IPv6 - Special Addresses
Version 6 has slightly complex structure of IP address than that of IPv4. IPv6 has reserved few addresses and address notations for special purposes. See the table below:
As shown in the table above 0:0:0:0:0:0:0:0/128 address does not specify to anything and is said to be an unspecified address. After simplifying, all 0s are compacted to ::/128.
In IPv4, address 0.0.0.0 with netmask 0.0.0.0 represents default route. The same concept is also applie to IPv6, address 0:0:0:0:0:0:0:0 with netmask all 0s represents default route. After applying IPv6 simplying rule this address is compressed to ::/0.
Loopback addresses in IPv4 are represented by 127.0.0.1 to 127.255.255.255 series. But in IPv6, only 0:0:0:0:0:0:0:1/128 address represents Loopback address. After simplying loopback address, it can be represented as ::1/128.
Reserved Multicast Address for Routing Protocols:
The above table shows reserved multicast addresses used by interior routing protocol.
All addresses are reserved in similar IPv4 fashion
Reserved Multicast Address for Routers/Node:
These addresses helps routers and hosts to speak to available routers and hosts on a segment without being configured with an IPv6 address. Hosts use EUI-64 based auto-configuration to self-configure an IPv6 address and then speaks to available hosts/routers on the segment by means of these addresses.