A class a addresses has the first octet full in the

Info icon This preview shows pages 27–29. Sign up to view the full content.

View Full Document Right Arrow Icon
used to determine default subnet masks. A Class A addresses has the first octet full in the subnet mask. A Class B address has the first and second octets full in the subnet mask. A Class C address has the third octet of the mask full. And Class D and E addresses are used for special purposes. Network devices use addresses to identify other devices. These addresses are used to send and receive packets of electronic data over the network. The addresses used depend on the physical topology of the network as well as the protocols being used. Each network device is identified using a physical address. For Ethernet networks, the physical device address is the MAC address. The MAC address is a unique hexadecimal identifier burned into the ROM (physically assigned address) of every network interface. The MAC address is a 48-bit, 12-digit hexadecimal number (each number ranges from 0–9 or A–F). The address is often written as 00-B0-D0-06-BC-AC or 00B0.D006.BCAC (although dashes, periods, and colons can also be used to divide the MAC address segments). The MAC address is guaranteed unique through design. o The first half (first 6 digits) of the MAC address is assigned to each manufacturer. o The manufacturer determines the rest of the address, assigning a unique value which identifies the host address. A manufacturer that uses all of the addresses in the original assignment can apply for a new MAC address assignment. Although some network cards allow you to change the MAC address (or specify one of your own choice), this is rarely done in practice. When you change the network card, the host will have a new physical device address. When you move a device to another network, the physical address remains the same (as long as the network card has not been changed).
Image of page 27

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
In addition to the physical device address, two logical addresses are also used. The logical network address identifies a network segment (called a subnet ). All devices on the same network segment share the same logical network address. The logical host address identifies a specific host on the network. Each device must have a unique logical host address. The format for the logical addresses used depends on the protocol suite. With TCP/IP, the logical network and logical host addresses are combined into a single address called the IP address. An IP address: Is a 32-bit binary number represented as four octets (four 8-bit numbers). Each octet is separated by a period. Can be represented in one of two ways: o Decimal (e.g., 131.107.2.200). In decimal notation, each octet must be between 0 and 255. o Binary (e.g., 10000011.01101011.00000010.11001000). In binary notation, each octet is an 8-digit number. Includes both the network address and the host address. Uses a subnet mask to differentiate the network and host addresses.
Image of page 28
Image of page 29
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern