Date: Fri, 2 May 2003 08:28:55 -0400 From: "Ben Pfountz" <netprince@vt.edu> To: "Luigi Rizzo" <rizzo@icir.org> Cc: freebsd-ipfw@freebsd.org Subject: Re: ipfw2 on 4.8-stable accepts broadcast dhcp requests? Message-ID: <000801c310a6$65dcca90$6511a8c0@benspiece> References: <001a01c3105f$3073d160$6511a8c0@benspiece> <20030501232850.A15489@xorpc.icir.org>
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Yes, I think thats it, thank you for the clarification. Ben ----- Original Message ----- From: "Luigi Rizzo" <rizzo@icir.org> To: "Ben Pfountz" <netprince@vt.edu> Cc: <freebsd-ipfw@freebsd.org> Sent: Friday, May 02, 2003 2:28 AM Subject: Re: ipfw2 on 4.8-stable accepts broadcast dhcp requests? > could it be that dhcp uses bpf to send the packet ? In that > case, it will bypass the firewall, even if you have ether.ipfw set > > cheers > luigi > > On Thu, May 01, 2003 at 11:59:11PM -0400, Ben Pfountz wrote: > > I am running 4.8-stable updated a few days ago. I am using a firewall that > > filters clients based on their MAC address, and I noticed a new client could > > acquire a DHCP lease from the server. After staring at my ruleset for a few > > hours, I decided to try removing all rules, except for the default to deny > > rule. I tried to renew a DHCP lease from the client and immediately dhcpd > > complained about not having permission to send a response back to the > > client. > > > > I assume the dhcp request that was sent to the server (a broadcast packet) > > passed through the firewall, and the response from dhcpd (a directed packet) > > was blocked by the firewall as it tried to leave the system. > > > > I am using IPFW2, with: > > net.link.ether.ipfw: 1 > > net.inet.ip.fw.enable: 1 > > net.inet.ip.fw.one_pass: 0 > > net.inet.ip.fw.debug: 1 > > net.inet.ip.fw.verbose: 1 > > > > Is this the correct behavior for IPFW2? > > > > ----- > > Ben Pfountz > > Computer Science Undergraduate, Virginia Tech > > Computer Systems Engineer, Center for Power Electronic Systems > > > > > > _______________________________________________ > > freebsd-ipfw@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw > > To unsubscribe, send any mail to "freebsd-ipfw-unsubscribe@freebsd.org" > >
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