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PORTSENTRY

PORTSENTRY

Section: Maintenance Commands (8)
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NAME

portsentry - detect portscan activity  

SYNOPSIS

portsentry [ -tcp | -stcp | -atcp ]
portsentry [ -udp | -sudp | -audp ]  

DESCRIPTION

This manual page documents briefly the portsentry command. This manual page was written for the Debian GNU/Linux distribution because the original program does not have a manual page.

portsentry is a program that tries to detect portscans on network interfaces with the ability to detect stealth scans. On alarm portsentry can block the scanning machine via hosts.deny (see hosts_access(5), firewall rule (see ipfwadm(8), ipchains(8) and iptables(8)) or dropped route (see route(8)).  

OPTIONS

For details on the various modes see /usr/share/doc/portsentry/README.install
-tcp
tcp portscan detection on ports specified under TCP_PORTS in the config file /etc/portsentry/portsentry.conf.
-stcp
As above but additionally detect stealth scans.
-atcp
Advanced tcp or inverse mode. Portsentry binds to all unused ports below ADVANCED_PORTS_TCP given in the config file /etc/portsentry/portsentry.conf.

-udp
udp portscan detection on ports specified under UDP_PORTS in the config file /etc/portsentry/portsentry.conf.
-sudp
As above but additionally detect "stealth" scans.
-audp
Advanced udp or inverse mode. Portsentry binds to all unused ports below ADVANCED_PORTS_UDP given in the config file /etc/portsentry/portsentry.conf.

 

CONFIGURATION FILES

portsentry keeps all its configuration files in /etc/portsentry. portsentry.conf is portsentry's main configuration file. See portsentry.conf(5) for details.

The file portsentry.ignore contains a list of all hosts that are ignored, if they connect to a tripwired port. It should contain at least the localhost(127.0.0.1), 0.0.0.0 and the IP addresses of all local interfaces. You can ignore whole subnets by using a notation <IP Address>/<Netmask Bits>. It is *not* recommend putting in every machine IP on your network. It may be important for you to see who is connecting to you, even if it is a "friendly" machine. This can help you detect internal host compromises faster.

If you use the /etc/init.d/portsentry script to start the daemon, portsentry.ignore is rebuild on each start of the daemon using portsentry.ignore.static and all the IP addresses found on the machine via ifconfig.

/etc/default/portsentry specifies in which protocol modes portsentry should be startet from /etc/init.d/portsentry There are currently two options:

TCP_MODE=
either tcp, stcp or atcp (see OPTIONS above).
UDP_MODE=
either udp, sudp or audp (see OPTIONS above).

The options above correspond to portsentry's commandline arguments. For example TCP_MODE=atcp has the same effect as to start portsentry using portsentry -atcp. Only one mode per protocol can be started at a time (i.e. one tcp and one udp mode).

 

FILES

/etc/portsentry/portsentry.conf main configuration file
/etc/portsentry/portsentry.ignore
IP addresses to ignore
/etc/portsentry/portsentry.ignore.static
static IP addresses to ignore
/etc/default/portsentry
startup options
/etc/init.d/portsentry
script responsible for starting and stopping the daemon
/var/lib/portsentry/portsentry.blocked.*
blocked hosts(cleared upon reload)
/var/lib/portsentry/portsentry.history
history file

 

SEE ALSO

portsentry.conf(5), hosts_access(5), hosts_options(5), route(8), ipfwadm(8), ipchains(8), iptables(8), ifconfig(8)

/usr/share/doc/portsentry/README.install

 

AUTHOR

portsentry was written by Craig H. Howland <crowland@users.sf.net>.

This manual page was stitched together by Guido Guenther <agx@debian.org>, for the Debian GNU/Linux system (but may be used by others). Some parts are just a cut and paste from the original documentation.


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
CONFIGURATION FILES
FILES
SEE ALSO
AUTHOR

This document was created by man2html, using the manual pages.
Time: 22:02:10 GMT, April 16, 2011