Network Services: Deployment and Maintenance

• The study notes cover deployment and maintenance of network services, focusing on shared resources, TCP/IP infrastructure services, intranet/internet, and network storage systems.

Shared Network Resources

• Local area networks are characterized by the services they provide to users.
• Some services are transparent but essential for network organization.
• A network resource performs actions upon request and becomes shared when the request is serviced over a network.
• Resources are physically located on specific network nodes but are virtualized when shared, allowing transparent access from any node.

Disk Management

• Shared disks, folders, and files are the most commonly shared resources in local networks.
• Appropriate disk selection positively influences system speed and security.
• Servers benefit from fast interfaces like SCSI (Ultra/Wide SCSI), while workstations can use IDE, Serial ATA, or similar interfaces.
• To access a shared hard drive, specify \\SERVER-NAME\RESOURCENAME.
• If the sharing computer has an IP of 192.168.5.7 and the resource name is DISCODURO, the access path is \\192.168.5.7\DISCODURO.

Document Printing Resources

• Networks facilitate the sharing of printing devices as not all users have local printers.
• Local area networks allow clients to connect to network printers with appropriate access rights, even printers from different manufacturers' networks.
• Dedicated print servers manage printing tasks based on parameters like speed, quality, privileges, priorities, and costs.
• Internet Printing Protocol (IPP) allows web-technology-based transmission of print files to compatible printers using HTTP.
• IPP is OS-agnostic, working equally on Windows and Linux.
• Windows allows specifying user/group permissions for printer usage: Print, Manage Printers, and Manage Documents.
• Linux offers permission to print or deny printing, which is less granular than Windows.
• To access a shared printer, indicate \\SERVER-NAME\PRINTERNAME.
• For a computer with IP 192.168.5.7 sharing a printer named IMPRESORA, the access path is \\192.168.5.7\IMPRESORA.

TCP/IP Infrastructure Services

DNS Services

• DNS (Domain Name System) organizes TCP/IP node names hierarchically on the internet to facilitate memorization, which is easier than remembering IP addresses.
• Each DNS name has two parts: the first identifies the node within a subnetwork, and the second identifies the subnetwork itself, called the domain.
• Internet node proliferation necessitated domain fractionation into subdomains of one or more levels.
• In a complex TCP/IP network, each node must have the IP addresses of DNS servers to resolve network names.
• While only one DNS server is strictly necessary, security reasons often lead to assigning two or more, with the first being termed the primary DNS.
• DDNS (Dynamic DNS) allows nodes to automatically register their names and link them to their IP addresses on a DNS server.
• Windows servers include DNS server software without requiring an additional license.
• The predominant free software DNS server for Linux is bind9, which is powerful and flexible even without a user-friendly graphical interface.
• DNS intends to hierarchically organize the names of all nodes connected to the internet
• When a computer needs to communicate, it can access by IP address or DNS name; the DNS server translates the name into an IP address.
• DNS names consist many parts, the far right is the top-level domain (.com), labels to the left specify the subdomain (google), and the leftmost label is the node (www).

WINS Name Servers

• Windows Internet Name Service (WINS) resolves and registers computer names, assigning NetBIOS names to IP addresses.
• WINS implementation lets users access network resources by name instead of hard-to-remember IP addresses.
• Software and services on devices can send name requests to the WINS server to resolve names into IP addresses.
• Node registration in the WINS database is automatic upon registering its NetBIOS name.
• Windows integrates WINS with DNS, establishing correspondence between both name resolution systems.
• The command ipconfig/all verifies WINS is enabled on a computer
• To enable the server you must, select "Start" > "Configuration" > "Network and Sharing Center", then click on your wifi connection. Then, select "Command Prompt"> Run as administrator > Type the command "nbtstat -RR > Restart".

DHCP Services

• DHCP (Dynamic Host Configuration Protocol) helps automate IP address assignments to hosts.
• A DHCP server assigns an IP address to each requesting network node, preventing duplicate assignments within the same network.
• If a node's IP changes or it shuts down, its address is released, allowing the DHCP server to assign it to another requesting node after the reservation time ends.
• Modern DHCP servers assign parameters like routers, DNS servers, WINS servers, mail servers, masks, and time servers, plus they also allow IP address reservations.
• Only one DHCP server can exist in each network segment.

Intranet and Internet

Web Technology Globalization

• Corporations use internet technology in their local area networks, turning LANs into intranets.
• Technologies like HTML, XML, XHTML, PHP, JavaScript, Python, ASP, Java, and .Net Framework create complex web applications that facilitate interoperability and flexibility across software and hardware platforms.

Intranet Requirements

• A local area network should run the TCP/IP protocol to facilitate LAN access to servers and to install network name resolution systems (DNS).
• All computers need the TCP/IP protocol and a web browser for intranet access.
• Intranet servers provide services like web and FTP within the local area network.
• System configuration must include a document location design, a hierarchical structure in page form for navigation, and access permissions for each user.

Personal and Relational Communication Services

• Collaborative tools or groupware are interesting applications that can be established in corporate networks
• Fundamentally, these applications consist of the equipment of the participant in a project. The most basic groupware tool is email.

Mail Servers

• The Simple Mail Transfer Protocol (SMTP) is the most commonly used protocol for internet mail service.
• SMTP messages are limited to 7-bit ASCII characters, excluding accented or special ones.
• SMTP has limited binary file transfer.
• The coding UUENCODE, which allows you to solve these problems, was incorporated into SMTP . The listen port is usually 25.
• MIME (Multipurpose Internet Mail Extension) allows to include any binary information: voice, video, image, etc.
• SMTP transfers email between servers and moves messages from clients to servers.
• Protocols like POP and IMAP are needed to download received emails, and help client applications.

Mail Protocols

• POP (Post Office Protocol) downloads files to the local client, enabling offline mail access, and deletes mails upon download
• IMAP (Internet Message Access Protocol) works directly on the server, allowing access from another client on any device.
• Email access is commonly done through an internet browser via its URL
• Protocols similar to those above are used more and more frequently but with secure, encrypted connections such as SMTPS and IMAPS.

Network Storage Systems

• The services of network storage allows not only to share information, but also to have greater storage capacity.
• The volume of data accessed through a network is immense. This bottlenecks the network so much that the architectures of the network must be changed to meet demanding specifications.
• The storage technology consists of several solutions that correspond to as many architectures.

DAS (Direct Attached Storage)

• Each network station has its disks and serves them to the network through its network interface.
• It is not designed to share information over the network, and is focused for small businesses that share data locally.

Centralized Storage

• Several servers or stations can share physically linked disks.

NAS (Network Attached Storage)

• Disks connect to the network, and stations or servers use the network to access them.
• They are designed to share information across the network
• Data can be accessed locally and remotely.
• Servers are on the same network as clients and are available 24/7.
• NAS is intended for small and medium-sized companies and organizations.
• Protocols used for access are NFS and SMB.

SAN (Storage Area Network)

• It is a network for storing fast speed and high bandwidth, created to alleviate issues with the growth of servers and data.

• SAN has an architecture that separates two networks

• Tradional area network

• Data access network

• With this apporoach servers can access storage through a specialized nework and clients can access that data through the servers.

• Fibre channel or iSCSI technologies are used for fast access to many disks

• SAN are focused on large companies and organizations.

Explore the essentials of deploying and maintaining network services, covering shared resources and TCP/IP infrastructure. Learn about managing network storage systems and intranet/internet functionalities. Understand how resources are virtualized for transparent access across network nodes.