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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.

Proxy server is a computer that sits between a client computer and the Internet, and provide indirect network services to a client. It may reside on the user's local computer, or at various points between the user's computer and destination servers on the Internet. A proxy server intercepts all client requests, and provide responses from its cache or forwards the request to the real server. A client computer is connected to the proxy server, which acknowledges client requests by providing the requested resource/data from either a specified server or the local cache memory. Client requests include files or any other resources available on various servers.

The Dynamic Host Configuration Protocol (DHCP) is a network protocol which functions at the application layer of the Internet Protocol (IP) suite. A server which 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 of networks of any sizes, 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 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.

MAC, Media Access Control, address is a globally unique identifier assigned to network devices, and therefore it is often referred to as hardware or physical address. MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format. The first 3-bytes are ID number of the manufacturer, which is assigned by an Internet standards body. The second 3-bytes are serial number assigned by the manufacturer.

With ever growing number of spam emails flooding the Internet, more and more ISPs tighten their email filtering system to prevent spams delivered to their clients. It is virtually impossible to block even 50% of the spams arriving in a mail server, and there will always be false positives (legitimate emails filtered as spams). In an effort to reduce spam emails, the Federal Trade Commision (FTC) passed the CAN-SPAM Act of 2003, but the Internet spam traffic is still on the rise.