ICND1 - 12.Introducing IPv6 Flashcards

Questions and Answers

How many bits are in an IPv6 address?

128 bits

What are some additional benefits of IPv6 when compared to IPv4? (Select all that apply)

Flow labels (correct)

Simplified header (correct)

Limited multicast support

Security and mobility built in (correct)

What are the three types of IPv6 addresses?

Unicast, Anycast, Multicast

What is an IPv6 unicast address?

An address that identifies a single device. Signup and view all the answers

What is a global unicast address?

A unicast address that is globally unique and can be routed globally. Signup and view all the answers

What is a link-local unicast address?

An address confined to a single physical link. Signup and view all the answers

What is an IPv6 anycast address?

An address that represents a group of devices that support a similar service. Signup and view all the answers

What is an IPv6 multicast address?

An address that identifies a set of devices called a multicast group. Signup and view all the answers

What is the address used for the IPv6 loopback address?

0:0:0:0:0:0:0:1, expressed as ::1. Signup and view all the answers

What are the IPv6 addresses that are reserved by the IETF?

Approximately 1/256 of all the total IPv6 address space. Signup and view all the answers

What are the two rules for reducing the size of written IPv6 addresses?

Rule 1: Leading 0s do not have to be written; Rule 2: Consecutive fields of all 0s can be represented with a double colon. Signup and view all the answers

What is the EUI-64 standard?

A standard to stretch 802.3 MAC addresses from 48 to 64 bits. Signup and view all the answers

What are the three ways that an IPv6 host can be assigned an address?

Statically, with stateless autoconfiguration, or... Signup and view all the answers

Study Notes

IPv6 Address Basics

An IPv6 address is 128 bits long, represented in eight 16-bit hexadecimal segments (e.g., 2001:0D02:0000:0000:0000:C003:0001:F00D).

Advantages of IPv6 Over IPv4

Larger address space to accommodate more devices.
Simplified header structure.
Autoconfiguration feature for easier setup.
Enhanced multicast support.
Introduction of extension headers for added functions.
Flow labels for sophisticated data handling.
Built-in security and mobility features.
Improved address allocation methods.
Strict aggregation capabilities for better routing efficiency.

Types of IPv6 Addresses

Three main categories exist: Unicast, Anycast, and Multicast.

Unicast Address

A unicast address identifies a single device with one-to-one mapping.
Types include global, link-local, loopback (::1), and unspecified (::).

Global Unicast Address

Globally unique and routable across the internet.
Defined in RFC 4291 as part of the 2000::/3 address space administered by IANA.

Link-Local Unicast Address

Specific to a single physical link and not routable outside the subnet.
Typically begins with FE80 and may use the MAC address for interface identifier.
A device can hold multiple link-local and global addresses.

Anycast Address

Represents a group of devices offering similar services; each is assigned the same address.
Data is routed to the nearest node sharing the anycast address.
Configured by appending "anycast" to a global unicast address.

Multicast Address

Identifies multiple devices in a multicast group and facilitates one-to-many communication.
Replaces IPv4 broadcast addresses and starts with FF00::0/8.

Loopback Address

The IPv6 loopback address is 0:0:0:0:0:0:0:1, commonly abbreviated as ::1.

Reserved IPv6 Addresses by IETF

A small portion of the total IPv6 address space is reserved (1/256).
Includes subnet-router anycast addresses and subnet anycast addresses for the highest interface identifiers within a subnet.

Address Compression Rules

Rule 1: Omit leading zeros in any field (e.g., 2001:0D02:0:0:0:C003:1:F00D).
Rule 2: Replace one consecutive sequence of zero fields with a double colon (e.g., 2001:D02::C003:1:F00D).
The double colon can only be used once in an address.

EUI-64 Standard

Converts 48-bit MAC addresses to 64-bit identifiers by inserting 0xFFFE at the 24th bit and flipping the universal/local flag.
Allows hosts to auto-configure a unique IPv6 address without manual input or DHCP. For instance, MAC address 00-AA-11-17-FC-0F translates to IPv6 address 2001:0DB8:0:1:02AA:11FF:17FE:FC0F using EUI-64.

Address Assignment Methods

IPv6 hosts can receive addresses statically, through stateless autoconfiguration, or DHCP.

Description

Test your knowledge of IPv6 with these flashcards covering essential concepts, including the structure of IPv6 addresses and their advantages over IPv4. Perfect for networking students preparing for the ICND1 exam.