IPv6 Notes -Part1

- In IPv6, as in IPv4, unicast addresses have a two-level network:host hierarchy (known in IPv6 as the prefix and interface ID).

 ipv6 address types:

    Unicast :

• Aggregatable Global Addresses: 

begin with binary 001. This value can be written in prefix notation as 2000::/3, which means “all IPv6 addresses whose first 3 bits are equal to the first 3 bits of hex 2000.

• Link-Local Addresses:

begin with FE80::/10. The Interface ID portion of the address is derived using the modified EUI-64 format .

     Multicast :

IPv6 always begin with FF as the first octet in the address, or FF00::/8. The
second octet specifies the lifetime and scope of the multicast group. Lifetime can be permanent or
temporary. Scope can be local to any of the following:
■ Node
■ Link
■ Site
■ Organization
■ Global

IPv6 multicast uses a solicited-node group that each router must join for all of its unicast and anycast addresses. The format for solicited-node multicast addresses is FF02::1:FF00:0000/104 ,
Solicited-node addresses are used in the Neighbor Discovery (ND) process

   AnyCast :
Once an address is assigned to more than one host, it becomes an anycast address by definition. Because anycast addresses cannot be used to source traffic, however, a router must know if one of its interface IPv6 addresses is an anycast address. Therefore, Cisco IOS Software requires the anycast keyword to be applied when an anycast address is configured, as in this example:
Mariano(config-if)# ipv6 address 3001:fffe::104/64 anycast