Wer keine Netzwerk-Tap zur Hand hat muss sich halt so helfen:

ssh switch.example.com
conf t
monitor session 1 source interface Gi0/XX
monitor session 1 destination interface Gi0/YY
end
show monitor session 1


Ein Nagios-Plugin von Heise, welches Mail-Server IP-Adressen gegen diverse DNS-Blacklisten prüft.

define command {
command_name check_dnsblk
command_line /usr/local/nagios/libexec/dnsbl-check-nagios.sh -H $HOSTADDRESS$
}

define service {
use generic-service
host_name mx.example.com
service_description dnsblk
display_name Mail DNS-Blacklist
check_command check_dnsblk
contact_groups Administratoren
}


Howto um mod_security unter Ubuntu Server 8.04 zu installieren:

wget http://etc.inittab.org/~agi/debian/libapache-mod-security2/mod-security-common_2.5.9-1_all.deb
wget http://etc.inittab.org/~agi/debian/libapache-mod-security2/libapache-mod-security_2.5.9-1_i386.deb
dpkg -i libapache-mod-security_2.5.9-1_i386.deb mod-security-common_2.5.9-1_all.deb
nano -w /etc/apache2/conf.d/modsecurity2.conf

<ifmodule mod_security2.c>
Include /etc//modsecurity/*.conf
</ifmodule>

mkdir /etc/modsecurity/
mkdir /var/log/apache2/mod_security/
cd /etc/modsecurity/

wget http://www.modsecurity.org/download/modsecurity-core-rules_2.5-1.6.1.tar.gz
tar xvfz modsecurity-core-rules_2.5-1.6.1.tar.gz
nano -w modsecurity_crs_10_config.conf

...
SecAuditLog /var/log/apache2/mod_security/modsec_audit.log
SecDebugLog /var/log/apache2/mod_security/modsec_debug.log
...
a2enmod mod-security
/etc/init.d/apache2 force-reload