IPv6 Addressing

Address Exhaustion

running out of network addresses in IPv4

IPv4 vs 6

4: has 32 bits, 4.3 billion addresses available, dotted octet notation

6: has 128 bits, 340 undecillion addresses available, uses hexadecimal digits and allows the use of shorthand notation, colons

IPv6 shorthand rules

• if a segment contains four consecutive zeros, it can be represented by one zero

  • ex: 2018 : 0000 : 0000 : 0000 : 0000 : 0000: 4815 :54ae →

    2018 : 0 : 0 : 0 : 0 : 0 : 4815 : 54ae

• the double colon “ : :” can be applied only once within an address

  • ex: 2018 : 0000 : 0000 : 0000 : 0000 : 0000: 4815 :54ae →

    2018 : : 4815 : 54ae

MAC vs IPv6 address

MAC: 6 groups of 2 seperated by colons

IPv6: groupings of 4, double colons

Unicast Address

used to identify a single interface

• globally-routed: similar to IPv4’s unicast class A, B, and C addresses and begins with 2000-3999

Link-Local/Local Use

used like a private IP in IPv4 that can only be used on the local area network and begins with FE80

Stateless Address Autoconfiguration (SLAAC)

eliminates the need to obtain addresses or other configuration information from a central server

• both EUI-64 and NDP are used with it

Multicast Address

used to identify a set of interfaces and begins with FF

Anycast Address

used to identify a set of interfaces so that a packet can be sent to any member of a set

Extended Unique Identifer (EUI)

allows a host to assign itself a unique 65-bit IPv6 interface identifier called EUI-64

DHCPv6 Protocol

allows DHCP to automatically assign addresses from a DHCPv6 server

Neighbor Discovery Protocol (NDP)

used to determine the Layer 2 addresses that are on a given network

exam things to know

• IPv6 addresses are 128 bits, while v4 are 32

• shorthand notation and zero compression

• IPv6 is written in hexadecimal, not in decimal

• 3 different types of ipv6 addresses: unicast, anycast, multicast