In JUNOS 9.6, a statement under [security] section could bring the J-series box back to pure packet-based mode. Actually that is a side effect of another statement, but it is a good side effect, from this point of view. Which is a statement that make MPLS family to be run under packet-mode, and the side effect is to bring inet family also into packet-mode.
Under this mode, all other security policy (under [security] section) is no longer available, but stateless firewall filter works well (under [firewall] section.)
The configuration is,
[edit]There do have other side effects that IPsec VPN is no longer avalible, because IPsec VPN in 9.6 is flow-based.
delete security
set security forwarding-options family mpls mode packet-based