IPV6 Addressing and Sub-netting

                                                              IPv6 Addressing and Sub-netting

An IPv6 address is 16 octets (128 bits).
It is difficult to foresee running out of IPv6 addresses.
Address consists of Hexadecimal values of eight 16 bit fields.

•  X:X:X:X:X:X:X:X (X=16 bit number, ex: A2FE)
•  16 bit number is converted to a 4 digit hexadecimal number.

Null value can be replaced by using ::

•  4EED:0023:0000:0000:0000:036E:1250:2B00
• →4EED:23:0:0:0:36E:1250:2B00
• →4EED:23::36E:1250:2B00
IETF recomendation of how to do the allocation.

Time For IPv6 subnetting....

When you do IPv6 sub-netting, you need to think in binary values not in hexadecimal values.

•  2001:1::/32
2001:0001::/32
Hex 2001 = Binary 0010 0000 0000 0001
Hex 0001 = Binary 0000 0000 0000 0001

•  2001:2:3::/48
2001:0002:0003::/48
Hex 2001 = Binary 0010 0000 0000 0001
Hex 0002 = Binary 0000 0000 0000 0010
Hex 0003 = Binary 0000 0000 0000 0011
Lets subnet /48 in to /64's

/64s in 2001:2:3::/48 are

– 2001:0002:0003:0001::/64
– 2001:0002:0003:0002::/64
– 2001:0002:0003:0003::/64
– Etc.

– 16 bits of address space

•  You can have 65536 /64s in one /48 IPv6 address.
•  Note:: indicates the remaining 64 bits are all zeros and can then be used to identify hosts::

How about /47s in 2001:1::/32? Please feel free to do the calculation and send me the results..