IP Addressing

IP address is a unique identifier of a computer on TCP/IP networks and on the internet. Every computer requires a unique IP address to be a part of the internet and the IP address is provided by the internet service providers. Every IP address consists of the 32 bits and a binary system of 0s and 1s. The binary number system consist of only two types of digits 0 and 1. It is easier for us to remember the decimal numbers rather than the binary number system such as 011001101. On a same network segment, all the IP address share the same network address. There are five classes of the IP addresses such as A, B, C, D and E and only 3 classes are in the use. Class D IP addresses are reserved for the multicast group ant cannot be assigned to hosts and the E class IP addresses are the experimental addresses and cannot be assigned to the people. Every IP address consists of 4 octets and 32 bits. Every participating host and the devices on a network such as servers, routers, switches, DNS, DHCP, gateway, web server, internet fax server and printer have their own unique addresses within the scope of the network. TCP/IP protocols are installed by default with the Windows based operating systems. After the TCP/IP protocols are successfully installed you need to configure them through the Properties Tab of the Local Area Connection. IP Addresses Classes Class A The binary address for the class A starts with 0. The range of the IP addresses in the class A is between 1 to 126 and the default subnet mask of the class A is 255.0.0.0. Class A supports 16 million hosts on each of 125 networks. An example of the class A is 10.10.1.1. Class A is used for the large networks with many network devices. Class B The binary address for the class B starts with 10. The range of the IP address in the class B is between 128 to 191 and the default subnet mast for the class B is 255.255.0.0. Class B supports 65,000 on each of 16,000 networks. An example of the class B address is 150.10.10.10. Class B addresses scheme is used for the medium sized networks. Class C The binary address for the class C starts with 110. The range of the IP addresses in the class C is between 192 to 223 and the default subnet mask for the class C is 255.255.255. Class C hosts 254 hosts on each of 2 million networks. An example of the Class C IP address is 210.100.100.50. Class C is used for the small networks with less then 256 devices and nodes in a network. Class D The binary addresses for the class D starts with 1110 and the IP addresses range can be between 224 to 239. An example of the class D IP address is 230.50.100.1 Class E The binary address can starts with 1111 and the decimal can be anywhere from 240 to 255. An example of the class E IP address is 245.101.10.10 It is very important to know that all the computers in the same network segment should have the IP addresses for the same class i.e. form A, B or C. IP Addressing Tips A Network ID cannot be All 0s A host ID cannot be All 1 because this represents a broadcast address for the local network. Each host must have a unique host portion of the IP address. All hosts on the same network segment should have the same network id. A host address cannot be 127 because 127 has been reserved for the loop back functionalities.

Computer Networking

Computer networking is a linking of the network devices and computers with each other to provide the data communications and sharing the network resources such as printer, scanner, modem, CD/DVD and internet access. A computer network can be interconnected with the UTP/STP cables, coaxial cables, fiber optics and wirelessly through the radio waves. Today, no business can work effectively without the data communications within the organization. A network can be designed by different layouts known as topologies. The common topologies include star, hub, mesh, hybrid and ring. Star topology is the most common topology in Ethernet based local area network. There are specialized rules and standards and based on these standards, the devices communicate with each other. One of these specialized standards and agree up ways is known as protocols. TCP/IP is the protocol suite that contains the multiple communication protocols such as TCP, IP, SMTP, FTP, DHCP, LDAP, PPP, Telnet and many others. TCP/IP works together and it is the most common communication protocol for the LAN, WAN and internet. The communications on the internet is based on the IP addresses, which is a part of the TCP/IP stack. No computer on the internet or in the LAN/MAN/WAN can communicate without a unique IP address. Networking and data communications provides the flexibility, easy of work and communications with each other and today every kind of business in the world, which involves more than one computer, require a computer network. A network can be setup by using the following things. Computer with Windows/Linux operating system installed. Every computer requires a unique LAN card, which should be properly installed and configured. Ethernet cable with the RJ-45 connectors at both ends. A Router/Switch or hub. The other devices are bridges, transceivers, terminal servers and gateways and they can be setup according to your requirements. There are three main types of the computer network i.e. LAN, MAN, WAN, CAN, GAN and PAN and each network either be a peer to peer or client server network. In a client/server network model, a centralized domain controller is used to control all the computer network. It provides the services to the clients like logon authentication, printer access, scanner access, centralized data storage, user management, resources management, DHCP, DNS, FTP and internet access. To communicate with the other computer, each computer should support the same protocol and the TCP/IP is the most commonly used protocol in a computer network. Internetwork is a type of computer network that connects the two or more different networks. There are three main types of the internetwork i.e. intranet, extranet and internet.

Network Security

Security is an important ingredient for computer network (LAN, WAN, MAN) maintenance. It is the job of the network administrator to save your online presence from malicious attacks of hackers, viruses, and Trojans through a reliable security system. Whether you are working in a home or enterprise network, try to secure it by implementing advanced and protective security strategies. Network security is the study of implementing different techniques to save your business and home computers from malicious hacking and virus’s attacks. Here is a brief overview of some common network attacks. Denial of services Denial of service strategy is applied to a specific web server so that it becomes unavailable for internet users. Hackers usually send too many requests for general information. In this respect, it makes use of web server resources that can either slow down or crash the server. BlackHat Hacking Network hackers with technical knowledge can easily access any unsecured network. Common network damage involves configuration change in network equipment like router servers. They usually make these devices unavailable for internet users. Consequently such types of problems take network administrators a great deal of time and effort to fix the problems. It results in a loss of money because productivity is reduced drastically. Some hackers even get access to private information like patient/client record, or credit card details. These damages can cost thousands of dollars to your company. At home, these network hackers try to steal your sensitive information like credit cards and other scanned documents. Here, I would like to suggest some essential network security principles that every computer user must install on their network servers and systems. Firewall It is called a set of principles to deny or allow access to the network. It is usually installed inside the network router. The basic purpose of using a router is to get access to the network. Firewall works on a set of rules based on closing and opening of ports associated to protocol. Whenever any internet user stops using a network protocol for communication, the router closes the port of this protocol. Access Control Lists Access control list works like a firewall. Its basic function is to filter network traffic based on various metrics included in IP packets. Access control list is configured to test the secure status of each packet (data segmentation on OSI layers) and IP address destination. It also checks the destination and source port number. Usually, a network administrator writes an access control list and specifies the range of IP addresses communicating to each other and the protocols used in this communication session. In such situations, it becomes quite tough for network hackers to get access to a network in which the router is blocking unauthorized access. Encryption It is an easy and simple algorithm used to convert information into an unreadable format. Only a person who has access to the specific algorithm can decrypt it. Always try to send sensitive information through these encryption techniques. WEP / WPA These days, wireless networks are widely used due to their portability features. It is also necessary to protect your wireless network from hackers. Recent research indicates that a new version of wireless network called WPA2 is more secure than its previous version (WEP). When you are setting your wireless network, you must set your security to WPA2.

Networking Notes

I would like to discuss some basic networking notes especially helpful for beginners who are thinking of establish a good career in this field. These networking notes supply the fundamental details about network types, communication technology, network troubleshooting, network topologies, network products and also the fundamental summary of the WAN and LAN models of communication. What is computer network? Internet is simply a type of network. When several devices are attached to one another, generally we are able to refer to it as a network. If these devices are computer systems, we'll refer to it as a computer network. What's DHCP? DHCP means Dynamic Host Configuration Protocol. It is used to assign the computer IP addresses and also for other types of network configurations like DNS. DHCP cuts down the administrative tasks of manually assigning IPs to computer systems inside a network. What's DNS and just how it really works? DNS means Domain name system that translates host names into the network IPs and IP addresses into host names. Every computer and also domains on the web have designated distinctive IP addresses. Internet communication is dependent on these IP addresses. These addresses have been created in the format of 10.1.1.200, 192.168.2.0 etc. It is difficult to remember these IP addresses; however host names are simpler to remember than their IPs. What is computer Firewall? It is a protective boundary for any network. It prevents the access of unauthorized sources over the network. The majority of Microsoft operating-systems, for example Windows XP service pack2, have generated-in firewall utilities. Types of networks Essentially, you will find three kinds of computer networks: local area network (LAN), (Metropolitan Area Network (MAN) and Wide Area Network (WAN). The communication inside a WAN is dependent on Hubs. A WAN network covers a town, country or regions. LAN is the interconnection of different hubs, routers and other networking devices in a specific place joined with a cabling system. MAN network covers the range of a limited metropolitan area. Voice over internet protocol (VOIP) Communication Technology Voice over internet protocol means VoIP. This technology can be used for voice data transmission over a specific IP based on the long distance of a network to create telephone calls. Voice over internet protocol telephone calls is fairly inexpensive and many organizations, offices and home customers are utilizing Voice over internet protocol technology to make long distance telephone calls. Wi Max Technology It is basically a wireless broadband technology that is an advanced form of Wi Fi. Wi Max technology supports data, audio and video communication simultaneously at a good speed of 70 Megabyte per second. Network Gateway It can be hardware or software. A gateway is generally a joining reason within a network. It connects normally two systems. Computers connected by using two LAN cards act as a gateway. Router It routes visitors to its destination in line with the source and destination IP addresses that are put into the routing software that is referred to as a routing table. Fiber Optic Cable Fiber optics offers the quickest medium of communication for data, voice and video transfer. Data travels at the speed of light in these cables. Internet service providers and other corporate offices are often connected with one another using this fiber optic cable to supply high-speed connectivity. What's File Server? It is a computer inside a network that provides authentication to network consumers of networks like Home Window 2003 Servers. OSI Model of seven layers The fundamental reason for the seven layers OSI model is to comprehend the data transmission and communication system steps. These layers are Application layer, Presentation layer, Transport layer, Network layer, Data Link layer and Physical layer. Each layer has its own functionality for data transmission from source to destination. GSM Technology It is wireless short range technology. This technology is usually utilized in cell phones, portable products, audio players, Laptops, computer systems as well as in vehicles.

Microsoft Certifications

Microsoft certification is helpful to validate the expertise and skills individuals use in their daily routine. It enhances your problem solving expertise and your skills on the job. It is recommended for every IT professional to earn Microsoft's certifications because it will improve their resume ratings and demonstrate their expertise in the IT sector. So, go forward, strive for the respect, reward and recognition you want and become an excellent certified professional! Microsoft certifications For IT professionals Microsoft certified technology specialist (MCTS): It is the basic certification for professionals with one-year experience in IT support. It is available in technologies like BizTalk server, system center and Microsoft exchange server. Microsoft Certified IT Professional (MCITP): It enhances the IT professional’s abilities and skills in a specific area such as network administration or database. It requires a minimum of two years experience in the IT sector. Microsoft Certified Systems Administrator (MCSA): It is for such individuals who have experience in managing Microsoft server 2003. It is suitable for every professional with 1 to 12 months experience in Microsoft server systems. Microsoft Certified Systems Engineer (MCSE): It verifies a professional’s ability to install and design network systems. This type of certification is useful for experienced specialists like system engineers. For Developers Microsoft Certified Professional Developer (MCPD): It is designed for developers working in visual studio and .net framework. Usually, professionals having two years experience in development can get this certification. Microsoft Certified Applications Developer (MCAD): It is suitable for software developers who have experience in desktop application, software programming and database services based on Microsoft operating systems. Professionals with two years experience in application development can apply for this certification. Microsoft Certified Solutions Developer (MCSD): It aims at developers with expertise in programming and business solutions. Candidates must be proficient in .net framework 1.1 and 1.0 technologies. It is an advanced type of certification and requires two years experience at the enterprise level. Advanced Microsoft Certifications MCM (Microsoft Certified Manager): It is easy for professionals to earn the designation of ‘master’ by taking this course. First students need to finish the training program offered by Microsoft, and then they can take a certification exam. Microsoft Certified Architect: Professionals who have a Microsoft designation are eligible for this course. It is suitable for individuals who have 10 years or more experience in the IT field. General Office and home user certifications MOS (Microsoft Office Specialist): This certification is recognized globally for demonstrating business skills at an advanced level using Microsoft office 2010. In addition, it is helpful in using Microsoft office 2007, windows vista, XP and other skills related to Microsoft desktop applications. Trainer MCLC (Microsoft Certified Leaning Consultant): It is a recognized certification for MCT professionals who have to perform job roles like engaging with IT customers and support. These experts help people in delivering and designing customized solutions. MCT (Microsoft Certified Trainer): It helps people to demonstrate their IT skills. It encourages them to provide training course details to developers and IT professionals. Other Microsoft Certifications are: • Microsoft Technology Associate • Microsoft certified desktop support technician (MCDST) • Microsoft Dynamics Certifications