1)  On systems running Upstart, shorewall-init cannot reliably secure
    the firewall before interfaces are brought up.

2)  The 'enable', 'reenable' and 'disable' commands do not work
    correctly in configurations with USE_DEFAULT_RT=No and optional
    providers listed in the DUPLICATE column.

3)  When running Shorewall 5 on older distributions, such as Centos 6,
    Shorewall ipset creation will fail with an error similar to the
    following:

      WARNING: ipset lvpn does not exist; creating it as an hash:net set
      ipset v6.11: Unknown argument: `counters' Try `ipset help' for
      more information.

    Workaround: Create the ipset yourself.

       ipset create <name> hash:net family inet timeout 0

    Corrected in Shorewall 5.0.13.1.
