1. Address Assignment Features – Allows easier renumbering, dynamic allocation, and recovery of addresses
2. Aggregation – Blocks are easier to aggregate vs. IPv4
3. No Need for NAT/PAT
4. IPSec required – more secure
5. Header improvements – no need to recalculate Checksums – Flow label to easily identify packets belonging to same connection
6. Transition Tools –
Public IPv6 addresses are grouped by major geographical region.
Inside each region, the address space is further divided to ISPs in that region.
Each ISP in a region further divides their range to customers.
ICANN assigns one or more IPv6 address ranges to each RIR (Regional Internet Registry)
IPv6 uses 32 HEXADECIMAL numbers organized into 8 quartets that are separated by a : (colon).
Each hex digit represents 4 digits.
Leading 0s can be eliminated in a quartet.
One and only 1 string of consecutive 0s (even crossing quartets) can be represented with a :: (double colon).
IPv6 addresses use / (slash) notation for subnet masks.
Global Unicast – Same as IPv4 public addresses
Prefix 2000::/3 (Can be easily identified as it starts with a 2 or 3)
Unique Local – Private IP addresses
Prefix FD00::/8 (Can easily be identified as it starts with FD)
Link Local – For packets sent on a local subnet
Prefix: FE80::/10 (Easily identified as starting with FE8, FE9, FEA, and FEB)
Multicast – Multicasts that stay on local subnet
Prefix: FE2::/16 (Easily identified as it starts with FF02)
FF02::1 – All nodes on the link
FF02::2 – All routers on the link
FF02::12 – Used by hosts to send to a DHCPv6 inquiry
DHCPv6 servers can either be stateful or stateless.
The use of the zero-subnet or broadcast subnet is a non-issue with IPv6.