Zte ZXR10 T1200, Руководство пользователя

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C h a p t e r
9
IPv6 Tunnel
Configuration
Table of Contents
IPv6 Tunnel Overview.........................................................65
Configuring IPv6 Tunnel .....................................................68
Configuring IPv6 Tunnel Maintenance and Diagnosis ...............69
IPv6 Tunnel Configuration Example ......................................69
IPv6 Tunnel Overview
It is impossible that IPv6 replaces IPv4 totally and immediately.
Therefore, they exist simultaneously in the same environment for
quite a long time. A good transition mechanism is needed to pro-
vide a stable transition and minimize the effects on the existing
users.
At present, this topic is the main target of IETF ngtrans work group.
Many transition mechanisms have been put forward and some of
them have been used for 6Bone. IETF recommends some transi-
tion mechanisms, such as tunnel technology, Dual Stack and Net-
work Address Translation (NAT) technology.
IPv6 Tunnel Technology
Tunnel technology is the primary way for communications between
IPv6 single subnets during the transition period. This mechanism
connects the isolated IPv6 node islands over the IPv4 network sea.
At the same time, if IPv6 becomes dominant in the future, it will
server as connections among the IPv4 islands.
The core concept of the tunnel technology is to make the existing
IPv4 network become the carrier for establishment of the IPv6
communications by encapsulating the IPv6 datagram into the IPv4
datagram. The datagram transmission between nodes at the two
ends of a tunnel is implemented through the IPv4 mechanism,
where the tunnel is treated as a directly connected channel.
In short, the idea of the tunnel policy is to encapsulate the IPv6
datagram into the IPv4 by a router.
The protocol field of the
IPv4 datagram header is set as 41, which indicats the net load
of this sub-group is an IPv6 sub-group. The source address and
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