There are a number of IP addresses that cannot be used for conventional unicast addresses. We have seen how addresses types can be link-local or ULA addresses, but there are some more that will be summarized in the following points:

• :: / 128: An unspecified address, equivalent to 0.0.0.0 in IPv4
• :: 1/128: Represents the loopback address, such as 127.0.0.1 in IPv4
• fc00 :: / 7: Belongs to the range of ULA addresses
• fc00 :: / 8: Still pending definition and reserved
• fd00 :: / 8: Defines a range of ULA addresses. IP addresses are constructed by generating a random 40-bit string, and by adding the prefix to make a 64-bit network address
• ff00 :: / 8: Multicast addresses, equivalent to the 224.0.0.0/4 IPv4 range
• fe80 :: / 10: Belongs to the link-local addresses, equivalent to the 169.254.0.0/16 range in IPv4