TITLE:          Port Scan Detection 
LFS VERSION:    3.3
AUTHOR:	        yoonsoo <yoonsoo@gmx.net>


SYNOPSIS:
	How to detect port scans 

HINT:
Version 0.2
20/05/2002

Contents
--------

    1. Preface
    2. packages needed to be downloaded
    3. installation of the packages
    4. testing
    5. TODO

1. Preface
   -------
	The first step of an attacker may be the scanning of your box
	to find out what services you have running. Other way round it
	could be helpful for yourself to scan your own machine to find
	some security leaks. So both, a port scanner and a scan detector 
	could help to raise the security a little bit.

2. packages needed to be downloaded
   --------------------------------
	
	libpcap-0.7.1 ( www.tcpdump.org/release/ )
	Libnet-1.0.2a ( www.packetfactory.net/Projects/Libnet/ )
	libnids-1.16 ( www.packetfactory.net/Projects/Libnids/ )
	scanlogd-2.2 ( www.openwall.com/scanlogd/ )
	nmap-2.54BETA34 ( www.insecure.org/nmap/ )

3. Installation
   ------------
	 
	libpcap-0.7.1 
		./configure --prefix=/usr
		make 
		make install

/* optional (will be needed for additiona packages maybe)

	Libnet-1.0.2a
		./configure 
		make
		make install

	libnids-1.16
		./configure 
		make
		make install

*/

	scanlogd-2.2
		make linux
		mv scanlogd /usr/sbin
		mv scanlogd.8 /usr/share/man/man8
		useradd -g daemon scanlogd
		echo "daemon.alert -/var/log/alert.log" >> /etc/syslog.conf

		creating Startscript :

cat > /etc/rc.d/init.d/scanlogd << "EOF"
#!/bin/bash

source $rc_functions

case "$1" in
	start)
		echo "Starting PortScan Logging Facility..."
		loadproc scanlogd
		;;
	stop)
		echo "Stopping Portscan Logging..."
		killproc scanlogd
		;;
	*)
		echo "Usage: $0 {start|stop}"
		exit 1
		;;
esac
EOF

		nmap-2.54BETA34
        ---------------
		
			export GTK_CONFIG=/usr/X11R6/bin/gtk-config *)
			configure --prefix=/usr
			make
			make install

*) if you dont have gtk and gnome installed, you will have to
disable gtk and compile it without gtk support. In this case you will
not have nmapfe (the gtk-frontend to nmap), otherwise specify the path
to your gtk-config

4. Testing
----------

Now you can test both. Scan your box with nmap (or nmapfe) and check the
file /var/log/alert.log.

or use 

http://scan.sysgatetech.com

As it is already mentioned on the documentations of scanlogd, this does
NOT prevent any port scan but just logging them.


5.TODO
------

add some more programs and daemons to raise the security of LFS

---------------------------------------------------
For additions remarks and bugs please contact me on

yoonsoo@gmx.net. thx.
----------------------------------------------------
