IPv6 Address Types and Scopes

IPv6 changed how addresses target devices. It dropped IPv4’s broadcast entirely. Instead, IPv6 uses three main address types: unicast, multicast, and anycast.

Each defines how many destinations a packet reaches, and addresses also carry a scope describing how far they are valid.

Unicast identifies a single interface; a packet sent to a unicast address goes to exactly one device. This is the everyday address type, like an IPv4 host address.

Most addresses you assign and use are unicast, whether for browsing, file transfer, or any one-to-one communication.

Multicast delivers a packet to all members of a group. IPv6 multicast addresses begin with ff00::/8 (they start with ff).

Multicast replaces broadcast for tasks like router discovery, efficiently reaching only interested devices rather than flooding the entire network.

Anycast assigns the same address to multiple devices, and a packet goes to the nearest one by routing distance.

Anycast is useful for services like DNS, where many identical servers share an address and each client is served by the closest. It looks like a unicast address but is configured on several nodes.

Global unicast addresses are the IPv6 equivalent of public IPv4 — globally routable on the internet. They commonly fall in the 2000::/3 range, so they typically start with 2 or 3.

These are the addresses devices use to communicate across the internet, unique worldwide.

Link-local addresses begin with fe80::/10 and are valid only on the local link. They are not routable beyond it.

Every IPv6 interface automatically gets a link-local address, used for neighbor discovery and local communication. They appear constantly and are essential to how IPv6 networks bootstrap.

Unique local addresses (ULAs) use the fc00::/7 range, in practice starting with fd. They are the rough equivalent of IPv4 private addresses.

ULAs are routable inside an organization but not on the public internet, ideal for internal communication that should never leave the local network.

Scope defines where an address is meaningful. Link-local scope stops at the local link; global scope spans the whole internet.

The same device can hold several addresses at once — a link-local for local tasks and a global unicast for internet access — each with its own scope and purpose.

You can identify an IPv6 address type by its opening digits:

• Starts with 2 or 3 → global unicast
• Starts with fe80 → link-local
• Starts with fc/fd → unique local
• Starts with ff → multicast

This quick triage speeds up reading any IPv6 configuration.

Holding several addresses lets a device handle different jobs cleanly. Neighbor discovery and on-link chatter use link-local, while internet traffic uses global unicast.

This separation is intentional and normal in IPv6, unlike IPv4 where an interface usually has just one address. Do not be surprised to see several addresses listed per interface.

Knowing the address types and scopes lets you read any IPv6 setup with confidence. Unicast reaches one device, multicast a group, and anycast the nearest of several.

Combined with global, link-local, and unique-local ranges, you can classify any address at a glance — the final piece before running IPv4 and IPv6 together.

Classify the address.

You learned IPv6 address types and scopes.

• IPv6 has no broadcast; it uses unicast, multicast, and anycast.
• Global unicast (2000::/3) is internet-routable.
• Link-local (fe80::/10) works only on the local link.
• Unique local (fc/fd) is the private-address equivalent.
• Multicast starts with ff; scope sets how far an address reaches.