In fact, it's already happening.
Vint Cerf, Chief Internet Evangelist at Google, and a founding father of the Internet, discusses the next version of the Internet, IPv6, and why we need it.
IPv6 Addressing
The most obvious difference between IPv6 and IPv4 is address size. An IPv6 address is 128 bits long, which is four times larger than an IPv4 address.A 32-bit address space allows for
4,294,967,296
possible addresses.... 2**32
A 128-bit address space allows for 2**128 or
340,282,366,920,938,463,463,374,607,431,768,211,456
(or 3.4**1038) possible addresses.
128-bit address space provides 655,570,793,348,866,943,898,599 (6.5x1023) addresses for every square meter of the Earth’s surface.
The use of 128 bits allows for multiple levels of hierarchy and flexibility in designing hierarchical addressing and routing, which the IPv4-based Internet lacks.
RFC 3513 describes the IPv6 addressing architecture.
The following is an IPv6 address in binary form:
0011111111111110001010010000000011010000000001010000000000000000
0000001010101010000000001111111111111110001010001001110001011010
The 128-bit address is divided along 16-bit boundaries:
0011111111111110 0010100100000000 1101000000000101 0000000000000000 0000001010101010 0000000011111111 1111111000101000 1001110001011010
Each 16-bit block is converted to hexadecimal, and adjacent blocks are separated with colons. The result is:
3FFE:2900:D005:0000:02AA:00FF:FE28:9C5A
removing the leading zeros
3FFE:2900:D005:0:2AA:FF:FE28:9C5A
Table 3-4 lists decimal, hexadecimal, and binary equivalents of the numbers 0-15.
Decimal | Hexadecimal | Binary |
---|---|---|
0 | 0 | 0000 |
1 | 1 | 0001 |
2 | 2 | 0010 |
3 | 3 | 0011 |
4 | 4 | 0100 |
5 | 5 | 0101 |
6 | 6 | 0110 |
7 | 7 | 0111 |
8 | 8 | 1000 |
9 | 9 | 1001 |
10 | A | 1010 |
11 | B | 1011 |
12 | C | 1100 |
13 | D | 1101 |
14 | E | 1110 |
15 | F | 1111 |
Types of IPv6 Addresses
IPv6 has three types of addresses:
- Unicast
A unicast address identifies a single interface within the scope of the type of unicast address. With the appropriate unicast routing topology, packets addressed to a unicast address are delivered to a single interface. A unicast address is used for communication from one source to a single destination.
- Multicast
A multicast address identifies multiple interfaces. With the appropriate multicast routing topology, packets addressed to a multicast address are delivered to all interfaces that are identified by the address. A multicast address is used for communication from one source to many destinations, with delivery to multiple interfaces.
- Anycast
An anycast address identifies multiple interfaces. With the appropriate routing topology, packets addressed to an anycast address are delivered to a single interface, the nearest interface that the address identifies. The “nearest” interface is defined as being closest in terms of routing distance. An anycast address is used for communication from one source to one of multiple destinations, with delivery to a single interface.
IPv6 addresses always identify interfaces, not nodes. A node is identified by any unicast address assigned to one of its interfaces.
A unicast address identifies a single interface within the scope of the type of unicast address. With the appropriate unicast routing topology, packets addressed to a unicast address are delivered to a single interface. A unicast address is used for communication from one source to a single destination.
A multicast address identifies multiple interfaces. With the appropriate multicast routing topology, packets addressed to a multicast address are delivered to all interfaces that are identified by the address. A multicast address is used for communication from one source to many destinations, with delivery to multiple interfaces.
An anycast address identifies multiple interfaces. With the appropriate routing topology, packets addressed to an anycast address are delivered to a single interface, the nearest interface that the address identifies. The “nearest” interface is defined as being closest in terms of routing distance. An anycast address is used for communication from one source to one of multiple destinations, with delivery to a single interface.
The fields within the global unicast address as defined in RFC 3587 create a three-level structure, as Figure 3-9 shows.
Figure 3-9 The three-level structure of a global unicast address as defined in RFC 3587
The public topology is the collection of larger and smaller ISPs that provide access to the IPv6 Internet and the organizations that connect to the IPv6 Internet. The site topology is the collection of subnets within an organization’s site. The interface identifier identifies a specific interface on a subnet within an organization’s site.
Local-use unicast addresses fall into two categories:
- Link-local addresses are used between on-link neighbors and for Neighbor Discovery processes, which define how nodes on an IPv6 subnet interact with hosts and routers.
- Site-local addresses are used between nodes communicating with other nodes in the same site of an organization’s intranet.
Why is the internet running out of room?
Just as phones use a system of phone numbers in order to place calls, every Internet-connected device gets a unique number known as an "IP address" that connects it to the global online network.![IPv6 Graph](http://www.google.com/intl/en/ipv6/images/graph.png)
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