There are a variety of different types of IP addresses. The most basic differentiating factor is whether a given IP address employs the IPv4 or IPv6 format. Let’s see how these two formats differ.

IPv4 An IPv4 address is comprised of four sets of numbers from 0 to 255. The four sets are separated by three dots, as in 123.123.255.255. There are three classes of IPv4 addresses, based on how many of the numerical blocks are variable.

IPv4 addresses range from 000.000.000.000 to 255.255.255.255 for a total of 4,294,967,296 possible IP addresses. While at one point this was thought to be sufficient for all worldwide computers, that has proven to be incorrect. To handle the growing numbers of network-connected devices, many now use the IPv6 format.

IPv6 In order to greatly expand the number of possible addresses, an IPv6 address consists of eight sets of four hexadecimal digits. This increases the address range to encompass 340,282,366,920,938,463,463,374,607,431,768,211,456 unique addresses. This should be sufficient for the foreseeable future. An example of an IPv6 address is 2001:0db8:0001:0000:0000:0ab9:C0A8:0102. Leading zeros are sometimes eliminated to allow compression. The preceding address in compressed form would be 2001:db8:1::ab9:C0A8:102.

All IP addresses will be of the IPv4 or IPv6 format, but there are other factors which differentiate IP addresses. Here are some categories of IP addresses with which you may want to gain some familiarity.