05-02-2013, 02:17 PM
IPv6 Addressing
IPv6 Addressing.ppt (Size: 236 KB / Downloads: 26)
Why IPv6?
Shortage of IPv4 addresses
Internet is expanding very rapidly in developing countries like India, China.
Heavy demand for IP addresses
End-to-End Reachability is not possible without IPv6
New Features like Autoconfiguration, better support for QoS, and Security, Route Aggregation
IPv6 Prefixes
Prefix is the part of the address where the bits have fixed values or are the bits of a route or subnet identifier
IPv6 subnets or routes always uses address/prefix-length notation
Examples:
21DA3::/48 for a route
21DA3:0:2F3B::/64 for a subnet
IPv6 Address Types
Unicast
Address is for a single interface.
One-to-one delivery to single interface
Multicast
One-to-many delivery to all interfaces in the set
Anycast
One-to-nearest (allocated from unicast address space).
Multiple devices share the same address.
All anycast nodes should provide uniform service.
Source devices send packets to anycast address.
Routers decide on closest device to reach that destination.
Suitable for load balancing and content delivery services.
IPv6 Address Representation EUI 64
IPv6 uses the extended universal identifier (EUI)-64 format to do stateless autoconfiguration.
This format expands the 48-bit MAC address to 64 bits by inserting “FFFE” into the middle 16 bits.
To make sure that the chosen address is from a unique Ethernet MAC address, the universal/local (U/L bit) is set to 1 for global scope (0 for local scope).