has been around for quite sometime now. A detailed look at
the underlining technology and the potential it holds. by
is the "next generation" Internet protocol developed by the
IETF, and is a natural increment to IPv4
offers security features at the router level of the TCP/IP
architecture, where they can benefit all TCP/IP applications
Internet has experienced a phenomenal growth in a short span
with more than 450 million users connected to it worldwide.
With the Internet penetrating each and every home and office,
the number of users hooked on to the Net is expected to reach
950 million by 2005. This growth has exposed limitations of
the currently used protocol for the Internet, IPv4 (Internet
Protocol Version 4). The main drawback is the dearth of IPv4
addresses. To overcome this limitation, IETF (Internet Engineering
Task Force) began working on the next-generation protocol
called IPv6 (Internet Protocol Version 6).
Problems with IPv4
main bottleneck with IPv4 is the shortage of IPv4 addresses.
IPv4 being 32-bit, it allows more than 4 billion addresses.
But with the massive growth in Internet usage, this pool of
addresses has started drying up. The other drawback of IPv4
is the destruction of end-to-end communication by Network
Address Translator (NAT) which was introduced to ease the
shortage of addresses. This makes application development
less practical. The final problem with IPv4 is that with more
users connecting to the Internet, the routing information
that the routers need to remember is also on the rise. This
could be a fatal problem for a router with little capacity.
What is IPv6?
is the "next-generation" Internet protocol developed
by the IETF, and is a natural increment to IPv4. IPv6 makes
use of 128-bit addresses instead of 32-bit. This provides
an estimated 340 undecillion (cardinal number equal to 1036)
IP addresses, one for every living thing on this planet. IPv6
is scalable and offers security in term of encryption of packets
and authentication of the sender. It also has built in plug-n-play
in terms of automatically configuring devices and networks.
IPv6 can be installed as a normal software upgrade in Internet
devices and is interoperable with the current IPv4. IPv6 runs
well on high performance networks (e.g. ATM, Gigabit Ethernet,
etc.) and on low bandwidth networks (e.g. wireless).
of the best improvements of IPv6 over IPv4 is auto configuration.
One approach of IPv6 will be to offer a "stateful"
auto configuration, which is similar to that of the DHCP (Dynamic
Host Configuration Protocol). This will allow servers to dynamically
assign unique addresses to computers as they request them,
drawing from a database of pre-allocated values. The other
approach is "stateless" auto configuration. Here
an IPv6 node creates a unique IP address by combining its
LAN MAC (Medium Access Control) address with a prefix provided
by the network router.
was optional in IPv4, whereas in IPv6 it has been made mandatory.
IPv6 offers security features at the router level of the TCP/IP
architecture, where they can benefit all TCP/IP applications.
IPv6 provides security encryption, authentication and data
integrity safeguards essential for any organization. The IPv6
authentication header extension guarantees that the recipient
receives a packet that is truly from its source address and
also provides end-to-end encryption at the network layer.
With IPv6, IPsec support is mandatory. By mandating IPsec,
a secure IP communication is available whenever you talk to
Multicast has been made mandatory in IPv6, which was optional
in IPv4. Multicast is beneficial for streaming technologies.
IPv6's new multicast address format allows for trillions of
possible multicast group codes, each identifying two or more
packet recipients. IPv6 also initiates a new kind of addressing
called anycast address. An anycast address enables a source
to specify that it wants to contact any one node from a group
of nodes via a single address. A packet with such an address
will be routed to the nearest interface in the group, according
to the router's measure of distance.
Quality of Service:
IPv6 has two "Quality of Service" features: flow
labels and priority. A flow is a sequence of packets sent
from a unicast source to a unicast or multicast destination.
The IPv6 flow label enables the flow's source to identify
a logical sequence of packets; intervening routers that support
this feature can then maintain a context for the flows currently
in transit, thus opening the door for possible optimized performance
and congestion management. Hosts can also specify a packet
priority, a feature that will allow IPv6 routers to discriminate
and favorably accommodate TCP/IP applications that require
faster response time.
These days we all would love to be connected to the Internet
while we are on the move. To make this possible, we would
require a mobile IP. IP mobility under IPv4 required additional
infrastructure as it requires informing any agent in the routing
process about a new location. Mobile IP via IPv6 requires
no such infrastructure
as it eliminates triangular routing and instead implements
a transitory second address. It defines
a multilevel global routing infrastructure.
order to protect huge investments in TCP/IP, backward compatibility
is ensured with transition mechanisms for communicating with
IPv4-based networks. IPv6 can indefinitely exist with IPv4
in both routers and host computers. IPv6 is designed to work
concurrently with IPv4, which will continue
to support existing TCP/IP applications. IPv6 can run
on the same machine concurrently with IPv4. As IPv6 implementations
become available, systems managers and network administrators
need upgrade only as many devices at a time as they can handle.
While the IPv4-to-IPv6 details for any particular device will
depend on the vendor's implementation, the migration will
depend on key characteristics of IPv6 architecture.
Rathod can be reached at firstname.lastname@example.org