Week 1 - IPv6 Addressing

Why are IPv6 addresses needed in the current world?

• More and more IP-enabled devices are being introduced so new addressing was needed to connect these devices

how many bits does IPv6 addresses have?

128 bits

What other features does IPv6 have?

• End-to-End communication traceability

• Unicast, multicast and anycast addresses are now possible

• simplified header for improved router efficiency

• support for security using IPsec

What is a unicast address?

Unicast means 1-1 where an address is destined only specifically for one single interface

What is a Multicast address

Multicast means 1-many where a packet is sent to all interfaces identified by that address

What is an Anycast address

Anycast means 1 - nearest where a packet is sent to the closest interface determined by the IGP

What are the new features of IPv6?

• Improved and simplified prefix numbering

• IPv6 allows for multiple addresses on a single interface

• IPv6 uses link-local addresses

• IPv6 negates the need for DHCP as an IPv6 device can auto assign itself a unique link-local address.

is IPv4 obselete?

No it is not currently it coexists with IPv6 but will be gradually replaced

how does IPv4 transition to IPv6?

• Dual Stack - both 4 and 6 are running at the same on an interface

• 6to4 - uses tunneling between the 2

• NAT protocol translation - between IPv6 and 4

how many bits are in a coloned hex?

16 bits

how would 09C0 look in a simpified hex digit and why?

‘9C0’ as leading 0s are allowed to be omitted

how would 0000 be written in an IPv6 example?

0

how would 0000:0000 be written in an IPv6 example?

::

how would FF01:0000:0000:0000:0000:1 be written in an IPv6 example?

FF01::1

What parts make up an IPv6 address?

• A subnet prefix which represents the network to which the interface is connected to

• An interface ID, sometimes called a local identifier or token

what is the IPv6 address - ::/0

the default static route

what is the IPv6 address - ::/128

usually assigned to a link-local address

what is the IPv6 address - ::1/128

address of the local host

what is the IPv6 address - FF00::/8

Multicast addresses

How do you enable IPv6 on a router?

ipv6 unicast-routing

Can a link-local address be created automatically

Yes it can only if IPv6 is enabled on an interface. It uses the EUI-64 format.

Is a prefix mask required on link-local addresses?

No because they are not routed

How does tunneling work in IPv6?

By encapsulating an IPv6 packet within IPv4

What is an advantage to NAT-PT

no modifications are required on the hosts