The term port knocking refers to a type of host-to-host communication where the information flows across closed ports. The primary purpose of port knocking is to keep attackers from successfully conducting a port scan since the server will require the correct port knocking protocol or sequence before the port is opened. There are a few types of port knocking methods, including encoding information in a packet-payload or a port sequence. When the port knocking method is used, the data is sent to
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Two of the most popular technologies that offer speedy access to the World Wide Web are DSL broadband and the cable modem. There are several reasons why this is the case and the first one is that both of these Internet connections are considerably faster than the standard dialup connections. However, when you compare the speed of data transfer between DSL and a cable modem there is a bit of variance depending on various technical aspects. Because of these variances DSL and the cable modem might
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traceroute is a command which is used to trace the route of a packet through a TCP/IP network.
traceroute is a Unix command. Under Microsoft Windows, the traceroute command has been renamed `tracert`. Unix `traceroute` and Microsoft Windows `tracert` are designed to accomplish the same task, but differ in the way they display output, in the way they send test packets, and in the number of command line options they provide.
Sample `tracert` output
This is the result of tracing the network ro
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ISDN BRI (Basic Rate Interface) is a standard Integrated Services Digital Network (ISDN) service meant for residential and small scale business Internet connections. There is another type of ISDN configuration called the Primary Rate Interface (PRI) that is designed to provide higher bandwidth. The BRI configuration defined in the physical layer standard I.430 produced by the ITU.
Both the BRI and PRI are designed similarly. That is, both make use of the B and D channels for data communicatio
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The Interior Gateway Routing Protocol (IGRP) is a network routing protocol that is designed to enable routing inside of an Autonomous System (AS). Cisco developed this protocol in the late 1980s in response to the existing Routing Information Protocol's (RIP) shortcomings. As Cisco routers became more popular, a number of large networks began using IGRP, which the enhanced ITRP replaced in the early 1990s in order to improve the overall efficiency of network routing.
How does the Interior Gatew
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A personal firewall is a firewall-like software application which runs on a users PC.
Traditional software-based firewalls run as the only application on stand-alone computers which have been hardened to protect against hackers. Personal firewalls run on PC's along with all of the other applications required by the PC user.
Traditional firewalls protect entire networks. Personal firewalls are normally designed to protect only the PC upon which they are installed.
Because they run on the
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RG-58 is a coaxial cable that is used for wiring purposes. A coaxial cable, in general, consists of an inner conductor that is surrounded by a spacer. The coaxial cable is electrically charged and sometimes consists of different uninsulated conductors that remain entangled with one another. The insulating spacer of the cable is further surrounded by a sheath that is cylindrical in shape. The final circle is formed by an insulating jacket. The insulation surrounding the RG-58 cable carries a low
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SIP (Session Initiation Protocol) is an IETF standard multimedia conferencing protocol, which includes voice, video, and data conferencing, for use over packet-switched networks.
SIP is an open standard replacement for the ITU's H.323.
SIP is described in RFC 3621 - SIP: Session Initiation Protocol.
SIP is an application-layer control (signaling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, mult
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The system that helps connect a computer to an Ethernet network is called an Ethernet card. Another name for such a card is Network Interface Card (NIC). It can be inserted into one of the slots provided on the motherboard of the computer. Each of these cards has a unique identification number, known as the MAC address.
Ever since their inception by the Xerox Company, Ethernet cards have managed to find their way into nearly every single computer in the world.
The Ethernet Card – An Easi
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Digital Subscriber Line or Digital Subscriber Loop (DSL) is a type of high-speed Internet technology that enables transmission of digital data via the wires of a telephone network. DSL does not interfere with the telephone line; the same line can be used for both Internet and regular telephone services. The download speed of DSL ranges between 384 Kbps and 20 Mbps. The most popular implementation of DSL today is Asymmetric Digital Subscriber Line (ADSL). It is asymmetric because the upload and d
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