FreeBSD Manual Pages
DUMMYNET(4) BSD Kernel Interfaces Manual DUMMYNET(4) NAME dummynet -- traffic shaper, bandwidth manager and delay emulator DESCRIPTION The dummynet system facility permits the control of traffic going through the various network interfaces, by applying bandwidth and queue size lim- itations, implementing different scheduling and queue management poli- cies, and emulating delays and losses. The user interface for dummynet is implemented by the ipfw(8) utility, so please refer to the ipfw(8) manpage for a complete description of the dummynet capabilities and how to use it. Kernel Options The following options in the kernel configuration file are related to dummynet operation: IPFIREWALL enable ipfirewall (required for dummynet) IPFIREWALL_VERBOSE enable firewall output IPFIREWALL_VERBOSE_LIMIT limit firewall output DUMMYNET enable dummynet operation HZ set the timer granularity Generally, the following options are required: options IPFIREWALL options DUMMYNET options HZ=1000 # strongly recommended Additionally, one may want to increase the number of mbuf clusters (used to store network packets) according to the sum of the bandwidth-delay products and queue sizes of all configured pipes. SEE ALSO setsockopt(2), if_bridge(4), ip(4), ipfw(8), sysctl(8) HISTORY The dummynet facility was initially implemented as a testing tool for TCP congestion control by Luigi Rizzo <luigi@iet.unipi.it>, as described on ACM Computer Communication Review, Jan.97 issue. Later it has been modi- fied to work at the IP and bridging levels, integrated with the ipfw(4) packet filter, and extended to support multiple queueing and scheduling policies. BSD October 28, 2002 BSD
NAME | DESCRIPTION | SEE ALSO | HISTORY
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=dummynet&sektion=4&manpath=FreeBSD+10.4-RELEASE>