connecting ipv6 nodes throu' ipv4 network ....

Hi,

I have two Linux nodes( hosts ) enabled with IPv6.

IPv6 addr of machine-1 is 3ff3:1234::1
IPv6 addr of machine-2 is 3ff3:1234::2

My LAN is based on IPv4.
To make these IPv6-hosts to communicate on the LAN, what
configuration do i need to make ???

I tried connecting only these two machines using a cross cable and 
sending IPv6 packets. But it failed. Is it correct to do so ???
thanx in advance.

-San
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