To use re6st in your crouton chroot environment, the following is required to modify the firewall settings
# Make sure to not use internet provider ipv6 (to
# use only re6stnet one, and to avoid shill resetting ipv6 settings)
sysctl net.ipv6.conf.wlan0.accept_ra=0
# accept ports needed for re6stnet
ip6tables -P FORWARD ACCEPT
ip6tables -A OUTPUT -p udp --dport 6696 -j ACCEPT
ip6tables -A OUTPUT -p udp --dport 326 -j ACCEPT
ip6tables -A INPUT -p udp --dport 6696 -j ACCEPT
ip6tables -A INPUT -p udp --dport 326 -j ACCEPT
# Accept ports needed for running any webrunner
ip6tables -A INPUT -p tcp --dport 9684 -j ACCEPT
ip6tables -A INPUT -p tcp --dport 50005 -j ACCEPT
# stop shill so that we can start it later with our
# own options
stop shill
# then start shill ourself by specifying the list of
# interfaces to ignore
shill --device-black-list=re6stnet-tcp,re6stnet10,re6stnet9,re6stnet8,re6stnet7,re6stnet6,re6stnet5,re6stnet4,re6stnet3,re6stnet2,re6stnet1,tun0,tun1,tun2,br0