Basic of Networking

Classification of Computer Network:

LAN (Local Area Network) is a network of computers that are connected to a computer server by using specific topologies, typically used in building area or distance that is no more than 1 km.

MAN (Metropolitan Area Network) is a network of

computers that are connected in one area of town distanced more than 1 km. The option to build a computer network are a city office, a campus in the city.

WAN (Wide Area Network) is a computer network connecting many LAN into an integrated network; from one network to another network distanced about thousands of kilometers or separated geography location by using a specific communication method.

In the main idea, there are several stages in building a LAN network, such as;

•    Determining the type of network technology (Ethernet, Fast Ethernet, Token Ring, FDDI)

•    Choosing a model cabling (Fiber, UTP, Coaxial)

•    Determining the type of the network topology (bus, ring, and Star)

•    Determining Client technology / Server or Peer to Peer

•    Choosing the Server Operating Systems (Windows NT, 2000, XP, or Linux)

About Gateway

Gateway is the gateway as the incoming and outgoing data packets from the local network to the outer network. The goal is to make the client on the local network be able to communicate with the internet. The router can also be configured into Gateway where it will be a liaison between the local network to the outside network.

Description of Proxy Server

Proxy Server is a facility to connect to the internet simultaneously. It provides the users’ demand for Internet services (HTTP, FTP, Telnet) and submit it in accordance with the policy. It acts as a gateway to the services. It represents the data packets from the inside and from the outside. It handles all Internet communications - external. It acts as a gateway between the internal and external machines. The proxy server evaluates and controls the request of the client, if it is appropriate according to the policy, then it may pass but if it is not, then it will be denied / dropped. It uses NAT method. It checks the package contents.

Definition of Firewalls

A firewall is a security system that uses a device or system that is placed in the network with two main functions as it performs filtering on the access entry. A firewall can be a set of hardware or software. It can be a set of rules and procedures established by the organization. Firewall can be called as a system or device that allows network traffic that allow safe traffic to pass through the network and prevent the unsafe one. Generally, firewalls which run on the gateway (gateway) between the local network and other networks that are implemented in a dedicated machine. Firewalls are also commonly used to control access to anyone who has access to a private network from the outsider. Today, the firewall term is a generic term that refers to a system that manages the communication between two different networks.

Description of Virtual LANs

Virtual LAN (VLAN) is a software from switch device that serves to categorize the user based on functional, 1 broadcast domain (VLAN 1) and inter-VLAN can be connected to the router.

VLAN technology is a way of separating the segments in the switch in which between one segment to another segment cannot be connected; the connection can be done by using a router. In one switch, the network-id and broadcast domain will be different