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.

The Dynamic Host Configuration Protocol (DHCP) is a network protocol that functions at the application layer of the Internet Protocol (IP) suite. A server that uses DHCP will be able to dynamically assign IP Addresses and other network configuration parameters to devices on the network; thus, allowing communication to a second network. The protocol can be implemented in networks of any size, ranging from small home area networks (HANs) to large campus area networks (CANs) and even the networks used by Internet Service Providers (ISPs).

TCP/IP, Transmission Control Protocol/Internet Protocol, is the suite of two protocols, TCP and IP, used to interconnect network devices on the Internet. The TCP performs the handshake between the network devices to establish a socket. The socket remains open during the communication. The source TCP converts the data into packets and sends them to the destination TCP. The TCP performs acknowledgment for the successful delivery of the packets. If a packet drops on the way, the source TCP resends the packet. The IP layer is responsible for sending and receiving the data to the correct destination. The TCP/IP stack is comprised of the following layers.