Book Excerpt: Practical Guide to Ubuntu Linux, A, 3rd Edition

“Securing a Server

“Two ways you can secure a server are by using TCP wrappers and
by setting up a chroot jail. This section describes both
techniques. TCP Wrappers: Secure a Server (hosts.allow and
hosts.deny)

“Follow these guidelines when you open a local system to access
from remote systems:

* Open the local system only to systems you want to allow to
access it.

* Allow each remote system to access only the data you want it
to access.

* Allow each remote system to access data only in the
appropriate manner (readonly, read/write, write only).”

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