Date: Fri, 3 Apr 2009 11:38:12 +0700 From: Victor Sudakov <sudakov@sibptus.tomsk.ru> To: freebsd-questions@freebsd.org Cc: Victor Sudakov <vas@mpeks.tomsk.su> Subject: Re: keep-state and divert Message-ID: <20090403043811.GA70473@admin.sibptus.tomsk.ru> In-Reply-To: <20090402055113.GA35989@admin.sibptus.tomsk.ru> References: <20090402055113.GA35989@admin.sibptus.tomsk.ru>
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Victor Sudakov wrote: > If we consider a simple example below, how would you replace the 600th > rule for a stateful one? > > 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 allow ip from table(1) to any in via rl0 > 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 > It seems that the ruleset should be reordered and changed to the following: 00100 divert 8668 ip from table(1) to any in via rl0 00200 check-state 00300 deny log logamount 100 ip from any to 10.0.0.0/8 in via rl0 00300 deny log logamount 100 ip from any to 172.16.0.0/12 in via rl0 00300 deny log logamount 100 ip from any to 192.168.0.0/16 in via rl0 00400 skipto 500 ip from any to table(1) out via rl0 keep-state 00500 divert 8668 ip from any to table(1) out via rl0 00600 deny log logamount 100 ip from 10.0.0.0/8 to any out via rl0 00600 deny log logamount 100 ip from 172.16.0.0/12 to any out via rl0 00600 deny log logamount 100 ip from 192.168.0.0/16 to any out via rl0 65535 allow ip from any to any It seems to work. However there is an obscure moment in it. When I look at the dynamic rules being created, for each connection I see two rules: one with the private source address and another with a NAT'ed source address. Which means the outgoing packet traverses the 400th rule twice. I don't understand how this happens. -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN sip:sudakov@sibptus.tomsk.ru
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