Learn Windows XP Professional: TCP/IP Addressing in Windows XP Professional (Page 4) Page 4

TCP/IP Class A Address Overview

The “A” class addressing scheme
has an official start address of 0.0.0.0 and an official
last address of 127.255.255.255. Not all of these address can be used, and you will OFTEN see
conflicting information on this.

1.0.0.1 to 126.255.255.254 is
the range of IP addresses that are included in the “A” class
addressing scheme that are the useable range for node
assignment

126.255.255.255 is a broadcast address and in most cases
cannot be assigned. (There are exceptions to the rule.)

The local host will use 0.0.0.0 when it cannot reach a DHCP
server when it is set to use one and cannot assign itself an
address using APIPA.

1.0.0.1 to 126.255.255.254 is the useable range. There are 126 Class A networks total, each allowed to have
up to 16,777,214 hosts. The 127.x.x.x range is used for internal host loopback.

There are three IP network addresses reserved for private
networks:  10.0.0.0 – 10.255.255.255 with the subnet
mask 255.0.0.0 is the range for Class A IP addresses.

They can be used by anyone setting up internal IP networks,
such as a lab or home LAN behind a NAT or proxy server or a
router. It is always safe to use these because routers on
the Internet will never forward packets coming from these
addresses.

These addresses are defined in RFC 1918.

While 10.0.0.0 – 10.255.255.255 addresses with the subnet
mask 255.0.0.0 are available only to internal IP networks,
they are still considered part of the Class “A” range.

TCP/IP Class B Address Overview

The “B” class addressing scheme
has an official start address of 128.0.0.0 and an official
last address of 191.255.255.255. Not all of these address can be used, and you will OFTEN see
conflicting information on this.

128.0.0.1 to 191.255.255.254 is the range of IP addresses
that are included in the “B” class addressing scheme that
are the useable range for node assignment.

The local host will use 0.0.0.0 when it cannot reach a DHCP
server when it is set to use one and cannot assign itself an
address using APIPA.

There are three IP network addresses reserved for private
networks:  172.16.0.0 – 172.31.255.255 with the subnet mask
255.240.0.0 is the range for Class B IP addresses.

They can be used by anyone setting up internal IP networks,
such as a lab or home LAN behind a NAT or proxy server or a
router. It is always safe to use these because routers on
the Internet will never forward packets coming from these
addresses.

These addresses are defined in RFC 1918.

While 172.16.0.0 – 172.31.255.255 addresses with the subnet
mask 255.240.0.0 are available only to internal IP networks,
they are still considered part of the Class “B” range.

TCP/IP Class C Address Overview

The “C” class addressing scheme
has an official start address of 192.0.0.0 and an official
last address of 223.255.255.255.

Not all of these address can be used and you will OFTEN see
conflicting information on this.

192.0.0.1 to 223.255.255.254 is the range of IP addresses
that are included in the “C” class addressing scheme that
are the useable range for node assignment.

The local host will use 0.0.0.0 when it cannot reach a DHCP
server when it is set to use one and cannot assign itself an
address using APIPA.

There are three IP network addresses reserved for private
networks:  192.168.0.0 – 192.168.255.255 with the subnet mask
255.255.0.0 is the range for Class C IP addresses.

They can be used by anyone setting up internal IP networks,
such as a lab or home LAN behind a NAT or proxy server or a
router. It is always safe to use these because routers on
the Internet will never forward packets coming from these
addresses.

These addresses are defined in RFC 1918.

While 192.168.0.0 – 192.168.255.255 addresses with the
subnet mask 255.255.0.0 are available only to internal IP
networks, they are still considered part of the Class “C”
range.