fe80::/10 (IPv6 Link-Local)
Not routableRFC 4291
fe80::/10 at a glance
| CIDR block | fe80::/10 |
|---|---|
| First address | fe80:: |
| Last address | febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff |
| Total addresses | 2¹¹⁸ |
| Prefix mask | ffc0:: |
| Prefix length | /10 |
| Type | Not routable |
| Publicly routable | No |
| Defined in | RFC 4291 |
What is fe80::/10 used for?
fe80::/10 is the IPv6 link-local range. Every IPv6 interface configures an fe80:: address automatically and uses it for neighbor discovery and router advertisements. These addresses are valid only on the local link, so they often need a zone ID such as fe80::1%eth0. In practice they come from fe80::/64.
FAQ
Why does every IPv6 interface have an fe80:: address?
IPv6 requires a link-local address on each interface for neighbor discovery and router advertisements. It is created automatically, even without a router or DHCP.
What does %eth0 mean after an fe80:: address?
It is the zone ID. The same fe80:: prefix exists on every link, so you must say which interface to use, for example ping fe80::1%eth0 (Linux) or fe80::1%12 (Windows).