Novell LINUX ENTERPRISE DESKTOP 10 SP2 - DEPLOYMENT GUIDE 08-05-2008 Deployment Manual page 619

any intervention on the administrator's part and there is no need to maintain a central
server for address allocation—an additional advantage over IPv4, where automatic
address allocation requires a DHCP server.
Mobility
IPv6 makes it possible to assign several addresses to one network interface at the
same time. This allows users to access several networks easily, something that
could be compared with the international roaming services offered by mobile phone
companies: when you take your mobile phone abroad, the phone automatically
logs in to a foreign service as soon as it enters the corresponding area, so you can
be reached under the same number everywhere and are able to place an outgoing
call just like in your home area.
Secure Communication
With IPv4, network security is an add-on function. IPv6 includes IPsec as one of
its core features, allowing systems to communicate over a secure tunnel to avoid
eavesdropping by outsiders on the Internet.
Backward Compatibility
Realistically, it would be impossible to switch the entire Internet from IPv4 to IPv6
at one time. Therefore, it is crucial that both protocols are able to coexist not only
on the Internet, but also on one system. This is ensured by compatible addresses
(IPv4 addresses can easily be translated into IPv6 addresses) and through the use
of a number of tunnels. See
(page 608). Also, systems can rely on a dual stack IP technique to support both
protocols at the same time, meaning that they have two network stacks that are
completely separate, such that there is no interference between the two protocol
versions.
Custom Tailored Services through Multicasting
With IPv4, some services, such as SMB, need to broadcast their packets to all hosts
in the local network. IPv6 allows a much more fine-grained approach by enabling
servers to address hosts through multicasting—by addressing a number of hosts as
parts of a group (which is different from addressing all hosts through broadcasting
or each host individually through unicasting). Which hosts are addressed as a group
may depend on the concrete application. There are some predefined groups to ad-
dress all name servers (the all name servers multicast group), for example, or all
routers (the all routers multicast group).
Section 30.2.3, "Coexistence of IPv4 and IPv6"
Basic Networking 603