Lesson 4 - Chapter 3: Network Addressing With IPv6

Question 1

How many bits are IPv6 addresses?

Answer 1

128-bits (compared to 32-bits for IPv4)

Question 2

Where IPv4 addresses are converted to decimal for humans to remember better, IPv6 is converted to what?

Answer 2

Hexadecimal

Question 3

An IPv4 address has 4 segments. How many does an IPv6 have?

Answer 3

8

Question 4

What’s the difference in how the decimal/hexadecimal numbers are separated in IPv4 and IPv6 addresses?

Answer 4

IPv4 = dots (periods)
IPv6 = colons

Question 5

Are IPv6 addresses case-sensitive?

Answer 5

No

Question 6

To shorten an IPv6 address, what do you do with the 0’s?

Answer 6

Leading zeros = omitted from a group(replaced with ::) or shrunk down to one 0

Examples
00CF = CF
0000 = 0

Question 7

To shorten an IPv6 address, what can you do with all-zero groups 0000?

Answer 7

You can omit them and indicate them by placing 2 colons in their place

Example
2001:0000:0000:3210:0800:200C:00CF:1234
0000:0000:0000:0000:0000:0000:0000:0001/128

Becomes
2001::3210:800:200C:CF:1234
0:0:0:0:0:0:0:1 or ::1/128

Question 8

What bits of an IPv6 address are for the host ID?

Answer 8

the last 64 bits

Question 9

What is the Extended Unique Identifer-64-bit? (EUI-64)

Answer 9

the host ID that Linux and macOS build from the MAC address of the NIC

Question 10

How does Windows generate the host ID of an IPv6 address? Does it ever change?

Answer 10

it generates a random value when a NIC is configured

(that number never changes)

Question 11

What’s the abbreviated loopback address for IPv6?

Answer 11

0:0:0:0:0:0:0:1 or ::1/128

(entirely a host address, no network address)

Question 12

Since IPv6 doesn’t have a subnet mask, what does it use that’s similar?

Answer 12

a prefix length

Question 13

What’s a prefix length? What does it control?

Answer 13

controls how many address bits define the network (and the rest define the host address)

Question 14

What’s the default prefix length?

Answer 14

64 bits written as /64

(so IPv6 128 bits is divided equally)

Question 15

Name the 4 parts of an IPv6 address

Answer 15

1. Global prefix
2. Network prefix
3. Subnet ID
4. Interface ID

Question 16

Describe the 4 parts of an IPv6 address

Answer 16

1. Global prefix (first 4 digits)
2. Network prefix (first 16 digits + global prefix)
3. Subnet ID (last 2 digits of Network prefix)
4. Interface ID (17th-32nd digits)

Question 17

With IPv6, a single network card will have multiple….?

Answer 17

IP addresses

Question 18

What’s a link-local address?

Answer 18

the IPv6 address a computer gives itself when it first boots up (will always have this address, does not indicate a connection issue)

(similar to IPv4’s APIPA local address)

Question 19

The first 64 bits of a link-local IPv6 address are?

Answer 19

fe80::/10
(fe80:0000:0000:0000)

Question 20

The remaining 64 bits of an IPv6 address is the?

Answer 20

Interface ID (equivalent to IPv4 Host ID)

Question 21

Link-local addressing does all the local networking hard work so that you don’t need to mess with what 2 things?

Answer 21

static and DHCP addressing unless you have dedicated servers

Question 22

To use the Internet with IPv6, what does a system need?

Answer 22

a 2nd IPv6 address called a global unicast address (also called global address)

Question 23

What is a global unicast address also called?

Answer 23

global address (and it’s the 2nd IPv6 address needed to access the Internet)

Question 24

How do you get a global address?

Answer 24

Most common is to request it from the default gateway router (as long as it’s configured to give out global IPv6 addresses)

Question 25

What is a router solicitation (RS) message? What does it look for?

Answer 25

it’s a special packet sent out by a computer that was just plugged into a network to look for a router

Question 26

What does a router do with a router solicitation (RS) message?

Answer 26

it responds with a router advertisement (RA)

Question 27

What does a router advertisement (RA) do?

Answer 27

tells the computer that sent the RS its new network ID and subnet (together called the prefix) and DNS server if configured

Question 28

What defines the “prefix” that a router sends out in a router advertisement (RA)?

Answer 28

it tells systems their network ID and subnet

Question 29

What address does a router solicitation (RS) message use?

Answer 29

FF02::2

Question 30

What computers read the address used for RS messages?

Answer 30

the only computers that read that address are computers running IPv6 in the network

Question 31

The address that an RS message uses is called a..?

Answer 31

multicast address (not similar to a broadcast address, there’s no broadcast in IPv6)

Question 32

What happens when a computer’s RS message is answered by the router and it gets its prefix?

Answer 32

it generates the rest of the address and ends up with a 128-bit public IPv6 address and a link-local address

Question 33

Is this process the same in all 3 OS?

Answer 33

Yes

Question 34

How is using a global address different from IPv4 addresses?

Answer 34

A global address sends you straight to the Internet, doesn’t rely on the router translating from local address to a network one

Question 35

What’s a word of caution to keep in mind with computers that are running IPv6 and also have global addresses?

Answer 35

they can access your system unless you have a firewall (because data no longer needs to be routed through the router)

Question 36

Instead of using a ___ ___ IPv6 addresses use a ___ ___ to indicate the divider between the network ID and host ID

Answer 36

instead of using a subnet mask, IPv6 addresses use a prefix length

Question 37

Each host using IPv6 has a ___ ___ ___ that it generates itself

Answer 37

link-local address

Question 38

To get on the Internet, each host uses what from the default gateway router?

Answer 38

the host uses a global unicast address from the default gateway router

Question 39

What’s the range of hexadecimal numbers?

Answer 39

0-9
A-F