1)  On systems running Upstart, Shorewall-init cannot reliably close
    the firewall before interfaces come up.

2)  Under rare circumstances where COMMENT is used to attach comments
    to rules, OPTIMIZE 8 through 15 can result in invalid
    iptables-restore (ip6tables-restore) input.

    Workaround: Don't use optimizaiton levels greater than 7.

3)  Under rare circumstances unvolving exclusion, OPTIMIZE 8 through 15
    canresult in invalid iptables-restore (ip6tables-restore) input.

    Workaround: Don't use optimizaiton levels greater than 7.