Re: packet order, ipf or ipfw

From: Dinesh Nair (dinesh_at_alphaque.com)
Date: 07/30/04

  • Next message: Charlie Schluting: "Re: packet order, ipf or ipfw" 
    Date: Fri, 30 Jul 2004 19:14:12 +0800 (MYT)
To: Jeremie Le Hen <jeremie.le-hen@epita.fr>

    On Thu, 29 Jul 2004, Jeremie Le Hen wrote:

    > Hello Charlie,
    >
    > > I'm running ipf because I like it ...but now I need to use ipfw's pipe
    > > feature. I was thinking that I could just run both, and keep all my
    > > rules in ipf, then in ipfw: limit bandwidth for a few vlans, then allow all.
    > >
    > > It didn't work (no rate-limiting happened).. and I'm thinking that ipf
    > > is passing the packets and bypassing ipfw? Or something..
    > >
    > > So, what is the order, if I'm running ipf AND ipfw at the same time?
    > > Will it work at all in this manner?
    >
    > But you should be warned that using ipnat(8) in conjunction to ipfw
    > pipes may lead to an incorrect behaviour :
    > http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/61685

    in addition, http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/46564
    reverses the order in which ipfw/ipfilter/ipnat processes packets in
    ip_output.c to make it consistent if both are used.

    by default the flow is:

    wire -> ipnat -> ipfilter -> ipfw -> kernel -> ipfilter -> ipnat ->ipfw

    the patch in the above PR changes it to:

    wire -> ipnat -> ipfilter -> ipfw -> kernel -> ipfw -> ipfilter -> ipnat

    personally, i prefer the patch to ip_output as it makes it cleaner when
    you're separating between using ipfw/dummynet for shaping and
    ipfilter/ipnat for firewalling.

    Regards, /\_/\ "All dogs go to heaven."
    dinesh@alphaque.com (0 0) http://www.alphaque.com/
    +==========================----oOO--(_)--OOo----==========================+
    | for a in past present future; do |
    | for b in clients employers associates relatives neighbours pets; do |
    | echo "The opinions here in no way reflect the opinions of my $a $b." |
    | done; done |
    +=========================================================================+

    _______________________________________________
    freebsd-net@freebsd.org mailing list
    http://lists.freebsd.org/mailman/listinfo/freebsd-net
    To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"

  • Next message: Charlie Schluting: "Re: packet order, ipf or ipfw"

    Relevant Pages