help: enable NFS protocol connection tracking helper 

create:expression: "touch /tmp/vyatta-conntrack-sync"

end: if [ ${COMMIT_ACTION} = 'DELETE' ]; then
       echo "sudo iptables -D VYATTA_CT_HELPER -t raw -p tcp --dport 2049 -j CT --helper nfs"
     else
       echo "sudo iptables -I VYATTA_CT_HELPER -t raw -p tcp --dport 2049 -j CT --helper nfs"
     fi;
