IPv6 Link-Local Calculator
Derive the fe80::/10 link-local address a host will use from its MAC address, with the zone identifier.
About IPv6 Link-Local Calculator
Link-local addresses are formed automatically on every IPv6 interface from the fe80 prefix plus an interface identifier. Because the same address can exist on several links, a zone identifier selects the interface. The solicited-node multicast address is derived from the last 24 bits and is what neighbour discovery targets. Link-local addresses are what routing protocols such as OSPFv3 and BGP peer over, so predicting them is routine when building or troubleshooting adjacencies.
Formula
IPv6 Link-Local
The fe80::/64 prefix is combined with the modified EUI-64 interface identifier derived from the MAC address.
- fe80::/10
- Reserved link-local prefix
- %zone
- Interface selector required because link-local addresses are ambiguous
Worked example
With the default values below, IPv6 Link-Local Calculator returns Link-Local Address of fe80::21a:2bff:fe3c:4d5e. Change any input above and every figure here is recalculated in your browser.
Inputs used
- MAC address
- 00:1a:2b:3c:4d:5e
- Interface / zone name
- eth0
Results
- Link-Local Address
- fe80::21a:2bff:fe3c:4d5e
- Scoped Address
- fe80::21a:2bff:fe3c:4d5e%eth0
- Solicited-Node Multicast Address
- ff02::1:ff3c:4d5e
- Prefix
- fe80::/10
Step by step
- 1Values used
- 2IPv6 Link-Local
- 3Link-Local Address= fe80::21a:2bff:fe3c:4d5e
- 4Scoped Address= fe80::21a:2bff:fe3c:4d5e%eth0
- 5Solicited-Node Multicast Address= ff02::1:ff3c:4d5e
- 6Prefix= fe80::/10
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is IPv6 Link-Local calculated?
The fe80::/64 prefix is combined with the modified EUI-64 interface identifier derived from the MAC address. Link-local addresses are formed automatically on every IPv6 interface from the fe80 prefix plus an interface identifier. Because the same address can exist on several links, a zone identifier selects the interface. The solicited-node multicast address is derived from the last 24 bits and is what neighbour discovery targets.
Why does IPv6 Link-Local matter?
Link-local addresses are what routing protocols such as OSPFv3 and BGP peer over, so predicting them is routine when building or troubleshooting adjacencies.
What values do I need to enter?
This calculator takes 2 inputs: MAC address, Interface / zone name. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.