For Geeks @nd the not so Geeky

Network Interfaces – Network Interface Card (NIC)

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 Cardhttp://www.howstuffworks.com/home-network.htm

Network Interface Card Types Considerations network interface card types

  • 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)
Unit Bytes Bits
Bit (b) 1/8 byte 1 bit
Byte (B) 1 byte 8 bits
KiloByte (KB) 1000 bytes 8000 bits
MegaByte (MB) 1 million bytes 8 million bits
GigaByte (GB) 1 billion bytes 8billion bits
TerraByte 1 trillion bytes 8 trillion bits

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.

Base Value 27 26 25 24 23 22 21 20
Exponent 128 64 32 16 8 4 2 1

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:
IP Address 00001010 00001010 00010111 10000110
Network Mask 11111111 00000000 00000000 00000000
Network Address 00001010 00000000 00000000 00000000

 

 

 

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