching a friend or colleague is often a good way to reinforce your own learning. To teach well, you will have to work through details that you may have overlooked on your first reading. Conversations about the course material with fellow students, colleagues, and the instructor can help solidify your understanding of networking concepts.
6. Make changes as you go. The course is designed to provide feedback through interactive activities and quizzes, the online assessment system, and through structured interactions with your instructor. You can use this feedback to better understand where your strengths and weaknesses are. If there is an area that you are having trouble with, focus on studying or practicing more in that area. Seek additional feedback from your instructor and other students.
Explore the world of networking
This version of the course includes a special tool called Packet Tracer 4.1. Packet Tracer is a networking learning tool that supports a wide range of physical and logical simulations. It also provides visualization tools to help you to understand the internal workings of a network.
The pre-made Packet Tracer activities consist of network simulations, games, activities, and challenges that provide a broad range of learning experiences.
Create your own worlds
You can also use Packet Tracer to create your own experiments and networking scenarios. We hope that, over time, you consider using Packet Tracer – not only for experiencing the pre-built activities, but also to become an author, explorer, and experimenter.
The online course materials have embedded Packet Tracer activities that will launch on computers running Windows® operating systems, if Packet Tracer is installed. This integration may also work on other operating systems using Windows emulation.
Explore the world of networking
This version of the course includes a special tool called Packet Tracer 4.1. Packet Tracer is a networking learning tool that supports a wide range of physical and logical simulations. It also provides visualization tools to help you to understand the internal workings of a network.
The pre-made Packet Tracer activities consist of network simulations, games, activities, and challenges that provide a broad range of learning experiences.
Create your own worlds
You can also use Packet Tracer to create your own experiments and networking scenarios. We hope that, over time, you consider using Packet Tracer – not only for experiencing the pre-built activities, but also to become an author, explorer, and experimenter.
The online course materials have embedded Packet Tracer activities that will launch on computers running Windows® operating systems, if Packet Tracer is installed. This integration may also work on other operating systems using Windows emulation.
Course Overview Continued
Chapter 6 - In Chapter 6, you will focus on network addressing in detail and learn how to use the address mask, or prefix length, to determine the number of subnetworks and hosts in a network. You will also be introduced to ICMP (Internet Control Message Protocol) tools, such as ping and trace.
Chapter 7 – Chapter 7 discusses the services provided by Data Link layer. An emphasis is placed on the encapsulation processes that occur as data travels across the LAN and the WAN.
Chapter 8 – Chapter 8 introduces the Physical layer. You will discover how data sends signals and is encoded for travel across the network. You’ll learn about bandwidth and also about the types of media and their associated connectors.
Chapter 9 – In Chapter 9, you will examine the technologies and operation of Ethernet. You will use Wireshark®, Packet Tracer activities, and lab exercises to explore Ethernet.
Chapter 10 – Chapter 10 focuses on designing and cabling a network. You will apply the knowledge and skills developed in the previous chapters to determine the appropriate cables to use, how to connect devices, and develop an addressing and testing scheme.
Chapter 11 –In Chapter 11, you will connect and configure a small network using basic Cisco IOS commands for routers and switches. Upon completion of this final chapter, you will be prepared you to go on to either CCNA Exploration Routing or CCNA Exploration Switching courses.
Mind Wide Open
Mind Wide Open™
An important goal in education is to enrich you, the student, by expanding what you know and can do. It is important to realize, however, that the instructional materials and the instructor can only facilitate the process. You must make the commitment yourself to learn new skills. Below are a few suggestions to help you learn and grow.
1. Take notes. Professionals in the networking field often keep Engineering Journals in which they write down the things they observe and learn. Taking notes is an important way to help your understanding grow over time.
2. Think about it. The course provides information both to change what you know and what you can do. As you go through the course, ask yourself what makes sense and what doesn’t. Stop and ask questions when you are confused. Try to find out more about topics that interest you. If you are not sure why something is being taught, consider asking your instructor or a friend. Think about how the different parts of the course fit together.
An important goal in education is to enrich you, the student, by expanding what you know and can do. It is important to realize, however, that the instructional materials and the instructor can only facilitate the process. You must make the commitment yourself to learn new skills. Below are a few suggestions to help you learn and grow.
1. Take notes. Professionals in the networking field often keep Engineering Journals in which they write down the things they observe and learn. Taking notes is an important way to help your understanding grow over time.
2. Think about it. The course provides information both to change what you know and what you can do. As you go through the course, ask yourself what makes sense and what doesn’t. Stop and ask questions when you are confused. Try to find out more about topics that interest you. If you are not sure why something is being taught, consider asking your instructor or a friend. Think about how the different parts of the course fit together.
Friday, October 2, 2009
#10
Brutus : A network brute-force authentication cracker
This Windows-only cracker bangs against network services of remote systems trying to guess passwords by using a dictionary and permutations thereof. It supports HTTP, POP3, FTP, SMB, TELNET, IMAP, NTP, and more. No source code is available. UNIX users should take a look at THC Hydra.
Brutus : A network brute-force authentication crackerThis Windows-only cracker bangs against network services of remote systems trying to guess passwords by using a dictionary and permutations thereof. It supports HTTP, POP3, FTP, SMB, TELNET, IMAP, NTP, and more. No source code is available. UNIX users should take a look at THC Hydra.
#9
RainbowCrack : An Innovative Password Hash Cracker
The RainbowCrack tool is a hash cracker that makes use of a large-scale time-memory trade-off. A traditional brute force cracker tries all possible plaintexts one by one, which can be time consuming for complex passwords. RainbowCrack uses a time-memory trade-off to do all the cracking-time computation in advance and store the results in so-called "rainbow tables". It does take a long time to precompute the tables but RainbowCrack can be hundreds of times faster than a brute force cracker once the precomputation is finished.
RainbowCrack : An Innovative Password Hash CrackerThe RainbowCrack tool is a hash cracker that makes use of a large-scale time-memory trade-off. A traditional brute force cracker tries all possible plaintexts one by one, which can be time consuming for complex passwords. RainbowCrack uses a time-memory trade-off to do all the cracking-time computation in advance and store the results in so-called "rainbow tables". It does take a long time to precompute the tables but RainbowCrack can be hundreds of times faster than a brute force cracker once the precomputation is finished.
#8
Pwdump : A window password recovery tool
Pwdump is able to extract NTLM and LanMan hashes from a Windows target, regardless of whether Syskey is enabled. It is also capable of displaying password histories if they are available. It outputs the data in L0phtcrack-compatible form, and can write to an output file.
Pwdump : A window password recovery toolPwdump is able to extract NTLM and LanMan hashes from a Windows target, regardless of whether Syskey is enabled. It is also capable of displaying password histories if they are available. It outputs the data in L0phtcrack-compatible form, and can write to an output file.
#7
SolarWinds : A plethora of network discovery/monitoring/attack tools
SolarWinds has created and sells dozens of special-purpose tools targeted at systems administrators. Security-related tools include many network discovery scanners, an SNMP brute-force cracker, router password decryption, a TCP connection reset program, one of the fastest and easiest router config download/upload applications available and more.
SolarWinds : A plethora of network discovery/monitoring/attack toolsSolarWinds has created and sells dozens of special-purpose tools targeted at systems administrators. Security-related tools include many network discovery scanners, an SNMP brute-force cracker, router password decryption, a TCP connection reset program, one of the fastest and easiest router config download/upload applications available and more.
Also categorized as: traffic monitoring tools
#6
Airsnort : 802.11 WEP Encryption Cracking Tool
AirSnort is a wireless LAN (WLAN) tool that recovers encryption keys. It was developed by the Shmoo Group and operates by passively monitoring transmissions, computing the encryption key when enough packets have been gathered. You may also be interested in the similar Aircrack.
Airsnort : 802.11 WEP Encryption Cracking ToolAirSnort is a wireless LAN (WLAN) tool that recovers encryption keys. It was developed by the Shmoo Group and operates by passively monitoring transmissions, computing the encryption key when enough packets have been gathered. You may also be interested in the similar Aircrack.
Also categorized as: wireless tools
#5
L0phtcrack : Windows password auditing and recovery application
L0phtCrack, also known as LC5, attempts to crack Windows passwords from hashes which it can obtain (given proper access) from stand-alone Windows NT/2000 workstations, networked servers, primary domain controllers, or Active Directory. In some cases it can sniff the hashes off the wire. It also has numerous methods of generating password guesses (dictionary, brute force, etc). LC5 was discontinued by Symantec in 2006, but you can still find the LC5 installer floating around. The free trial only lasts 15 days, and Symantec won't sell you a key, so you'll either have to cease using it or find a key generator. Since it is no longer maintained, you are probably better off trying Cain and Abel, John the Ripper, or Ophcrack instead.
L0phtcrack : Windows password auditing and recovery applicationL0phtCrack, also known as LC5, attempts to crack Windows passwords from hashes which it can obtain (given proper access) from stand-alone Windows NT/2000 workstations, networked servers, primary domain controllers, or Active Directory. In some cases it can sniff the hashes off the wire. It also has numerous methods of generating password guesses (dictionary, brute force, etc). LC5 was discontinued by Symantec in 2006, but you can still find the LC5 installer floating around. The free trial only lasts 15 days, and Symantec won't sell you a key, so you'll either have to cease using it or find a key generator. Since it is no longer maintained, you are probably better off trying Cain and Abel, John the Ripper, or Ophcrack instead.
#4
Aircrack : The fastest available WEP/WPA cracking tool
Aircrack is a suite of tools for 802.11a/b/g WEP and WPA cracking. It can recover a 40 through 512-bit WEP key once enough encrypted packets have been gathered. It can also attack WPA 1 or 2 networks using advanced cryptographic methods or by brute force. The suite includes airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), and airdecap (decrypts WEP/WPA capture files).
Aircrack : The fastest available WEP/WPA cracking toolAircrack is a suite of tools for 802.11a/b/g WEP and WPA cracking. It can recover a 40 through 512-bit WEP key once enough encrypted packets have been gathered. It can also attack WPA 1 or 2 networks using advanced cryptographic methods or by brute force. The suite includes airodump (an 802.11 packet capture program), aireplay (an 802.11 packet injection program), aircrack (static WEP and WPA-PSK cracking), and airdecap (decrypts WEP/WPA capture files).
Also categorized as: wireless tools
#3
THC Hydra : A Fast network authentication cracker which support many different services
When you need to brute force crack a remote authentication service, Hydra is often the tool of choice. It can perform rapid dictionary attacks against more then 30 protocols, including telnet, ftp, http, https, smb, several databases, and much more. Like THC Amap this release is from the fine folks at THC.
THC Hydra : A Fast network authentication cracker which support many different servicesWhen you need to brute force crack a remote authentication service, Hydra is often the tool of choice. It can perform rapid dictionary attacks against more then 30 protocols, including telnet, ftp, http, https, smb, several databases, and much more. Like THC Amap this release is from the fine folks at THC.
Top 10 Password Crackers
| #1 |  Cain and Abel : The top password recovery tool for WindowsUNIX users often smugly assert that the best free security tools support their platform first, and Windows ports are often an afterthought. They are usually right, but Cain & Abel is a glaring exception. This Windows-only password recovery tool handles an enormous variety of tasks. It can recover passwords by sniffing the network, cracking encrypted passwords using Dictionary, Brute-Force and Cryptanalysis attacks, recording VoIP conversations, decoding scrambled passwords, revealing password boxes, uncovering cached passwords and analyzing routing protocols. It is also well documented. Also categorized as: packet sniffers |
| #2 |  John the Ripper : A powerful, flexible, and fast multi-platform password hash crackerJohn the Ripper is a fast password cracker, currently available for many flavors of Unix (11 are officially supported, not counting different architectures), DOS, Win32, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types which are most commonly found on various Unix flavors, as well as Kerberos AFS and Windows NT/2000/XP LM hashes. Several other hash types are added with contributed patches. You will want to start with some wordlists, which you can find here, here, or here. |
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