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دورة سيسكو(ccna)

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  1. [61]
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    تاريخ التسجيل: May 2006
    المشاركات: 119
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    السلام عليكم و رحمة الله
    اذا كان المقصود بالبرنامج الopnet فيجب بعد الا نتهاء من تنزيله أن تفعّله ،هذا جزء من e-mailوصلني يجب ان يكون وصلك منهم مثله ،If you do not already have the IT Guru Academic Edition installer,
    download
    the software from here:
    http://www.opnet.com/itguru-academic/download.html

    Once you have downloaded the installer, run it to install the software.
    Then run the software, which will guide you through the product
    activation
    process.

    For additional information related to IT Guru Academic Edition,
    including
    FAQs:
    http://www.opnet.com/itguru-academic/home.html

    من هذا الرابط بفتحلك صفحة في اخرها مكتوب
    Running the software for the first time...step by step instructions
    و بذكر انه لازم تكون مسجل لأنه رح يطلبك كلمة السر على العموم اتبع الخطوات و هو بوضحلك .
    ان شاء الله ما اكون عقّدتها، و ارجو الفائدة للجميع

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  2. [62]
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    تاريخ التسجيل: May 2006
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    هذه الخطوات
    Step-by-step process
    for activating IT Guru Academic Edition When you run IT Guru Academic Edition for the first time, its license needs to be activated. By following these steps you should be able to satisfactorily complete the activation process.
    Note: if you have not already downloaded and installed the software, please follow the instructions at www.opnet.com/itguru-academic/download.html.
    In the following process you will need to switch between your web browser and IT Guru Academic Edition.
    Step 1.
    Start IT Guru Academic Edition Step 2.
    Click on License ManagementStep 3.
    Click on NextStep 4.
    Enter User Name and Password into the prompt dialog displayed by your web browser, and click OK

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  3. [63]
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    تاريخ التسجيل: May 2006
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    Step 5.
    In IT Guru Academic Edition, click on Copy to ClipboardStep 6.
    In your web browser, paste the License Request Code
    Step 7.
    Click on Submit
    Step 8.
    In your web browser, copy the Approval Code to the clipboardStep 9.
    In IT Guru Academic Edition, click on NextStep 10.
    In IT Guru Academic Edition, click on Paste from Clipboard
    Step 11.
    Click on Next
    Step 12.
    Click on CloseStep 13.
    Restart IT Guru Academic Edition

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  4. [64]
    ياسين2999
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    تاريخ التسجيل: Apr 2006
    المشاركات: 344
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    السلام عليكم ,
    شكرا مررررررررة كثير على هذا الرد سأفعل حسب ما تفضلتي ,
    شكرا مرة ثانية ,
    ياسين .

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  5. [65]
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    تاريخ التسجيل: May 2006
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    Chapter Three

    Cisco Router Network Design

    The hierarchical structure of the Cisco router network design model is based on the type of services provided at each layer. The notion of using layers creates a modular architecture enabling growth and flexibility for new technologies at each layer. The Cisco hierarchical design model consists of three layers. Figure 3.1 diagrams the Cisco hierarchical design model.
    The core layer provides the high-speed backbone for moving data between the other layers. This layer is geared towards the delivery of packets and not packet inspection or manipulation.
    The distribution layer provided policy-based networking between the core and access layer. The distribution layer provides boundaries to the network topology and provides several services. These services are:
    • Address or area aggregation
    • Departmental or workgroup access
    • Broadcast/multicast domain definition
    • Virtual LAN (VLAN) routing
    • Any media transitions that need to occur
    • Security
    The access layer is the edge of the network. Being on the edge the access layer is the entry point to the network for the end user community. Devices participating in the access layer may perform the following functions:
    • Shared bandwidth
    • Switched bandwidth
    • MAC layer filtering
    • Microsegmentation
    It is important to remember that the Cisco hierarchical design model addresses functional services of a network. The different layers described may be found in routers or switches. Each device may partake in the functions of more than one layer. Separation of functional layers is not mandatory however; maintaining a hierarchical design fosters a network optimized for performance and management.
      1. The Network Infrastructure Life-Cycle
    Every corporation has a network infrastructure in place as the framework supporting the business processes. Just as applications and systems have life cycles so does a network infrastructure. This section highlights a network infrastructure life-cycle that may be used as a general guideline for designing and implementing Cisco based networks.
        1. Executive Corporate Vision
    Corporate organizational restructuring through regional consolidation or through business group integration will certainly have an effect on the network infrastructure. Aligning the corporate vision with the business directives builds the foundation for the network infrastructure.

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  6. [66]
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    تاريخ التسجيل: May 2006
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        1. Gather Network Infrastructure Information
    This involves research and discovery of the current network WAN topology as well as corporate and branch office LAN topologies. A full understanding of end-to-end network configuration is required. Additionally, bandwidth allocations and usage costs must be determined to provide the complete picture.
        1. Determine current network requirements
    Communication protocols, client/server architectures, e-mail, distributed processing, Inter— and Intranet, voice and video, each has its own unique characteristics and can place demands on the network. These demands have to be recognized and understood for planning an enterprise wide solution. The result from this study is a network profile for each business process and the network itself.
        1. Assess current network operational processes
    Network operational processes involve not just daily trouble shooting but the other disciplines of network management: Inventory, Change, Configuration, Fault, Security, Capacity/Performance, and Accounting. Documenting the processes in place today will assist in evaluating the current baseline of service provided and identify areas that may need re-engineering to meet the changing business requirements.
        1. Research plans for new applications
    The effect of new applications on network characteristics must be discovered prior to business groups moving into development, testing and production. Desktop video conferencing and voice communications along with data traffic requires up front knowledge to re-engineer a network. Business group surveys and interviews along with each group's strategic plan will provide input to creating a requirements matrix.
        1. Identify networking technologies
    The selection of the appropriate technologies and how they can be of use in meeting current and future networking requirements relies on vendor offerings and their support structure. Paramount to this success is the partnership with and management of the vendors through an agreed on working relationship.
        1. Define a flexible strategic/tactical plan
    The strategic plan in today’s fast pace changing technology environment requires flexibility. A successful strategic plan requires business continuity through tactical choices. The strategic plan must demonstrate networking needs in relation to business processes both current and future.
        1. Develop Implementation Plan
    This is the most visible of all the previous objectives. The planning and research performed prior can be for naught if the implementation does not protect current business processes from unscheduled outages. This must meet current business requirements and demands while migrating the network infrastructure to the strategic/tactical design. The perception to the business community must be business as usual.
        1. Management and Review
    The effectiveness of the new infrastructure is achieved through management and review. Reports highlighting the network health measured against expected service levels based on the strategic/tactical plan and design reflect the ability of the network to meet business objectives. The tools and analysis used here provide the basis for future network infrastructures.

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  7. [67]
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    تاريخ التسجيل: May 2006
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      1. Design Criteria (Design Internet Basics)
    In planning for your network design there are many criteria to consider. These criteria are based on the current network design and performance requirements as measured against the business direction compared to internetworking design trends. The trends of internetworking design affect the four distinct components of an enterprise internetwork. These components are:
    Local Area Networks - These are networks within a single location that connect local end users to the services provided by the entire enterprise network.
    Campus networks - These are networks within a small geographic area interconnecting the buildings that make up the corporate or business entity for the area.
    Wide-area networks (WAN) - These networks span large geographic areas and interconnect campus networks.
    Remote networks - These types of networks connect branch offices, mobile users or telecommuters to a campus or the Internet.
    Figure 3.2 illustrates today's typical enterprise-wide corporate network topology.
        1. The Current LAN/Campus Trend
    LANs and Campus networks are grouped together for the simple reason that they share many of the same networking issues and requirements. Depending on technologies used a LAN may be focused within a building or span buildings. The spanning of a LAN makes up the campus network. Figure 3.3 diagrams a LAN/Campus network topology.
    Campus networks are a hybrid of LANs and WANs. From LAN/WAN technologies campus networks use Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI) Fast Ethernet, Gigabit Ethernet and Asynchronous Transfer Mode (ATM).
    Two LAN technologies that serve to optimize bandwidth and increase flexibility for LAN design are Layer 2 and Layer 3 switching. In short, Layer 2 switching occurs at the data link layer of the OSI Reference Model and Layer 3 switching occurs at the Network layer of the OSI reference Model. Both switching algorithms increase performance by providing higher bandwidth to attached workgroups, local servers and workstations. The switches replace LAN hubs and concentrators in the wiring closets of the building.
    The ability to switch end user traffic between ports on the device has enabled the concept of Virtual LANs (VLANs). Defining VLANs on the physical LAN enables logical groupings of end user segments or workstations. This enables traffic specific to this VLAN grouping to remain on this virtual LAN rather than use bandwidth on LAN segments that are not interested in the grouped traffic. For example, the Finance VLAN traffic does not affect the Engineering VLAN traffic. Table 3.x lists the important technologies affecting LAN and Campus network design.

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  8. [68]
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    تاريخ التسجيل: May 2006
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    Routing technologies
    Routing has long been the basis for creating internetworks. For use in a LAN/Campus environment, routing can be combined with Layer 3 switching. Layer 3 switching may also replace the entire function of a router.

    LAN switching technologies
    Ethernet switching
    Ethernet switching is Layer 2 switching. Layer 2 switching can enable improved performance through dedicated Ethernet segments for each connection.

    Token Ring switching
    Token Ring switching is also Layer 2 switching. Switching token-ring segments offers the same functionality as Ethernet switching. Token Ring switching operates as either a transparent bridge or a source-route bridge.

    ATM switching technologies
    ATM switching offers high-speed switching technology that integrates voice, video, and data. Its operation is similar to LAN switching technologies for data operations.
        1. Wide Area Network Design Trends
    Routers are typically the connection points to WANs. Being at this juncture, the routers have become an important decision point for the delivery of traffic. With the advent of switching the routers are slowly moving away from being the WAN device. The WAN services are now being handled by switches with three types of switching technologies. These are circuit, packet and cell switching.
    Circuits switching provides dedicated bandwidth while packet switched enabled efficient use of bandwidth with flexibility to service multiple requirements. Cell switching combines the best of both circuit and packet switched networks. ATM is the leading cell-switched technology used in the WAN today.
    Because the WAN links end up servicing all traffic from one location to another, it is important that the bandwidth and performance be optimized. The optimization is due in part to the explosive growth of remote site connectivity, enhanced application architectures such as, client/server and intranets, and the recent development of consolidating servers to a centralized location to ease administration and management. These factors have reversed the rules for traffic profiles form that of 80% LAN and 20 % WAN to 80 % WAN and 20% LAN. This flip-flop of traffic characteristics has increased the requirement for WAN traffic optimization, path redundancy, dial backup and Quality of Service (QoS) to ensure application service levels over the WAN. The technologies available today that enable effective and efficient use of WANs are summarized in Table 3.x. Coming on the horizon are such technologies as: Digital Subscriber Line (DSL), Low-Earth Orbit (LEO) satellites, and advanced wireless technologies.
    WAN Technology
    Typical Uses

    Analog modem
    Analog modems are typically used for temporary dial-up connections or for backup of another type of link. The bandwidth is typically 9.6bps - 56 Kbps.

    Leased line
    Leased lines have been the traditional technology for implementing WANs. These are links "leased" from communications services companies for exclusive use by your corporation.

    Integrated Services Digital Network (ISDN)
    ISDN is a dial-up solution for temporary access to the WAN but adds the advantage of supporting voice/video/fax on the same physical connection. As a WAN technology, ISDN is typically used for dial-backup support at 56, 64 or 128 Kbps bandwidth.

    Frame Relay
    Frame Relay is a distance insensitive telco charge thereby making it very cost effective. It is used in both private and carrier-provided networks and most recently is being used to carry voice/video/fax/data.

    Switched Multimegabit Data Service (SMDS)
    SMDS provides high-speed, high-performance connections across public data networks. It can also be deployed in Metropolitan Area Networks (MANs). It is typically run at 45 Mbps bandwidth.

    X.25
    X.25 can provide a reliable WAN circuit however does not provide the high bandwidth requirements as a backbone technology.

    WAN ATM
    WAN ATM is used as the high bandwidth backbone for supporting multiservice requirements. The ATM architecture supports multiple QoS classes for differing application requirements delay and loss.

    (Packet over SONET (POS
    POS is an oncoming technology that transports IP packets encapsulated in SONET or SDH frames. POS meets the high bandwidth capabilities of ATM and through vendor implementations supports QoS.

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  9. [69]
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    تاريخ التسجيل: May 2006
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        1. Remote Network Trends
    Branch offices, telecommuters and mobile users constitute remote networks. Some of these may use dial-up solutions with ISDN or analog modems. Others may require dedicated lines allowing access to the WAN 24 hours a day 7 days a week (24x7). A study of the users business requirements will dictate the type of connection for these remote locations. Using ISDN and vendor functionality, a remote location can be serviced with 128 Kbps bandwidth to the WAN only when traffic is destined out of the remote location. Analysis of the ISDN dial-up cost based on up time to the WAN, as compared to the cost of a dedicated line to the WAN, must be determined for each location. This analysis will provide a break-even point on temporary versus dedicated WAN connectivity. Any of the various technologies discussed for the WAN may be well suited for remote network connectivity.
        1. Application availability versus cost effectiveness
    It is the job of the network to connect end users with their applications. If the network is not available then the end users are not working and the company loses money. Application availability is driven by the importance of the application to the business. This factor is then compared against the cost of providing application availability using:
    • Redundant lines for alternate paths
    • Dial-back up connectivity
    • Redundant devices with redundant power supplies for connecting the end users
    • On-site or remote technical support
    • Network management reach into the network for troubleshooting
    • Disaster recovery connectivity of remote locations to the disaster recovery center
    Designing an internetwork therefore has the main objective of providing availability and service balanced with acceptable costs for providing the service. The costs are generally dominated by three elements of supporting a network infrastructure. These are:
    • The number and location of hosts, servers, terminals and other devices accessing the network; the traffic generated by these devices and the service levels required to meet the business needs.
    • The reliability of the network infrastructure and traffic throughput that inherently affect availability and performance thereby placing constraints on meeting the service levels required.
    • The ability of the network equipment to interoperate, the topology of the network, the capacity of the LAN and WAN media and the service required by the packets all affect the cost and availability factor.
    The ultimate goal is to minimize the cost of these elements while at the same time delivering higher availability. The total-cost of ownership (TCO) however is dependent on understanding the application profiles.
        1. Application profile
    Each application that drives a business network has a profile. Some profiles are based on corporate department requirements and others may be a directive for the entire company. A full understanding o the underlying architecture of the application and its use of the network is required for creating an application profile. Three basic components drive a network profile. Figure 3.4 illustrates these graphically. These are:
    • Response time
    • Throughput
    • Reliability
    Response time is a perceived result by the end user and a measured function of the network engineer. From a user standpoint, it is the reduced "think-time" of interactive applications that man dates acceptable response time. However, a network design that improves response time is relative to what the end user has perceived as normal response time. A network engineer will break down the components that make up the response time into the following components: host-time and network time. The difference between the two are that host time is application processing, be this disk access to retrieve data or analysis of data. Network time is the transit time as measured from leaving the host to the network interface of the end user device. Host time is then again computed on the workstation. Typically, host time on a workstation is based on presentation to the end user. Online interactive applications require low response times. These applications are usually referred to as time sensitive applications.

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  10. [70]
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    تاريخ التسجيل: May 2006
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    Applications that rely on the delivery of large amounts of data are termed throughput-intensive applications. Typically, these applications perform file transfers. They require efficient throughput however, many of these applications also depend on the delivery of the data within a time window. This is where they can adversely affect interactive application response times due to their throughput.
    Reliability is often referred to as up time. Applications requiring a high reliability inherently require high accessibility and availability. This intern requires hardware and topology redundancy, not only on the network side but also on the application host or server side. The importance of the function served by the application is weighed by the cost of downtime incurred by the business. The higher the cost-of-downtime the higher the requirement for reliability.
    Creating an application becomes paramount in understanding the needs of a network design. Application profiles are assessed through exercising some or all of the following methods:
    • Profile the user community - Determine corporate versus departmental internetworking requirements by separating common applications from specific applications for each community. If possible, develop the application flow from the end user to the host/server for each common and specific application. Using network management tools gather network traffic profiles to parallel the user community.
    • Interviews, focus groups and surveys - Using these methods insight into current perceptions and planned requirements are discovered. This process is key to developing the current baseline of the network in addition to coalescing information about planned requirements shared by independent departments. Data gathered here in combination with the community profiles is used for developing the new network design.
    • Design Testing - This is the proof-of-concept stage for the resulting design. Using simulated testing methods or real-time lab environments the design is measured against the requirements for response-time, throughput and reliability.
        1. Cost Efficiency
    The network is now an asset to all corporations. As such, investment into the network must be viewed as a total-cost-of-ownership (TCO). These costs are not only equipment investment but also include:
    Total cost of equipment - this includes not only hardware but software, installation costs, maintenance costs and upgrade costs.
    Cost of performance - is the variable against which you measure the improved network performance and reliability against the increase of business conducted. The ratio between the two determines the effectiveness of the investment.
    Installation cost - the physical cabling infrastructure to support the new design becomes a large one-time investment cost. Implement a physical cabling infrastructure that meets current and future networking technologies and requirements.
    Growth costs - Reduce growth costs by implementing technologies today that can meet the direction of technologies tomorrow.
    Administrative and Support - Limit the complexity of the internetwork design. The more complicated the higher the cost for training, administration, management and maintenance.
    Cost of downtime - Analyze the cost of limited, reduced or inaccessible application hosts, servers and databases. A high down time cost may require a redundant design.
    Opportunity costs - Network design proposals should provide a minimum of two designs with a list of pros and cons to each design. Opportunity costs are the costs that may be realized by not choosing a design option. These costs are measured more in a negative way; not moving to a new technology may result in competitive disadvantage, higher productivity costs and poor performance.
    Investment protection - The current network infrastructure is often salvaged due to the large investment in cabling, network equipment, hosts and servers. However, For most networks investment costs are recovered within three years. Understand the cycle of cost recovery at your corporation. Apply this understanding to the design as a corporate advantage in the design proposal.

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