Michael Powell wrote: > > > > I have read some recommendations on combining a stateful firewall with > > divert, e.g. > > http://www.derkeiler.com/Mailing-Lists/FreeBSD-Security/2003-06/0078.html > > and http://nuclight.livejournal.com/124348.html (the latter is in > > Russian). > > > > Do I understand correctly that it is (mathematically?) impossible to > > use the two together without also using "skipto"?
[dd] > > I haven't used ipfw for a very long time, and haven't kept current with any > changes. Below is an example (using kernel pppd) that I used to use a long > time ago. For example purposes only, extract what you need for your specific > configuration needs. I have looked at your ruleset. First you have: [dd] > $fwcmd add divert natd ip from any to me in via ppp0 > $fwcmd add divert natd ip from 10.10.0.0/8 to any out via ppp0 > $fwcmd add check-state > [dd] and only later you have your keep-state rules: > > $fwcmd add allow udp from any to any via ppp0 keep-state > $fwcmd add allow log icmp from any to any icmptypes 3,4 > > $fwcmd add allow tcp from any to me 80 via ppp0 keep-state > > $fwcmd add deny log tcp from any to any in recv ppp0 setup > $fwcmd add allow tcp from any to any out xmit ppp0 setup keep-state > $fwcmd add allow tcp from any to any via ppp0 established keep-state This means your dynamic rules will contain an already NAT-ted address, which is useless. With my example ruleset below, where would you put the keep-state option? 00100 divert 8668 ip from any to table(1) out via rl0 00200 deny log logamount 100 ip from 10.0.0.0/8 to any out via rl0 00300 deny log logamount 100 ip from 172.16.0.0/12 to any out via rl0 00400 deny log logamount 100 ip from 192.168.0.0/16 to any out via rl0 00500 divert 8668 ip from table(1) to any in via rl0 00600 check-state 00700 deny log logamount 100 ip from any to 10.0.0.0/8 in via rl0 00800 deny log logamount 100 ip from any to 172.16.0.0/12 in via rl0 00900 deny log logamount 100 ip from any to 192.168.0.0/16 in via rl0 65535 allow ip from any to any -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN sip:suda...@sibptus.tomsk.ru _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"