On Wed, Mar 26, 2008 at 3:53 AM, Jeremy Chadwick <[EMAIL PROTECTED]> wrote:
> I'll try to explain it with a very small ruleset and a couple scenarios: > > $ext_if = network interface that's got a public IP address > 4.4.4.4 = our public IP address > > pass out quick all flags S/SA keep state > pass out quick all > block in log all > pass in quick on $ext_if inet proto tcp from any to 4.4.4.4 port ssh > > Two scenarios: > > 1) When an incoming TCP packet from <any> to 4.4.4.4 on port 22 is seen, > that incoming packet is permitted (rule #4). Outbound responses from > 4.4.4.4 to <whoever sent the original incoming packet> are also > permitted (rule #1). Note the "keep state". > > > Correct me if I'm wrong, but I think the outbound packet will be matched against the #2 rule, as the rule #1 has "flags S/SA" and will not match the packet since the packet would have "ACK" flag set. Thus, the state will not be created in state table. That is if the rule #4 doesn't include "keep state" (which is default in RELENG_7). _______________________________________________ freebsd-pf@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-pf To unsubscribe, send any mail to "[EMAIL PROTECTED]"
