Question

The device just joined the network, of which network address is 2000:152E:C531/48. If the device is in the subnet 1185 and its IEEE physical address is 0D-09-E1-D2-A0-5F, what is the IPv6 address this device can use ?

Answer 1

Description:

IPv6 address is broken down into 3 parts, the Network Address, the Subnet Address, and the Device Address.

The Network Address is the first 48-bits of the address, or since they are grouped in 16-bit groupings, effectively the first 3 groups of numbers designate the network.  

2000:152E:C531

The Subnet Address is the next 16-bits of the address, or as addresses are grouped in 16-bit groupings.

1185

Network Address and the Subnet Address, and that’ll give this address a specific designation of the Network that this device is on, and the Subnet that this device is one.

Device address or MAC address is converted into Ipv6 address by following steps

0D-09-E1-D2-A0-5F

Step 1: Add 0xFF:FE in middle to make it 64 bits OF MAC Address

0D-09-E1-FF-FE-D2-A0-5F

Step 2:

Pair the bits together

0D09-E1FF-FED2-A05F

Step 3: Flip 7th bit of the first part, i.e

0D09 = 0000110100001001

Flip 7th bit makes it  0000111100001001 => 0F09

Address becomes: 2000:152E:C531:1185:0F09:E1FF:FED2:A05F/64