the day, the hour, the minute, and the seconds). This report can be read using
the twprint utility, like this:
Click here to view code image
matthew@seymour~:$ sudo twprint--print-report -r \
/var/lib/tripwire/report/shuttle2-20020919-181049.twr | less
Other options, such as emailing the report, are supported by Tripwire, which
should be run as a scheduled task by your system’s scheduling table,
/etc/crontab, on off-hours. (It can be resource intensive on less powerful
computers.) The Tripwire software package also includes a twadmin utility
that you can use to fine-tune or change settings or policies or to perform other
administrative duties.
Plan to spend some time reading documentation if you want to use Tripwire.
It is powerful but not simple. We recommend starting with the man pages and
http://www.tripwire.com.
Securing Devices
Do not ever advertise that you have set a NIC to promiscuous mode.
Promiscuous mode (which can be set on an interface by using ifconfig’s
promisc option) is good for monitoring traffic across the network and can
often enable you to monitor the actions of someone who might have broken
into your network. The tcpdump command also sets a designated interface
to promiscuous mode while the program runs; unfortunately, the ifconfig
command does not report this fact while tcpdump is running!
Remember to use the right tool for the right job. Although you can use a
network bridge to connect your network to the Internet, it would not be a
good option. Bridges have almost become obsolete because they forward any
packet that comes their way, which is not good when a bridge is connected to
the Internet. A router enables you to filter which packets are relayed.
Viruses
In the right hands, Linux is every bit as vulnerable to viruses as Windows.
This might come as a surprise to you, particularly if you made the switch to
Linux on the basis of its security record. However, the difference between
Windows and Linux is that Linux is much easier to secure against viruses.
Indeed, as long as you are smart and diligent, you need never worry about
them. Here is why: