Question

I’m having a little trouble understanding the System.Net.IPAddress class, because I don’t know where to look for a definition of what some of the properties are referring to. Specifically, what are:

 IPAddress.IsIPv6LinkLocal
 IPAddress.IsIPv6Multicast
 IPAddress.IsIPv6SiteLocal
 IPAddress.IsIPv6Teredo

I will also happily accept an answer that points to a resource that explains these concepts. The MSDN site has proved insufficient.

Answer 1

IPAddress.IsIPv6LinkLocal

A link-local address is an IP address
that is intended only for
communications within the local
subnetwork. Routers do not forward
packets with link-local addresses.

IPAddress.IsIPv6Multicast

A multicast address is a logical
identifier for a group of hosts in a
computer network, that are available
to process datagrams or frames
intended to be multicast for a
designated network service. Multicast
addressing can be used in the Link
Layer (Layer 2 in the OSI model), such
as Ethernet multicast, and at the
Internet Layer (Layer 3 for OSI) for
Internet Protocol Version 4 (IPv4) or
Version 6 (IPv6) multicast.

IPAddress.IsIPv6SiteLocal

A unique local address (ULA) is an
IPv6 address in the block fc00::/7,
defined in RFC 4193. It is the IPv6
counterpart of the IPv4 private
address. Unique local addresses are
available for use in private networks,
e.g. inside a single site or
organisation, or spanning a limited
number of sites or organisations. They
are not routable in the global IPv6
Internet.

IPAddress.IsIPv6Teredo

In computer networking, Teredo is a
transition technology that gives full
IPv6 connectivity for IPv6-capable
hosts which are on the IPv4 Internet
but which have no direct native
connection to an IPv6 network.
Compared to other similar protocols
its distinguishing feature is that it
is able to perform its function even
from behind network address
translation (NAT) devices such as home
routers.