Internet can be defined as the worldwide network where machines like computers, servers, and smart devices are connected together for communication and data exchange purposes. In the layman's terminology, the Internet is the network of networks interconnecting computing devices located throughout the world. These networks use some communication protocols to link the network devices with each other.

A Wi-Fi (also known as WiFi) is a wireless network technology which allows WiFi enabled devices to communicate with each other, and also share the Internet without wired connectivity. Wi-Fi is based on 802.11 IEEE network standard which uses radio frequency signals to transmit data. The distance supported by Wi-Fi network depends on the type of Wi-Fi radio and antenna in use, and whether the environment is open or enclosed within walls and bricks. As the distance between the Wireless Access Point (WAP) and mobile device move farther away, the radio signal weakens and the transmission data rate slows down until the signal is not strong enough to be usable. The performance of Wi-Fi network also varies depending on the type of standard employed by the Wi-Fi devices, namely 802.11 (a), (b), (g), (n) and (ac).

Do you have a dead zone in your home with no wireless signal? You're not alone. With a proliferation of laptops, smartphones, tablets, and smart TVs; we use more Internet than ever, and your router alone may not be able to cover your entire home. You may even have a range extender or an access point that complements your home network, but having multiple networks within your home may cause your smart devices to hop on and off a separate network causing delays and interruptions.

Ethernet is the most widely used local area network (LAN) technology, that defines wiring and signaling standards for the physical layer of TCP/IP. Ethernet was originally standardized as IEEE 802.3 with a data transmission rate of 10 Mb/s. Newer versions of Ethernet were introduced lately to offer higher data rates. Fast Ethernet and Gigabit Ethernet support data rates of 100 Mbps and 1 Gbps (1000 Mbps) respectively. An Ethernet LAN may use coaxial cable (10Base2), unshielded twisted pair wiring (10BaseT, 100BaseT and 1000BaseT), or fiber optic cable. Ethernet devices compete for access to the network using a protocol called Carrier Sense Multiple Access with Collision Detection (CSMA/CD). With the prosperity of Internet, Wi-Fi, the wireless LAN technology standardized by IEEE 802.11, is used in hybrid with Ethernet LAN to offer portability.

You have a private or public network with servers and workstations that are assigned static and dynamic IP addresses (either private or public IPs). You assigned them the static IP addresses due to NAT (Network Address Translation) or for public access, and dynamic IP addresses via the DHCP. Even if you kept a good record of those assigned IPs, there are times when you want to find all IP addresses of networked devices. The following procedure may be used to determine IP addresses of networked devices that are connected to your network.

Often times we see a networked printer suddenly stop working and you need to find a static (private) ip address of the printer to diagnose further. How do we find IP address of a networked printer? There are a few different ways to go about finding it.

RJ-45 conductor data cable contains 4 pairs of wires each consists of a solid colored wire and a strip of the same color. There are two wiring standards for RJ-45 wiring: T-568A and T-568B. Although there are 4 pairs of wires, 10BaseT/100BaseT Ethernet uses only 2 pairs: Orange and Green. The other two colors (blue and brown) may be used for a second Ethernet line or for phone connections. The two wiring standards are used to create a cross-over cable (T-568A on one end, and T-568B on the other end), or a straight-through cable (T-568B or T-568A on both ends).

Denial of service attacks are major nuisance for web hosts, and as a web host you'll have to take every measure to protect your resources from DoS attacks. Our APF, BFD, DDoS and RootKit article describes Linux utilities available to protect from DDoS attack, and also explains installation procedures. This article supplements above article by providing means to control traffic (bandwidth shaping) with Linux "tc" command so that no single machine can waste the entire network bandwidth.

IP Spoofing is a technique used to gain unauthorized access to machines, whereby an attacker illicitly impersonates another machine by manipulating IP packets. IP Spoofing involves modifying the packet header with a forged (spoofed) source IP address, a checksum, and the order value. Internet is a packet switched network, which causes the packets leaving one machine may be arriving at the destination machine in different order. The receiving machine resembles the message based on the order value embedded in the IP header. IP spoofing involves solving the algorithm that is used to select the order sent values, and to modify them correctly.

Ipconfig is a MS-DOS command-line tool used to display and manage the network settings of your computer. Ipconfig is available on Windows machines, and it displays the current network connection details and DHCP client settings.