CCNA Chapter 23: IPv6 Addressing and Subnetting

IPv6 Prefix

The slash notation for a range of addresses - functions nearly identically to IPv4 network subnet masks.

Interface ID

The range of addresses assigned to interfaces/devices, not encompassed by the prefix.

Global Unicast IPv6

A publicly unique IPv6 address-

Company requests access to an IPv6 address block-

Company is given a unique global /64 prefix-

Company assigns unique addresses solely within that prefix.

Global routing prefix

A single address used to represent the entire address space, for ease of routing in a public space.

Equivalent of a subnet ID; the prefix for a /48 is, for example, the first 12 hex digits of the full address with all other digits replaced with 0's.

Global unicast address range

Originally all addresses starting with 2 or 3; now, any address not otherwise reserved.

Multicast Address address range

FF:: - all addresses.

Link Local address range

FE80: - all addresses.

IPv6 Subnetting

Take the assigned prefix, then add until you get to /64. The number (ex. 48 + 16=64, x=16) is what most companies would use for their subnetting needs. Past that, aside from the larger numbers involved subnetting works as normal.

Stateless Address Autoconfiguration (SLAAC)

IPv6 protocol for automatically assigning addresses to interfaces.

Unique Local Unicast Address

Private IPv6 addresses that follow a set of rules.

1. Uses FD as first hex digits

2. Has a globally unique 40-bit ID, for a total of 48 bits.

3. Has a 16-bit subnet field, resulting in a /64 prefix.

Note that the globally unique ID means unique local addresses are also globally unique.