Lesson 1

What is Network Services?

There are many network services available in an organization such as the following:

1. File and Print services - This is a common service in an organization where it separates the network just for file and printing in a local area network.

For most organizations, especially in the early days of PC LANs, fi le and print services were the driving force behind justifying a network. Users need to share information for an organization to thrive. Because of this need, the most common types of network servers are fi le servers and print servers.

File servers make files and directories (fi le folders) available to network users. You can use fi le servers to share programs and fi les that users need to access, like templates and reference files. You can use them to store files for a project or design team. One of the primary reasons for having file servers is to give the users a central location for storing their own fi les and to ensure that the fi les are backed up regularly. The unfortunate truth is that files stored on a user’s own local computer are seldom, if ever, backed up.

2. Application Server Service - present only if the organization has its own local or online applications.

Server applications are usually deployed on an as-needed basis. The most common server applications are relational database applications and web servers. Web servers can host websites (for public access or for internal use) and web services, which are applications that are accessible from the Internet or local intranet. Web services accept parameters and return values formatted using Extensible Markup Language (XML), a format used for formatting data for transfer. It has become a standard for data transfers across the Internet. You may see other server applications, such as e-mail servers, servers designed to support group projects and other shared documents, or even team development servers that facilitate team-based software development.

Servers that support public access are sometimes deployed outside of the LAN on an isolated perimeter network known as a Demilitarized Zone (DMZ), as shown in Figure 8-2. A firewall, a network security device that filters network traffic, isolates the perimeter network from the rest of the LAN, acting like a gatekeeper that keeps the outside world out, but allows limited interaction with servers deployed on the network. A host-based firewall is a firewall running on a single host or server. These firewalls restrict network traffic for only that server.

DMZ- https://www.youtube.com/watch?v=dqlzQXo1wqo

Firewall - https://www.youtube.com/watch?v=kDEX1HXybrU

3. Network Support Service - used to keep the network running smoothly.

Some support services are required. Others are optional, depending on your network configuration. This area is where servers might be called on to perform multiple duties, depending on the specific services they are hosting. Servers that support network services include servers such as:

• Network control and management servers, which run the NOS, handle the control functions for the network, authenticate users, and take care of network background management tasks. https://www.youtube.com/watch?v=feHpDc1cLXM

• Specialty authentication and authorization servers, such as Remote Access Dial In User Service (RADIUS) servers.

• Remote Access Servers (RAS, or Microsoft Routing and Remote Access Servers {RRAS}, Virtual Private Network (VPN) endpoints, and software configured routers.

https://www.youtube.com/watch?v=-E1GvdJCoX0

• Network protocol support servers, such as Domain Name System (DNS) and Dynamic Host Configuration Protocol (DHCP) servers.

DHCP -https://www.youtube.com/watch?v=e6-TaH5bkjo

DNS- https://www.youtube.com/watch?v=mpQZVYPuDGU&t=18s

• Servers providing shared or public resources.

• Network Address Translation (NAT) and Internet connection sharing servers.

https://www.youtube.com/watch?v=FTUV0t6JaDA

• Specialized gateway devices, such as mainframe computer gateways for mainframe access.

This list is by no means complete for all of the types of servers you might see. As with application servers, the types of servers you have will depend on your network’s specific requirements. For example, if you don’t have any remote access requirements, you won’t have a remote access server

Note:

Implementation of network services may vary on implementation by using different Network Operating System (NOS)