Hi all, I am trying to solve a tiny problem that is trivial to solve using dummynet (FreeBSD). I just want to add a delay of 50ms to each outgoing packet from an interface. This is to simulate a large pool of multiple modem users so I also need to add b/w limits etc (which seems to be easy to do). From the mailing list I could fine 2 qdiscs that can simulate latency : "delay" & "netem". Neither of them is working on my setup though ( Fedora core2 [2.6.5] or RHEL 3.0 update 2 or gentoo [2.6.8] ). Is something special needed to enable these qdiscs ? I tried applying the patch (http://www.uwsg.iu.edu/hypermail/linux/net/0403.2/0019.h tml) and recompiled the kernel but the tc command returns "RTNETLINK answers: Invalid argument". What am I doing wrong ? Thanks much, -ansh _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
On Fri, 2004-10-08 at 15:38 -0700, Anshuman Kanwar wrote:> Hi all, > > I am trying to solve a tiny problem that is trivial to > solve using dummynet (FreeBSD). > > I just want to add a delay of 50ms to each outgoing > packet from an interface. This is to simulate a large > pool of multiple modem users so I also need to add b/w > limits etc (which seems to be easy to do). > > >From the mailing list I could fine 2 qdiscs that can > simulate latency : "delay" & "netem". Neither of them is > working on my setup though ( Fedora core2 [2.6.5] or RHEL > 3.0 update 2 or gentoo [2.6.8] ). Is something special > needed to enable these qdiscs ?delay was my earlier name, netem is the current one. Netem went in to mainline kernel 2.6.8 (also 2.4.27)> I tried applying the patch > (http://www.uwsg.iu.edu/hypermail/linux/net/0403.2/0019.h > tml) and recompiled the kernel but the tc command returns > "RTNETLINK answers: Invalid argument".You probably need to build/run newer version of tc see http://developer.osdl.org/dev/iproute2 _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Hi Stephen, Getting the latest iproute2 solved my problem. Thanks! -----Original Message----- From: Stephen Hemminger [mailto:shemminger@osdl.org] Sent: Friday, October 08, 2004 3:55 PM To: Anshuman Kanwar Cc: lartc@mailman.ds9a.nl Subject: Re: [LARTC] Delay packets by 50ms On Fri, 2004-10-08 at 15:38 -0700, Anshuman Kanwar wrote:> Hi all, > > I am trying to solve a tiny problem that is trivial tosolve using> dummynet (FreeBSD). > > I just want to add a delay of 50ms to each outgoingpacket from an> interface. This is to simulate a large pool of multiplemodem users so> I also need to add b/w limits etc (which seems to beeasy to do).> > >From the mailing list I could fine 2 qdiscs that can > simulate latency : "delay" & "netem". Neither of themis working on my> setup though ( Fedora core2 [2.6.5] or RHEL 3.0 update2 or gentoo> [2.6.8] ). Is something special needed to enable theseqdiscs ? delay was my earlier name, netem is the current one. Netem went in to mainline kernel 2.6.8 (also 2.4.27)> I tried applying the patch >(http://www.uwsg.iu.edu/hypermail/linux/net/0403.2/0019.h> tml) and recompiled the kernel but the tc commandreturns "RTNETLINK> answers: Invalid argument".You probably need to build/run newer version of tc see http://developer.osdl.org/dev/iproute2 _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/