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What are the main network architecture models?
- Three main models:
- –Peer-to-peer (P2P)
- –Client/server (C/S)
- –Directory services
- Hybrid model
- –Combines peer-to-peer & client/server
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List the common server types.
- Files server
- Print server
- Messaging server
- Application server
- Web server
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Describe files servers
–File servers offer users a central location to save files.
–The security control access to these files depends on the network architecture and server type.
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Describe print servers
–The print servers stores the print jobs in a print queue until a printer is available.
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Describe Messaging servers
–Manage and route email messages.
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Describe Application servers
- –Database servers–Business
- -specific applications
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Describe Web servers
- –Virtual hosting
- One system is able to serve as a host for multiple domain names, allowing several systems to share a single IP address and the host system to share resources (e.g., memory, processor cycles, etc.).
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Describe Peer-to-peer networking:
- –Is a design where any computer can act as both server and client
- –decentralized resource sharing (files and printers)
- –Usually inexpensive
- –Typically smaller organizations(–Best suited for fewer than 12 users, Some suggest up to 20 users)
- -files are not stored in a central location
- –Allows computers (and users) to communicate easily
- -uses Workgroups
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Describe Workgroups
–Logical peer-to-peer grouping
–Term used most commonly to describe a peer-to-peer network.
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Advantages of peer-to-peer networks:
- –Are easy to configure
- –Integrate networking software in the operating system
- –Typically do not require additional server hardware and software
- –Allow users to manage their own resources
- –Do not require a network administrator
- –Reduce total cost in comparison with other network architectures
- However, this doesn’t account for hidden costs
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Disadvantages of peer-to-peer networks:
- –Provide limited number of connections for share resources
- –Computers with shared resources may suffer performance issues
- –Do not allow for central management
- –No central file storage
- –Require users to be responsible for managing resources
- –Offer poor security
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What are things to consider when choosing a P2P network
- Budgetary constraints
- -Peer-to-peer networks are uniquely suited to situations with budgetary constraints
- Level of computer literacy
- -Users will be expected to handle their own resource sharing
- Total cost ownership
- -Hardware costs, management costs, hidden costs, etc
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Describe main characteristics of Client/Server Networks.
- A centralized model for:
- -data storage
- -Allow a high level of security based on permissions.
- -network applications
- -Managed centrally by network administrator(s)
- Also called server-based networks
Yield cost savings by centralizing resources, data and security
- Offer performance improvement over peer-to-peer networks
- -Client and server can process information simultaneously
- -Provide shared services
- -Employ specialized servers that provide services to the client workstations.
- -scalable
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Client/Server Networks Advantages:
- Data are stored centrally and can be easily backed up.
- User accounts and security are centrally managed.
- A high level of security can be implemented at the server(s).
- Resources can be shared with multiple users.
- Server hardware and software are optimized for performance and reliability.
- Users are relieved of the burden of managing resources.
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Client/Server Networks Disadvantages:
- Planning, design, and management are more complicated.
- Managing servers requires dedicated staff.
- Server software and hardware can be expensive.
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GPO
Client/Server Network Security Typically allow creation of groups of users that are assigned same access permissions(GPO – Group Policy Objects)
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A Single-Server Network
- Used when a company outgrows its peer-to-peer network
- Server is responsible for:
- -Processing user logins
- -Handling user security
- -Acting as a file and print server
- If the server fails, so does the network
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A Multiserver Network
- Client/server networks based on multiple servers
- -More complex than a single-server network
- Provides better user support
- -Services are spread across multiple servers to improve performance and reliability
- -If one server fails, other servers continue to function normally or take over the malfunctioning server
- -Virtualization
- -Cloud based
- Model can be expanded by connecting individual LANs
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Microsoft’s directory-based network architecture is called
Active Directory/Domain Services
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Domain members:
users and computers located anywhere assigned to a domain
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Domain controller:
Responsible for maintaining the directory of network objects and managing user authentication and authorization.
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Member server
: any server that is part of the domain except those that manage the directory and security functions
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Directory Services Network Characteristics:
- Based on a model that scales.
- Domain controllers process user authentication and authorization.
- Domain centralizes security and resource management.
- Provide flexible security for shared resources.
- Provide a high level of security with detailed control.
- Are centrally managed.
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Directory Services Networks Advantages:
- Greater flexibility
- Enhanced management capabilities
- Enhanced security
- Manufacturers are phasing out support for more traditional client/server networking models
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Directory Services Networks DisAdvantages:
- Administrators must have proper education
- Number of management/design options can be confusing
- One domain controller must run at all times
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Hybrid network architectures
- A network architecture that makes use of a combination of other types of architectures.
- incorporate the best features of workgroups in peer-to-peer networks with the performance, security, and reliability of server- or directory-based networks.
- allow different standard network architectures to coexist on same network.
- provide centralized services of servers.
- allow users to share and manage own resources.
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Hybrid Architectures Advantages:
- Server applications are centrally located and managed.
- Users can assign local access to resources on their computers.
- Users can manage resources without requiring assistance from the network administrator.
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Hybrid Architectures Disadvantages
- Network access can be burdensome for users.
- Users may need to remember multiple passwords.
- Files can be duplicated and changes can be overwritten.
- Files saved on the workstation are not backed up.
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