You need to allow the 6to4 tunnel traffic from the Bering-uClibc Firewall to the tunnelbroker freenet6.org. This traffic uses IP protocol 41.

With Shorewall 1.4.3 and later you can add a 6to4 tunnel definition in the /etc/shorewall/tunnels file. In the examples below it is assumed that your firewall zone is called "fw" and the Internet zone "net". The gateway address in 6to4tunnel is your tunnel end-point at freenet6.org.

#TYPE    ZONE   GATEWAY        GATEWAY ZONE 
(...)
6to4     net    206.123.31.115
(...)

More information on Shorewall and 6to4 tunnels can be found in the Shorewall documentation.

Additionally you have to open port 3653 for tspc used with freent6.org in /etc/shorewall/rules:

# tspc  - tunnel setup protocol
ACCEPT        fw        net:206.123.31.115           tcp      3653
ACCEPT        net:206.123.31.115      fw            tcp      3653

Add the tunnel interface to 6wall /etc/6wall/interfaces6:

#ZONE   INTERFACE       OPTIONS
#
net     tunFN           nositelocal
loc     eth1
#

For more information about 6wall please look at:

http://leaf.sourceforge.net/devel/dorus/sixwall.html

freenet6 is supposed to take care of configuring radvd by writing radvd.conf for you and restarting radvd automatically. Andreas Rottmann, the Debian maintainer of radvd, decided that it should not let freenet6 rewrite the entire radvd configuration file lest manual modifications by the administrator be overwritten. He asked if it would be possible to have a way for freenet6 to change the advertised prefix of radvd without rewriting the whole config file. But Nathan Lutchansky (radvd programmer) answered in substance that administrators, who do not want to risk their modifications overwritten should handle radvd.conf manually. In typical Debian fashion Andreas Rottman probably believes he is better safe than sorry, and so he commented out the parts of /etc/freenet6/setup.sh that deal with rewriting radvd.conf - and we decided to follow his approach - just to be on the safe side as well.

If you think you have an easy-to-use setup you can uncomment the section in /etc/freenet6/setup.sh shown in the screenshot below - at least we saw no problems with that automatic rewriting and restart of radvd in a freenet6 only setup.

#   Display 1 "Create new $rtadvdconfigfile"
#   echo "##### rtadvd.conf made by TSP ####" > "$rtadvdconfigfile"
#   echo "interface $TSP_HOME_INTERFACE" >> "$rtadvdconfigfile"
#   echo "{" >> "$rtadvdconfigfile"
#   echo " AdvSendAdvert on;" >> "$rtadvdconfigfile"
#   echo " prefix $TSP_PREFIX:0001::/64" >> "$rtadvdconfigfile"
#   echo " {" >> "$rtadvdconfigfile"
#   echo " AdvOnLink on;" >> "$rtadvdconfigfile"
#   echo " AdvAutonomous on;" >> "$rtadvdconfigfile"
#   echo " };" >> "$rtadvdconfigfile"
#   echo "};" >> "$rtadvdconfigfile"
#   echo "" >> "$rtadvdconfigfile"
#   /etc/init.d/radvd stop
#   if [ -f $rtadvdconfigfile ]; then
#      KillProcess $rtadvdconfigfile
#      Exec $rtadvd -C $rtadvdconfigfile
#      Display 1 "Starting radvd: $rtadvd -C $rtadvdconfigfile"
#   else
#      echo "Error : file $rtadvdconfigfile not found"
#      exit 1
#   fi

For a manual configuration of radvd you need to know the subnet assigned to you by freenet6. After you have configured freenet6 and rebooted you'll find the assigned subnet with:

# ip -6 addr show | grep 3ffe

The result will look like:

inet6 3ffe:bc0:b40:1::1/64 scope global
inet6 3ffe:bc0:8000::3497/128 scope global

The first line must be added to radvd.conf as prefix - like here:

interface eth1
{
   AdvSendAdvert on;
   prefix 3ffe:0bc0:0b40:0001::/64

   {
        AdvOnLink on;
        AdvAutonomous on;
   };
};

Save radvd.lrp and restart /etc/init.d/radvd.