Date: Tue, 11 Apr 2006 21:51:05 -0700 From: Chris Telting <cdtelting-ml@comcast.net> To: freebsd-pf@freebsd.org Subject: Nat interfering with filtering rules Message-ID: <443C8739.6060507@comcast.net>
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Hello everyone, pf newbie here. I've been playing with rules for a day and I can't seem to wrap my head around what I'm suppose to do. First off I believe in "block all" and want an explicit opt in system. Nat is kind of getting in the way. pf.conf ------------- int_if="em0" ext_if="rl0" int_net="192.168.2.0/24" # Nat supposedly wants to be at he top of the list nat on $ext_if from $int_if:network to any -> ($ext_if) # Block everything, all rules are eqplicitly opt in block log all # Allow all local trafic on local network pass in on $int_if from $int_if:network to any pass out on $int_if from $int_if:network to any # Pass out to internet all local network trafic and keep state to allow connect pass out on $ext_if from $int_if:network to any keep state #pass from any to any This doesn't work because the packet IP address has already tanslated before the filter could get to it on $ext_if. If I change the rule to "from $ext_if" I can't distinguish between packets origionating on the local network verses the gateway/server. And if I do so anyway even if I specify "keep state" the returning packets don't get through from their external IP addresses. Only if I declare explicit pass in rules from specific ip addreses will I get return trafic. Is there anyway to do with without using a blanket "from any to any"? My first line of defence is identifiing the trafic source. Can I possiably change the priority of Nat so that it is the last action processed? Of course after I get it working I'll add port spefic rules. I'll appreciate any help offered. Blue
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