IPv6 (type of IPv6 address)

IPv6 (type of IPv6 address)

IPv4 addresses are classified into the following three types.

IPv4 typeUsage
unicast addressAddress used for one-to-one communication.
broadcast addressAn address used to send data to multiple computers on a network all at once.
multicast addressAn address used to send identical information to selected groups within a network.

IPv6 addresses are classified into the following three types.

Anycast, which is not in IPv4, has been added, and broadcast, which was in IPv4, is gone.

IPv6 type classification Usage
unicast address global unicast address Address used for one-to-one communication.
Site-local unicast address (deprecated)
unique local unicast address
link-local unicast address
multicast address - An address that is equivalent to IPv4 multicast and is used to send the same information to selected groups within the network.
multicast address - A new address type from IPv6, used when communicating with the closest partner in terms of network.

unicast address

 Addresses used for one-to-one communication, including global unicast addresses, site-local unicast addresses, unique local unicast addresses, and link-local unicast addresses that can be aggregated.

 Site-local unicast addresses have been deprecated in favor of unique local unicast addresses.

multicast address

 Equivalent to IPv4 multicast, this address is used to send the same information to selected groups within the network.

 The broadcast address, which in IPv4 meant all hosts on the same network, is part of the multicast address, so in IPv6 it is included in the multicast address.

 In IPv6 there are no broadcast addresses. All uses that were previously done with broadcasting also use multicast.

anycast address

 This is a new address type from IPv6 and is used when communicating with the closest partner in terms of network. Anycast addresses allow multiple hosts to have the same anycast address. Although it is a global address, duplication is allowed. Locality is now determined by routing protocol metrics.

IPv6 scope

 IPv6 addresses include unicast addresses with a single destination, multicast addresses with multiple destinations, and anycast with the nearest destination. Those addresses have three different scopes.

IPv6 scopeexplanation
link localAn IPv6 address that is valid only on one local link (broadcast domain). Assigned during automatic configuration.
globalAn IPv6 address with unlimited scope, used throughout the Internet.
Site-local (deprecated)An IPv6 address that is used only inside a local intranet site.
Deprecated with little use.

 An IPv6 node always has a link-local address and may have one or more global addresses. It may also have a site-local address, although it has been decided to abolish it.

IPv6 address type and prefix

 The table below shows the relationship between IPv6 addresses and prefixes. If you remember the IPv6 address prefix, you can tell what kind of IPv6 address it is. Remember.

prefixbinary prefixUsage
0::/800000000...Unspecified, loopback
unspecified ... "::"
Loopback ... "::1"
2000::/3001...global unicast address
FC00::/71111110...unique local unicast address
FE80::/101111111010...link-local unicast address
FEC0::/101111111011...Site-local unicast address (deprecated)
FF00::/811111111...multicast address

well-known multicast address

The table below shows the relationship between typical multicast addresses and prefixes.

prefixUsage
FF02::1/128all nodes
FF02::2/128all routers
FF02::9/128All RIP routers
FF02::1FF00:0/104solicited-node multicast address. Used for address resolution of IPv6 addresses and MAC addresses.