Subject: RFC2473: Why is the tunnel unidirectional

From: Mukesh Gupta <[email-masked]>
Date: Tue, 20 Aug 2002 09:51:58 -0700

Hi All,

I am not able to understand why the IPv6 tunnel is a unidirectional
mechanism as specified in section 3 of RFC 2473. Here is the text which
is not making sense to me.

===
An IPv6 tunnel is a unidirectional mechanism - tunnel packet flow takes
place in one direction between the IPv6 tunnel entry-point and
exit-point nodes (see Fig.1).

<snip>

Bi-directional tunneling is achieved by merging two unidirectional
mechanisms, that is, configuring two tunnels, each in opposite
direction to the other - the entry-point node of one tunnel is the
exit-point node of the other tunnel (see Fig.2).
===

Does it mean that we will have to configure 2 tunnels on each end point
in order to create a virtual point to point link between the two
systems. That's not the case for GRE for IPv4.

Help would be highly appreciated.

regards
Mukesh

--
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It is a mistake to look too far ahead.Only one link in the chain of destiny can be handled at a time.
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Mukesh Gupta
Phone: (650) 625-2264
Cell : (650) 868-9111
http://www.iprg.nokia.com/~mgupta
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