IPv6 - já que tá todo mundo falando dele...

...Segue então uma breve introdução sobre IPv6 que fiz, numa abordagem mais técnica e resumida.
Mas tem uma surpresinha, como o CCNP, especificamente BSCI que cobra o assunto é em inglês, fiz o favor de ajudar quem está estudando. Não se preocupe, prepararei outras partes explicando mais afundo!

- IPv6 has the addresses 128 bit long, and can support 3.4 x 10^38 addresses!!!

- The header of IPv6 is much more simpler, even though it's bigger.

- There are three types of communications:

• unicast: pretty much what is in IPv4.
  
• multicast: one to many, but more intelligent in the way that you can define the scope of what is the boundary of the packet to reach, like an organization, a layer 2 domain only, and so on.
  
• anycast: multiple devices with the same address. The closest device will respond to the message, like a cluster of webmails where we could have many mirrors around the world for a big company for instance.
  

- There are also three types of addresses that most of the time will be configured in each device:

• link-local scope: this is the address automatically assigned for the layer 2 domain communication only. APIPA (Automatic Private IP Addressing) is the equivalent to IPv4.
  
  it's always gonna start with FE80 + 54 zero bits + MAC Address + FFFE in the middle of the MAC Address.
  
  
• unique-local scope: this is the address used in your organization, like the private addressing used in IPv4 before the NAT.
  
  starts with FD00 + Global ID (Company identifier) + Subnet ID (Same as IPv4) + Interface ID.
  
  
• global scope: this is used in the internet, a valid and routable address.
  
  starts with 001 bits always, and is used for the global routing prefix, like a continent, or country + 64 bits minus the global routing prefix for subnet id + 64 bits for interface id.

Comentários serão bem-vindos :)

Abraços!