What is NAT ?

 NAT stands for Network Address Translation. This technique allows a single global IP address to be shared by many computers on a single local area network.

What is an edge router ?

 An edge router, which provides a connection between a local network and Internet. Equivalent to "gateway".

What is meant by packet in computer networking?

 A packet is limited-size fragment of a large message. Large messages or files are split into many packets and sent across the Internet. The typical maximum packet size is between 1000 and 3000 characters.

Explain hop in computer networking

 Hop is  a single physical network connection. A packet on the Internet will typically make several "hops" to get from its source computer to its destination.

Network Printer Trouble Shooting Tips

I can't connect to the network printer, while clicking print, system shows some error messages, what I want to do?

Try following Trouble shooting methods

• Check the network printer connection. Check the connection cable
• Check the printer is working properly, if it shows error messages trouble shoot it first
• if the printer is OK, try to connect the printer using the ping command. To do this Start menu-> command prompt Type  ping IPADDRESS OF PRINTER   (to do this you need to know ip address of the printer - check it in printer settings )
• if the printer is connecting ping will shows replay messages
• Restart the system. This will solve most of the printer problems
• check the printer settings and paper orientation settings (in old type printers).
• Restart print spooler services from windows services (to do this type services in search bar of windows start screen and press OK. Check spooler service, right click it and restart it.)

I think following steps will help..

Please comment

 

Basic Network Problems

Following are the basic network issues that happens in a computer network
1. Network or router connection issue card not connected properly.
2. Bad network card drivers or software settings.
3. Firewall preventing computers from seeing each other.
4. Connection related issues.
5. Bad network hardware.

Define APIPA, IP address and Subnet mask

APIPA: Automatic Private IP Addressing
It is a feature of Windows that if client cannot connect DHCP server to get IP address, it get a default IP address with in the range of 169.254.0.1 - 169.254.255.254.
IP Address: IP address is a numerical identifier assigned to each machine on ip network. It is a software address.
Subnet mask: subnet mask is used to identify in which class the IP address belongs to.

How many bits in MAC Address?

A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.

MAC address is 48 bit long. It is in Hex (6 group - 2 Hexadecimal number in each).

Examples of MAC address 

1.  48-2C-6A-1E-59-3D

2.  12-34-56-78-9A-BC

What are the OSI layers?

OSI(Open System Interconnection) is a Standard reference model for communication between two end user network. It is used in developing products and understanding networks.
The Seven OSI layers 
1. Application Layer
2. Presentation Layer
3. Session Layer
4. Transport Layer
5. Network Layer
6. Data Link Layer
7. Physical Layer

What is the difference between Network operating System and Server Operating System?

NOS- Network Operating System
Network Operating System refers to software that implements an operating system of some kind that is oriented to computer networking. For example, one that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions.The network operating system is designed to allow shared file and printer access among multiple computers in a network, typically a local area network (LAN), a private network or to other networks.

Network Operating Systems can be embedded in a router or hardware firewall that operates the functions in the network layer (layer 3) of the OSI model.

Examples of Networking Operating Systems:

1. JUNOS, used in routers and switches from Juniper Networks,
2. Cisco IOS (formerly "Cisco Internetwork Operating System").
3. TiMOS, used in routers from Alcatel-Lucent
4. VRP (Versatile Routing Platform), used in routers from Huawei
5. RouterOS, software which turns a PC or MikroTik hardware into a dedicated router
6. ZyNOS, used in network devices made by ZyXEL.
7. ExtremeXOS, used in network devices made by Extreme Networks. Also called EXOS.

SOS- Server Operating System

A server operating system is software that was especially developed to serve as a platform for running multi-user computer programs, applications that are networked and programs critical to business computing. This type of operating system (OS) often comes bundled with the most common types of applications deployed in the client-server model, a term used to indicate the exchange of information between computers. For example, a hypertext transfer protocol (HTTP) or web server hosts or "holds" the text files, images files and scripts that work together to form a website. When someone connects to the Internet and types in a web address, the server that holds the files of the site delivers or "serves" the requested pages to the client computer or the machine that made the request.

Examples of Server operating Systems

1.Windows server versions
2.Red hat/Linux server

What is a port no ?

A port no is the part of addressing information used to identify senders and receivers of message. It is used with TCP/IP connection. Each port number allows different application.

                                          Table :Port Number Assignment

What is the Role of a Server in a network ?

Server is the computer that facilitates the sharing of data, software and hardware resources such as printers, modems etc. On a network there may be several servers that allow work stations to share specific resources such as file server for serving files related requests, printer server to take care of printing requirements and modem server to help a group of network user to use modems. Each server has a unique name on the network and all users of network identify the server by its unique name.

What is a Computer Network ?

 What Is a computer Network?

1) A Computer Network is defined as a collection of Autonomous computers interconnected by a   single technology.Interconnection means they are able to exchange information among themselves.

2) A Network is the interconnection of computers located at different places.It is both software and hardware.


Related post:
Computer Networking Basics PDF E-book

TOP SIX COMPUTER NETWORKING CERTIFICATION AREAS TO BECOME A NETWORKING EXPERT

  To become a networking Specialist you should learned the following areas
                    

 1. Hardware & Desktop

 With knowledge of hardware-both computer & peripherals, helps you apply the role of trouble shooter who studies the fault with the hardware & recommends tasks for rectifying the error. You are called a "Hardware Engineer", in this profile. You could also play the role of administering desktops in office environment, where emailing, printing  application management etc are a second-by-second activity. A "Desktop Administrator" must have thorough knowledge of how basic connectivity & desktop operating systems work. Microsoft's windows is the most popular operating system in this space, followed by open source desktop operating systems like Red Hat, Ubuntu etc.

2. Networking

       Well every trained candidates dream job is in this segment - "networking".so what can you do? You can do basic networking job -  like ensuring that all your desktop are in the network. You can also ensure that you manage the network operating systems like windows, Unix or Linux based systems installed to run the network. These could be typically Microsoft, Red Hat, Sun , IBM or HP systems. You could also manage the network infrastructure like routers, switches etc. which are typically Cisco & Huawei etc.

3. Security

 Every organization's concern area is security. Information security administrator means protector of information and information systems from unauthorized access, use, disclosure, disruption, modification, perusal, inspection, recording or destruction. Information security is concerned with the confidentiality, integrity and availability of data regardless of the form the data may take: electronic, print, or forms. The field of information security has grown and evolved significantly in recent years. There are many ways of gaining entry into the field as a career. It offers many areas for specialization including: securing network(s) and allied infrastructure, securing applications and databases, security testing, information systems auditing & business continuity planning.

4. Cloud

Cloud computing refers to the availability of IT resources on demand via a network. Cloud computing offers computer application developers and users an abstract view of services that simplifies and ignores much of details and inner workings. A provider's offering of abstracted Internet services is often called "The Cloud". The "cloud" technology is based on Virtualization. This is the creation of a virtual (rather than actual) version of something, such as a hardware platform, operating system  a storage device or network resources. Virtualization can be viewed as part of an overall trend in enterprise IT that includes autonomic computing, a scenario in which the IT environment will be able to manage itself based on perceived activity, and utility computing, in which computer processing power is seen as utility that clients can pay for only as needed. The usual goal of virtualization is to centralize administrative tasks while improving scalabilty and work loads.

5. Virtualizaiton

 Virtualiztion, in computing, is the creation of a virtual (rather than actual) version of something, such as a     hardware platform, operating system, a storage device or network resources.

6.Ethical Hacking

 An Ethical Hacker is an expert hired by a company to attempt to attack their network and computer system the same way a hacker would . Ethical Hackers use the same techniques and tactics as those used by illegal hackers to breach corporate security systems. The end result is the company's ability to prevent an intrusion before it ever occurs.