IPv6 configuration on Linux box

[zhang zhishou]

Hi,

I am a IPv6 newbie. I have managed to add the ipv6-in-ipv4 interface
(sit0) in my linux box.
When I try to ping local machine using "ping -a inet6 ::1", or "ping -a
inet6 ::127.0.0.1", or "ping -a inet6 ::192.168.133.24"
(::192.168.133.24 is the ipv4-compatible ipv6 address of my linux box),
the following is what I get :

ping: icmp6:    unkown protocol
ping: ::1:    No IP version 4 or IP version 6 addresses available.

Anybody could tell me how to solve the problem?
Thanks!!!