IPv6
IPv6 Addressing
IPv6 Addressing
- IPv6 address space is 128 bits (16 bytes)
- Large address space. Divided along 16-bit boundaries, converted to 4 digit hexadecimal numbers, separated by colons - known as colon hexadecimal .
- Simpler host configuration. IPv6 supports dynamic client configuration by using DHCPv6 and IPv6 also enables routers to configure hosts dynamically.
- Improved routing efficiency. Reduces how many routes the Internet must process by supporting hierarchical routing.
- Built-in security. IPv6 ensures all hosts encrypt data while in transit by including native IPSec support.
- IPv6 address types
- Unicast. Packets delivered to a unicast address are delivered to a single interface, one-to-one communication
- Multicast. Packets are delivered to multiple interfaces, one-to-many. One-to-many communication between computers that are defined as using the same multicast address. Multicast addresses have the first 8 bits set to 1111 1111 or FF
- Anycast. Identifies multiple interfaces, but delivered to a single interface, the closest one. Used for locating services or the nearest router.
- Global Unicast address
- Equivalent to IPv4 public addresses
- Identified by the FP (Format Prefix) of 001 (globally routable and reachable on the IPv6 Internet
- The scope of a global unicast address is the entire IPv6 Internet
- The address prefix of a currently assigned global address is 2000::/3
- The combination of the first 3 high-order fixed bits and the 45-bit Global Routing Prefix is a 48-bit prefix assigned to an individual site
- The next 16 bits are the Subnet ID
- The Interface ID field is the next 64-bits
