Date: Fri, 17 Sep 2004 00:26:24 -0500 From: "Micheal Patterson" <micheal@tsgincorporated.com> To: "Norm Vilmer" <norm@etherealconsulting.com>, <freebsd-questions@freebsd.org> Subject: Re: Too many dynamic rules, sorry Message-ID: <020b01c49c76$e3d1ada0$0201a8c0@dredster> References: <414A6E9C.4060708@etherealconsulting.com>
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. ----- Original Message ----- From: "Norm Vilmer" <norm@etherealconsulting.com> To: <freebsd-questions@freebsd.org> Sent: Thursday, September 16, 2004 11:57 PM Subject: Too many dynamic rules, sorry > If I repeatedly nmap my FreeBSD 4.10 machine configured with > ipfirewall, > I get the message "Too many dynamic rules, sorry". Doing a sysctl -a > |grep ip.fw I can see the the net.inet.ip.fw.dyn_count has reached the > max value of 8192 that I set. The net.inet.ip.fw.dyn_ack_lifetime is > set > to 300, so the dynamic rule count starts going down after about 5 > minutes after the simulated attack. > > Questions: > > When this happens, if my firewall still fully operational, in other > words can I safely ignore this message? > > Is there a way to fix this? > The error "Too many dynamic rules, sorry" will cause the system to drop any packets that are covered by a keep-state entry. So, the firewall, while operational, is in a dead lock down state for any outbound traffic until the dynamic rules clear out. I'm hoping that you're checking the system with nmap from behind it, because if your outside the firewall, then you're keeping state in inbound traffic and that's bad. You only want keep-state from traffic leaving that system, not to it. -- Micheal Patterson TSG Network Administration 405-917-0600 Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message
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