IPv6 Link Local Addressing
Link local addresses span a single subnet.
- not forwarded by routers
- nodes on same link are referred to as neighbors
- link local range:
fe80::/10- start with a leading
fe80 - next 54 bits set to 0
- last 64 bits are the interface ID
- start with a leading
- equivalent of Automatic Private IP Addressing (APIPA) and its
169.254.0.0addresses- but an IPv6 host is always configured with link local addresses for each link
- even if it has a global address
- but an IPv6 host is always configured with link local addresses for each link
- appended with a zone index (scope id)
- form %1 (Windows) or %eth0 (Linux)
- used to define the source of the address and make it unique to particular link
- E.g., given host may have links to a loopback address, Ethernet, and VPN
- each of these links may used the same link local address
- so each is assigned a zone ID to make it unique
- zone indices are generated by the host system
- where two hosts communicate, they may be referring to the link using different zone IDs
Info
- uncommon for an interface to have more than one IPv4 address
- but typical for an interface to have multiple IPv6 addresses