FreeBSD manual
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IPFWPCAP(8) FreeBSD System Manager's Manual IPFWPCAP(8)
NAME
ipfwpcap - copy diverted packets to a file in tcpdump format
SYNOPSIS
ipfwpcap [-dr] [-b maxbytes] [-p maxpkts] [-P pidfile] portnum dumpfile
DESCRIPTION
The ipfwpcap utility is used to copy diverted packets to a file in
tcpdump(1) format. The interesting packets are diverted by ipfw(8) to a
port on which ipfwpcap listens. The packets are then dropped unless -r
is used.
The options are as follows:
-d Turns on extra debugging messages.
-r Writes packets back to the divert(4) socket.
-rr Indicates that it is okay to quit if maxbytes or maxpkts are
reached. Diverted packets will silently disappear if nothing is
listening on the divert(4) socket.
-b maxbytes
Stop dumping after maxbytes bytes.
-p maxpkts
Stop dumping after maxpkt packets.
-P pidfile
File to store PID number in. Default is
/var/run/ipwfpcap.portnr.pid.
The portnum argument specifies which divert(4) socket port to listen on.
The dumpfile argument is the path to the file to write captured packets
to. Specify `-' to write to stdout.
EXIT STATUS
The ipfwpcap utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
ipfwpcap -r 8091 divt.log &
Starts ipfwpcap as a background job listening to port 8091 and reflecting
the packets back to the socket.
ipfw add 2864 divert 8091 ip from 192.0.2.101
Example ipfw(8) rule to divert all packets from 192.0.2.101 to port 8091.
See ipfw(8) for details.
SEE ALSO
tcpdump(1), pcap(3), divert(4), ipfw(8)
HISTORY
The ipfwpcap utility first appeared in FreeBSD 7.0.
AUTHORS