IPFWRATE(8) BSD System Manager's Manual IPFWRATE(8)NAME
ipfwrate - set / retrieve BSD IP Rate filters
SYNOPSIS
ipfwrate [-i] [-M mlen] [-p promise] [-q quant] [-Q qlen] [index [limit]]
DESCRIPTION
The ipfwrate utility defines or retrieves statistics about the rate fil-
ters installed in the kernel.
Rate filters are specified by small positive integers. A classification
filter is installed for the rate filtering point (see ipfw(8)). This
filter should return either 0, implying the packet should not be fil-
tered, or the index value of the filter. If no filter is defined for the
index returned then the packet is not filtered.
When limit is not specified then the -M, -p, -Q, and -q flags are ig-
nored. If index is specified then statistics about that filter are dis-
played. If index is not specified then statistics about all installed
filters are displayed.
If limit is specified then a new filter is defined or an existing filter
is modified. The limit specifies the maximum number of bits per second
that are allowed through the filter. Besides specifying the limit, the
following parameters may also be specified:
-i When replacing a new filter, reset all statistics associated with
a filter and dump any packets in the delay queue.
-M mlen
When the filters promised rate (see below) is reached but not
limit, only allow packets to be passed to the output interface if
it has fewer than mlen packets in its output queue. This value
defaults to 4.
-p promise
Specify the rate in bits per second that we promise this filter.
The system makes no attempt to enforce that the sum of all the
promised rates is less than or equal to the theoretical maximum.
If too much bandwidth is promised then the promise will not be
kept.
-q quant
As long as we have fewer than quant bits of outstanding data, al-
low the next packet to be sent. This defaults to 10 times the
minimum value. The minimum value is 1 system clock cycle worth
of data ( limit / clock-rate).
-Q qlen
Queue up to qlen packets before dropping packets. This defaults
to 16.
BUGS
When the filtering parameters are changed, any packets on the deferred
queue are dropped.
SEE ALSOipfw(8), ipfwasm(8), ipfwcisco(8), ipfwcmp(8), ipfwdump(8),
ipfwlog(8)
July 6, 1997 1