IPv6 Link-Local Address Generator

Generate fe80:: link-local IPv6 addresses from MAC addresses using the EUI-64 method.

What Are Link-Local Addresses?

Link-local addresses (fe80::/10) are automatically assigned to every IPv6 interface. They are only valid on the local network segment and are never routed. Link-local addresses are essential for IPv6 neighbor discovery, router advertisements, and local communication — even before any global or delegated prefix is configured.

How Link-Local Generation Works

Component	Bits	Value
Link-Local Prefix	10 bits	fe80 (1111 1110 10)
Zero padding	54 bits	All zeros
Interface ID (EUI-64)	64 bits	Derived from MAC

The Interface ID is generated using the EUI-64 method: split the MAC, insert FFFE, flip bit 7.

Pro Tip: Link-local addresses are used for neighbor discovery, DHCPv6, and router solicitation. Even if you don't have a global IPv6 address, link-local allows local communication. When troubleshooting IPv6, always check link-local connectivity first with ping6 fe80::1%eth0. The zone ID (%eth0) is required because the same link-local can exist on multiple interfaces.

Note: Unlike global unicast addresses, link-local addresses cannot be changed or removed without disabling IPv6 entirely. They are fundamental to IPv6 operation. Every device on your network has one, making them useful for device identification. Use our MAC Lookup to identify the vendor from the MAC, and What Is My IP to check your global IPv6 address.

Common Uses of Link-Local Addresses

Protocol	Uses Link-Local	Purpose
NDP (Neighbor Discovery)	fe80:: addresses	ARP equivalent, router discovery
DHCPv6	Client → Server	Address and prefix delegation
OSPFv3	Router adjacencies	Routing protocol peering
Router Advertisements	fe80:: source	Default gateway announcement

Key Takeaways

Link-local addresses (fe80::) are auto-assigned to every IPv6 interface using EUI-64 from the MAC.
They are never routed — only valid on the local link/segment.
Essential for neighbor discovery, DHCPv6, and routing protocol operation.
Always specify the zone ID (%interface) when using link-local addresses in commands.
Use EUI-64 Calculator to understand the MAC-to-IPv6 conversion process.

Video Guide

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Frequently Asked Questions

What is an IPv6 link-local address?

A link-local address (fe80::/10) is automatically assigned to every IPv6 interface. It is only valid on the local network segment and never routed.

Do I need to configure link-local addresses?

No, they are generated automatically. Every IPv6 interface gets a link-local address as soon as IPv6 is enabled.

Why do I need a zone ID with link-local?

Because the same link-local address can exist on multiple interfaces. The zone ID (%eth0) tells the system which interface to use.

Can I change my link-local address?

On most systems, yes. You can manually configure a link-local address, but the auto-generated one is sufficient for normal operation.

Are link-local addresses secure?

They reveal your MAC address via EUI-64, but since they are only visible on the local network, the privacy risk is minimal compared to global addresses.

About Tommy N.

Tommy is the founder of RouterHax and a network engineer with 10+ years of experience in home and enterprise networking. He specializes in router configuration, WiFi optimization, and network security. When not writing guides, he's testing the latest mesh WiFi systems and helping readers troubleshoot their home networks.