This article is a quick reference guide for ipv6 characteristics.

-ipv4 32 bits
-ipv6 uses 128 bits

ipv4 dotted decimal
-1.2.3.4
-each place denotes 1 byte

ipv6
-xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxxx:xxxxx (16×8 =128)
-Two characters = one byte
-First 64 network last 64 host

-Aggregatble Global Unicast addresses
2000… to 3fff… (2001 as of now)

-Site-local Unicast addresses (Private addressing)
FEC0…

-Link-local Unicast addresses
FE80…

-Multicast addresses
FF…

-ipv6 unicast routing
under the interface :
-ipv6 enable
-ipv6 address 2001::1/64 (for example)
for example
ipv6 address 2001:35::3/64
network portion of the address is : 2001:0035:0000:0000
host portion is : 0000:0000:0000:0003

If we were to get a /48 subnet from our provider and we want to make /64 subnets we distract 64 - 48 = 16, 2 to the power 16 = 65535 subnets