|--flow-file=FLOW_FILE||FLOW_FILE refers to a file, named pipe, or the string stdin. The flow file determines which packet records should be output to the new packet file. This switch is required.|
|--msec-compare||Compare times down to the millisecond (rather than the default of second).|
|--ports-compare||For TCP and UDP data, compare the source and destination ports when matching.|
|--help||Print the available options and exit.|
|--version||Print the version number and information about how SiLK was configured, then exit the application.|
In the following examples, the dollar sign ($) represents the shell prompt. The text after the dollar sign represents the command line.
Given the pcap capture file data.pcap, convert it to a SiLK flow file:
$ rwptoflow data.pcap --packet-pass=good.pcap --flow-out=data.rw
Filter the SiLK flows---passing those records whose source IPs are found in the IPset file sip.set:
$ rwfilter --sipset=sip.set --pass=filtered.rw data.rw
Match the original pcap file against the filtered SiLK file, in effect generating a pcap file which has been filtered by sip.set:
$ rwpmatch --flow-file=filtered.rw good.pcap > filtered.pcap
For best results, the tcpdump input to rwpmatch should be the output from --packet-pass-output switch on rwptoflow. This ensures that only well-behaved packets are given to rwpmatch.
The flow file input to rwpmatch should contain single-packet flows originally derived from a tcpdump file using rwptoflow. If a flow record is found which does not represent a corresponding tcpdump record, rwpmatch will return an error.
Both the tcpdump and the SiLK file inputs must be time-ordered.
rwpmatch is an expensive I/O application since it reads the entire tcpdump capture file and the entire SiLK Flow file. It may be worthwhile to optimize an analysis process to avoid using rwpmatch until payload filtering is necessary. Saving the output from rwpmatch as a partial-results file, and matching against that in the future (rather than the original tcpdump file) can also provide significant performance gains.
SiLK supports millisecond timestamps. When reading packets whose timestamps have finer precision, the times are truncated at the millisecond position.
rwptoflow(1), rwfilter(1), silk(7), tcpdump(1), pcap(3)
|SiLK 184.108.40.206||RWPMATCH (1)||2016-04-05|