Network Interface Card & Internet Connection Requirements

• Physical connection – modem or network interface card (NIC) allow the local network to connect to the Internet
• Logical connection – standard protocols are a set of rules and conventions defining how the physical devices communicate. Transmission Control Protocol/Internet Protocol (TCP/IP) is the primary, most used protocol
• Application – applications translate the data transmitted to a form that can be read by humans such as a web browser or an  FTP program and the various plugins to display video and text or play sound.

Network Card – http://www.howstuffworks.com/home-network.htm

Network Interface Card Types Considerations

• Protocols – Ethernet, Token Ring or Fiber Distributed Data Interface (FDDI)
• Types of media – Twisted-pair, coaxial, wireless or fiber-optic
• Type of system bus – PCI or ISA

Install Network Interface Card Situations

• Installation of a NIC on a PC that does not already have one
• Replacement of a malfunctioning or damaged NIC
• Upgrade from a 10-Mbps NIC to a 100/1000-Mbps NIC
• Change to a different type of NIC, such as wireless
• Installation of a secondary, or backup, NIC for network security reasons

Network Interfaces – http://en.wikipedia.org/wiki/Network_interface

Network Interface Card Troubleshooting Requirements

• Knowledge of how the adapter, jumpers, and plug-and-play software are configured. Most modern day NICs are plug_and_play and only require the software or driver to be installed.
• Availability of diagnostic tools such as a loopback test
• Ability to resolve hardware resource conflicts such as IRQ, DMA or IO conflicts

Transmission Control Protocol/Internet Protocol (TCP/IP)

• TCP/IP is a set of protocols developed to allow computers to communicate with each other.
• TCP/IP can be configured using operating system tools
• TCP/IP requires the PC to be configured with an IP address, subnet mask, default gateway and Domain Name System (DNS) information

Network Interface Card Problems – Ping

• ping 127.0.0.1 – This is a unique ping and is called an internal loopback test. It is used to verify the basic TCP/IP network configuration.
• ping IP address of host computer – A ping to the local host PC verifies the TCP/IP address configuration for the local host and connectivity to the host.
• ping default-gateway IP address – A ping to the default gateway indicates if the router that connects the local network to other networks can be reached.
• ping remote destination IP address – A ping to a remote destination verifies connectivity to a remote host.

Bits and Bytes – Base 2 Numbering System

• Computers recognize and process data using the binary number system
• 1 bit represents a single address storage location for data such as an ASCII code
• 8 bits represent 1 byte leaving a combination of 256 or 2⁸ when adding all the possible combinations of the 8 bits turned off (0) or on (1)
• Most coding uses 1 byte to represent a number, symbol or character
• Data Bits – Do not confuse MegaBytes (MB) with MegaBits (Mb)

The above table shows approximate values as 1 Kb is really 1024 bytes when talking about data storage bits as opposed to data transfer bits or bytes.

Example

• 10110₂ = (1 x 2⁴ = 16) + (0 x 2³ = 0) + (1 x 2² = 4) + (1 x 2¹ = 2) + (0 x 2⁰ = 0) = 22
• 22₁₀ = 10110

Base 16 Numbering System – Hex

• The hexadecimal system is used when working with computers because it can be used to represent binary numbers in a more readable form (0123456789ABCDEF)
• Network adapter or NIC MAC addresses are represented by a string of 12 hexadecimal characters
• 55B1₁₆ = (5 x 16³ = 20480) + (5 x 16² = 1280) + (B x 16 = 176) + (1 x 16⁰ = 1) = (5 x 4096) + (5 x 256) + (11 x16) +(1 x 1) = 21937

IP Addresses and Network Masks

• The IP address 10.34.23.134 in binary form is 00001010.00100010.00010111.10000110
• IP addresses consist of 4 bytes or 4 8-bit octets which represent a 32-bit binary address
• A Boolean AND of the IP address 10.34.23.134 and the subnet mask 255.0.0.0 produces the network address of this host: