Ipv6 address types, Unicast addresses – Cisco ASA 5505 User Manual

Page 1888

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B-6

Cisco ASA 5500 Series Configuration Guide using the CLI

Appendix B Addresses, Protocols, and Ports

IPv6 Addresses

Note

Two colons (::) can be used only once in an IPv6 address to represent successive fields of zeros.

An alternative form of the IPv6 format is often used when dealing with an environment that contains
both IPv4 and IPv6 addresses. This alternative has the format x:x:x:x:x:x:y.y.y.y, where x represent the
hexadecimal values for the six high-order parts of the IPv6 address and y represent decimal values for
the 32-bit IPv4 part of the address (which takes the place of the remaining two 16-bit parts of the IPv6
address). For example, the IPv4 address 192.168.1.1 could be represented as the IPv6 address
0:0:0:0:0:0:FFFF:192.168.1.1 or ::FFFF:192.168.1.1.

IPv6 Address Types

The following are the three main types of IPv6 addresses:

Unicast—A unicast address is an identifier for a single interface. A packet sent to a unicast address
is delivered to the interface identified by that address. An interface may have more than one unicast
address assigned to it.

Multicast—A multicast address is an identifier for a set of interfaces. A packet sent to a multicast
address is delivered to all addresses identified by that address.

Anycast—An anycast address is an identifier for a set of interfaces. Unlike a multicast address, a
packet sent to an anycast address is only delivered to the “nearest” interface, as determined by the
measure of distances for the routing protocol.

Note

There are no broadcast addresses in IPv6. Multicast addresses provide the broadcast functionality.

This section includes the following topics:

Unicast Addresses, page B-6

Multicast Address, page B-8

Anycast Address, page B-9

Required Addresses, page B-10

Unicast Addresses

This section describes IPv6 unicast addresses. Unicast addresses identify an interface on a network node.

This section includes the following topics:

Global Address, page B-7

Site-Local Address, page B-7

Link-Local Address, page B-7

IPv4-Compatible IPv6 Addresses, page B-7

Unspecified Address, page B-8

Loopback Address, page B-8

Interface Identifiers, page B-8

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