IPv6 (site-local unicast address)

IPv6 (site-local unicast address)

The effective range (scope) of IPv6 address unicast is classified as follows.

  • global unicast address
  • Site-local unicast address (deprecated)
  • link-local unicast address

Site-local unicast addresses are described here.

A site-local unicast address is a unicast address that is valid only within the same site.

 The bit pattern "1111 11110 11", which in hexadecimal notation starts with "fec0::/10". For the same purpose as IPv4 private addresses, use IPv6 addresses freely on networks that are not connected to the Internet. Use is limited to use within a specific site.

Since the address structure does not have information that identifies the site itself, multiple sites may end up with duplicate addresses.

 Site-local unicast addresses were abolished by RFC3879, which came into force in September 2004, and unique local unicast addresses were defined as new local addresses in RFC4193.