
Chapter 20
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IPv6 Transition Planning and Strategies 327
With native IPv6 connectivity and continuing IPv4 support, an organiza-
tion would have direct connectivity for both IP protocols.
20.2 IPv6 Tunneling
As of 2003, most commercial ISPs claiming to offer IPv6 connectivity still
do not offer native IPv6 connectivity, so for networks where such service is
not available, tunneling offers a next best choice. Tunneling allows isolated
IPv6 networks or IPv6 end nodes to communicate with other IPv6 nodes
across the IPv4 Internet. There are different types of tunneling, including
configured and automatic, but they all work in the same basic way as any
tunneling ...