General Networking - Monday, July 14, 2008 14:16 - 0 Comments

Default ip address ranges and subnetting overview

IP Address Ranges And Subnetting

Every peripheral connected to a TCP/IP network gets assigned an IP address. This address is a 32 bit number that identifies the peripheral on a network. In short, this address helps the router send the information packet to the correct host. Besides the IP address, subnet masks are required for TCP/IP to function. This mask allows the network protocol to decipher where the host is, either local or remote. A subnet mask is also a 32 bit number broken down into octets. Using the subnet mask along with the IP address whether the host is local or not can be determined.

Internet RFC 1878 defines valid subnets and subnet masks that can be used. Subnet masks are divided into three classes A, B, and C. Each class has a default subnet mask and default range for their first octet of its IP address. Class A uses 255.0.0.0 and 0-127 as a first octet. Class B uses 255.255.0.0 and 128-191 as a first octet. Finally Class C uses 255.255.255.0 and 193-223 as their first IP address octet. If these subnet masks do not fit a network for any circumstance subnetting can be used to divide the network.

IP addresses come in both public and private form, each having its own range. Private IP addresses are used most commonly for networks that do not access the Internet. Private IP addresses cannot be accessed from the Internet and cannot access the Internet. The range of private IP addresses are 10.0.0.0 through 10.255.255.255, 169.254.0.0 through 169.254.255.255 (APIPA only), 172.16.0.0 through 172.31.255.255 and 192.168.0.0 through 192.168.255.255. Public IP addresses can be accessed from the Internet and can access the Internet. Ranges of public IP addresses are all other addresses except very few rare ones in the high end range for multi/ unicast/ research starting at around 248.x.y.z.

Article written by MyComputerAid.com