Link Local Address

Link local address is a special type of address intended for communications within the local network segment or a point-to-point connection.  Routers do not forward packets with link local address.

If you would recall, if a host doesn't have any IP address assigned and also failed to receive a DHCP address, the host gets assigned an address within the block.  That is an IPv4 link local address.  In IPv6, the equivalent link local address gets a FE80::/10 prefix.

Although this type of address are not routable, meaning it's not inteded to be routed on the public internet but instead to be routed within a site or organization.  It is required for IPv6 sublayer operations of the Neighbor Discovery Protocol and used for stateless autoconfiguration; through which, the host can get additional IPv6 addresses assigned to its interfaces.

One can identify an IPv6 Link Local Address by examining its first 10 bits, it should match 1111111010 which when padded with 2 additional 0's to form 3 hexadecimal digits should yeild FE8 and finally form FE80::/10 in CIDR format.

Click on this link to examine Link Local address using the Advanced Online IPv6 Subnet Calculator: FE80:0000:0000:0000:0000:5AFE:00AA:20A2