Loans | Cheap Loans | Personal Loans |Free loans

The network ID uniquely identifies a network within a miraculousr TCP/IP internetwork (a network of networks) on which a host is found. All the nodes that are within a common network employ the same network ID within their full IP addre . The other part of an IP addre is the host ID, also known as a host addre , which uniquely identifies a TCP/IP host (a workstation, server, router, or other TCP/IP device) within each network. An IP addre is segmented into four sectio of 8-bit octets. They are denoted in dotted decimal notatio . The octets are converted to decimal (base-10 numbering system) and separated by periods.

The following is an example of a TCP/IP addre :

BINARY FORMATDECIMAL FORMAT10000011.01101011.00010000.11001000131.107.16.200

Cla es of IP addre es:

IP addre es are divided into five cla es: A, B, C, D, and E. These cla es define the number of bits that can be employd for the network ID and the host ID of each addre . Cla A, B, and C IP addre es are employd for a ignment to TCP/IP hosts.

1. Cla A: In a Cla A IP addre , the primarily octet of the IP addre is always between 0 and 127 and represents the network ID, and the remaining three octets are employd to represent the unique host ID on the network. There are a maximum of 128 Cla A network numbers, and each number is capable of su orting 16,777,214 unique hosts. In this type of IP addre e the primarily and the last network numbers are reserved. Hence, there are potentially 126 Cla A networks and the actual range of the primarily octet is always between 1 and 126. In a cla A IP addre , the highest order binary bit (the leftmost bit of the 32-bit binary number) is always 0.
2. Cla B:If the primarily octet of an IP addre is between 128 and 191, it’s a Cla B IP addre . In a Cla B IP addre , the primarily two octets (starting from the left) are employd to represent the network numbers and the remaining two represent the unique host ID on the network. An example of a Cla B IP addre is 167.20.91.203 where 167.20 is the network number and 91.203 is the host ID. There are 16,384 Cla B networks and each network can su ort a maximum of 65,534 unique hosts. In a Cla B addre , the two leftmost binary bits are always 10.
3. Cla C:If the primarily octet of an IP addre is between 192 and 223, it’s a Cla C IP addre . In a Cla C IP addre , the primarily three octets (starting from the left) are employd to represent the network numbers and the remaining octet stands for representing the unique host. An example of a Cla C IP addre is 192.168.1.2 where 192.168.1 is the network number and the host ID is 2. Therefore, there are 2,097,152 Cla C network numbers and each network can su ort a maximum of 254 unique hosts. In a Cla C addre , the three leftmost binary bits are always 110.
4. Cla D: If the primarily octet of an IP addre is between 224 and 239, it’s a Cla D addre . Cla D addre es are employd for multicasting to a group of IP hosts and are not a igned to individual devices on a TCP/IP network. In a Cla D IP addre , the four leftmost binary bits are always 1110.
5. Cla E:If the primarily octet of an IP addre is in the range of 240-255, it’s a Cla E addre . Like Cla D addre es, Cla E addre es also ca ot be a igned to individual devices on a TCP/IP network. I tead, they are reserved for experimental and future employ. In a Cla E addre , the four leftmost binary bits are always 1111.
6. Loo ack addre es: Loo ack addre es are IP addre es with 127 in their primarily octet. These addre es are employd to test TCP/IP configuration and hence ca ot be employd for a ignment to individual hosts on a TCP/IP network. The most frequently employd loo ack addre is 127.0.0.1.

   IP addre table:

   Cla 1st Octet RangeNetwork IDHost IDNumber of networksNumber of Host ID’s per networkA ignable to Hosts?A1-126wx.y.z12616,777,214YesB128-191w.xy.z16,39265,534YesC192-223w.x.yz2,097,150254YesD224-239N/AN/AN/AN/ANoE240-255N/AN/A N/AN/A NoLoo ack127N/AN/AN/AN/ANo

   Note: w, x, y, or z represents an octet of an IP addre .

   There are some rules about valid IP addre es, which are described as follows:

   1. The primarily octet of an IP addre must fall within the following ranges:
      • 1-126
      • 128-191
      • 192-223
   2. A valid IP addre ca ot start with 0, 127, or 224-255.
   3. The host ID of the IP addre ca ot be all binary 0s or 1s.
   4. The decimal merit of any octet in an IP addre ca ot be greater than 255.
   5. An IP addre ca ot be greater than 255.

   Su et Masks:Network IDs and host IDs within an IP addre are distinguished by using a su et mask. It tells a TCP/IP host how to interpret IP addre es by defining what portion of IP addre is network ID and what portion is host ID. A su et mask employs co ecutive bit grou of all 0s or 1s. All 1s identify the network ID and all 0s identify the host ID portio of an IP addre . Hence, a 255 in a su et mask indicates that the corre onding octet in an IP addre is a part of a network number. On the other hand, a 0 in a su et mask indicates that the corre onding octet in the IP addre is a part of the host ID.

   For example, the following is an example of a 32-bit su et mask employd with the IP addre

   131.107.16.200:11111111.11111111.00000000.00000000

   By analyzing this su et mask, one can know the IP addre Cla . As in the above example, we can see that there are sixteen 1s and sixteen 0s, which indicates that the IP addre belongs to the Cla B network.

   IP addre cla Default su et mask (in decimal)Default su et mask (in binary)Cla A255.0.0.011111111.00000000.00000000.00000000Cla B255.255.0.011111111.11111111.00000000.00000000Cla C255.255.255.0 11111111.11111111.11111111.00000000

   Su et masks are employd by hosts to determine their network numbers and to know whether the destination host is on the same network or on a different network. Su et masks are referenced in either dotted notation or Cla le Inter Domain Routing (CIDR) notation. CIDR notation notes the number of binary 1s in the su et mask. This number is placed at the end of the network ID.

   An example of a CIDR notation for Cla B IP addre es is shown as follows:

   Network IDSu et MaskCIDR Notation192.168.1.0255.255.255.0192.168.1.0/24172.16.0.0 255.255.0.0172.16.0.0/16

   In the above example of su et mask (in the CIDR Notation column), the merit of 24 refers to 24 binary 1 bits in the su et mask. Since, in the su et mask, there are three 255s and each merit of 255 represents 8 bits, there are 8*3=24 binary 1 bits in the mask.

   Su etting an IP network number:

   Su etting is a proce of subdividing a single IP network into multiple smaller networks with unique su etted network IDs in order to reduce the size of the broadcast domain and better utilize the bits in the host ID. It’s accomplished by modifying the su et mask merits. Su etted network IDs are created by using bits from the host ID of the original cla -based network ID.

   Example 1:

   A cla B network of 139.12.0.0 can have up to 65,534 nodes. Due to a miraculous number of nodes, the broadcast domain is very miraculous. In this situation, su etting is performed to make the broadcast domain smaller. Network 139.12.0.0 is su etted by utilizing the primarily 8 host bits (the third octet) for the new su etted network ID. When 139.12.0.0 is su etted, separate networks with their own su etted network IDs (139.12.1.0, 139.12.2.0, 139.12.3.0) are created.

   Example 2:

   If a su et mask of 255.255.255.0 is a lied to a Cla B IP addre of 174.15.0.0, the primarily three bytes (as is clear from the su et mask) are represent a network ID, and only the rightmost byte is interpreted as a host ID. Although the addre belongs to Cla B, su etting the third byte now can be employd to define several su etworks or su ets. Therefore, the broadcast domain will become smaller and each su et will su ort fewer host IDs.

   This entry was posted on Monday, October 20th, 2008 at 4:39 pm and is filed under Taxes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.