2.5 – What is IPv6

Question 1

Format

Answer 1

• IPv6 Address = 8 [16 bit blocks] = 128
• NOT in decimal
• Written in Hex [0—9 & A—F] = 16 digits
  * Every digit = 4 binary bits

Question 2

IPv6 Address Example

Answer 2

2001:0db8:3c4d: 0012: 0000:0000:1234:56ab

1st 3 blocks = Global Routing Prefix [48 bits]
4th block = Subnet-ID [16 bits]
Prefix (1st 4 blocks) = [64 bits]

Last 4 blocks = Interface ID [64 bits]

Question 3

IPv6 Address Divided

Answer 3

• 128 bits divided into 8 fields
• Each being 16 bits
• [each digit = 4 bits, 4 x 4 = 16 bits for 1 block]

Question 4

IPv6 Prefix

Answer 4

1st 64 bits of an IPv6 address

• Assigned to an organization

Question 5

IPv6 Interface-ID

Answer 5

last 64 bits of an IPv6 address

• Used to ID a unique interface on a host

Question 6

Compressing IPv6 Address

Answer 6

2001:0db8:3c4d:0012:0000:0000:1234:56ab

• Drop the leading zeros in a field =
  * 2001:db8:3c4d:12:0000:0000:1234:56ab
• 4 zeros –> single zero
  * 2001:db8:3c4d:12:0:0:1234:56ab
• Drop groups of 4 zeros with (::) CAN ONLY APPEAR ONCE
  * 2001:db8:3c4d:12::1234:56ab

Question 7

Compressing Rule

Answer 7

only use double colon (::) ONCE because then you can know how many blocks of zeros you have