argus - audit record generation and utilization system

argus [ options ] [ filter expression ]

Copyright (c) 2000-2004 QoSient, LLC All rights reserved.

Argus is an IP transaction auditing tool that categorizes IP packets which match the boolean expression into a protocol-specific network transaction model. Argus reports on the transactions that it discovers, as they occur.

Designed to run as a daemon, argus generally reads packets directly from a network interface, and writes the transaction status information to a log file or open socket connected to an argus client (such as ra(1)). Argus can also read packet information from tcpdump(1) , snoop(1) or NLANR's Moat Time Sequence Header raw packet files. Argus can also be configured to write its transaction logs to stdout.

Argus provides access control for its socket connection facility using tcp_wrapper technology. Please refer to the tcp_wrapper distribution for a complete description.

-b

Dump the compiled packet-matching code to stdout and stop. This is used to debug filter expressions.

-B

Only bind to the specified IP address (remote access must be enabled by a non-zero port).

-c

Generate system pid file. This will cause argus to create a pid file that can be used to control the number of argi running on a system. The default pid file directory is /var/run, and $ARGUSHOME, when the OS does not suppor /var/run.

-d

Run argus as a daemon. This will cause argus to do the things that Unix daemons do and return, if there were no errors, with argus running as a detached process.

-D

<level> Print debug messages to stderr. The higher the <level> the more information printed. Acceptable levels are 1-8.

-e

<value> Specify the source identifier for this argus. Acceptable values are numbers, hostnames or ip address.

-h

Print an explanation of all the arguments.

-F

Use conffile as a source of configuration information. Options set in this file override any other specification, and so this is the last word on option values.

-I

<number> Specify the <number> of instances that are concurrently allowed. The default is 1. This is impacts the pid file strategy for argus.

-i

<interface> Specify the physical network <interface> to be audited. The default is the first network interface that is up and running.

-J

Generate packet peformance data in each audit record.

-M

<secs> Specify the interval in <secs> of argus status records. These records are used to report the internal status of argus itself. The default is 300 seconds.

-m

Don't provide MAC addresses information in argus records.

-n

<directory> Specify the pid file directory. This overrides the default directory location, which is /var/run, or $ARGUSHOME if /var/run is not available. This switch implies the -c switch.

-O

Turn off Berkeley Packet Filter optimizer. No reason to do this unless you think the optimizer generates bad code.

-p

Do not set the physical network interface in promiscuous mode. If the interface is already in promiscuous mode, this option may have no effect. Do this to audit only the traffic coming to and from the system argus is running on.

-P

<portnum> Specifies the <portnum> for remote client connection. The default is to not support remote access. Setting the value to zero (0) will forceably turn off the facility.

-r

Read from tcpdump(1) , snoop(1) or NLANR's Moat Time Sequence Header (tsh) packet capture files. If the packet capture file is a tsh format file, then the -t option must also be used. Argus will read from only one input packet file at a time. If the -r option is specified, argus will not put down a listen(2) to support remote access.

-R

Generate argus records such that response times can be derived from transaction data.

-S

<secs> Specify the status reporting interval in <secs> for all traffic flows.

-t

Indicate that the expected packet capture input file is a NLANR's Moat Time Sequence Header (tsh) packet capture file.

-U

Specify the number of user bytes to capture.

-w

<file ["filter"] Write transaction status records to output-file. An output-file of '-' directs argus to write the resulting argus-file output to stdout.

-X

Clear existing argus configuration. This removes any initialization done prior to encountering this flag. Allows you to eliminate the effects of the /etc/argus.conf file, or any argus.conf files that may have been loaded.

expression

This tcpdump(1) expression specifies which transactions will be selected. If no expression is given, all transactions are selected. Otherwise, only transactions for which expression is `true' will be dumped. For a complete expression format description, please refer to the tcpdump(1) man page.

Argus catches a number of signal(3) events. The three signals SIGHUP, SIGINT, and SIGTERM cause argus to exit, writing TIMEDOUT status records for all currently active transactions. The signal SIGUSR1 will turn on debug reporting, and subsequent SIGUSR1 signals, will increment the debug-level. The signal SIGUSR2 will cause argus to turn off all debug reporting.

$ARGUSHOME - Argus Root directory

/etc/argus.conf        - argus daemon configuration file 
/var/run/argus_os.pid  - default PID file nameing convention

Run argus as a daemon, writing all its transaction status reports to output-file. This is the typical mode.

argus -d -e `hostname` -w output-file

If ICMP traffic is not of interest to you, you can filter out ICMP packets on input.

argus -w output-file - ip and not icmp

Argus supports both input filtering and output filtering, and argus supports multiple output streams, each with their own independant filters.

If you are interested in tracking IP traffic only (input filter) and want to report ICMP traffic in one output file, and all other IP traffic in another file.

argus -w outfile1 "icmp" -w outfile2 "not icmp" - ip

Audit the network activity that is flowing between the two gateway routers, whose ethernet addresses are 00:08:03:2D:42:01 and 00:00:0C:18:29:F1. Without specifying an output-file, it is assumed that the transaction status reports will be written to a remote client. In this case we have changed the port that the remote client will use to port 430/tcp.

argus -P 430 ether host (0:8:3:2d:42:1 and 0:0:c:18:29:f1) &

Audit each individual ICMP ECHO transaction. You would do this gather Round Trip Time data within your network. Write the output to output-file.

argus -R -w output-file "echo" - icmp

Audit all NFS transactions involving the server fileserver and increase the reporting interval to 3600 seconds (to provide high data reduction). Write the output to output-file.

argus -S 3600 -w output-file udp and port 2049 &

Carter Bullard (carter@qosient.com)

argus.conf(5), hosts_access(5), hosts_options(5), tcpd(8), tcpdump(1)