Firewall packet logging is a special feature that writes a line of information about each datagram that matches a particular firewall rule out to a special device so you can see them.
61
FTP active mode is somewhat nonintuitively enabled using the PORT command. FTP passive mode is enabled using the PASV command.
62
The ProFTPd daemon is a good example of an FTP server that doesn't, at least in older versions.
63
Paul can be reached at [email protected].
64
Take a look at /etc/protocols for protocol names and numbers.
65
This isn't a good thing to do if your Linux machine serves as a router. If you disable IP forwarding, it will cease to route! Do this only on a machine with a single physical network interface.
66
RealAudio is a trademark of the Progressive Networks Corporation.
67
You can contact Ambrose at [email protected].
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… and perhaps even a whole book!
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Written by Wietse Venema, [email protected].
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Usually only local hostnames obtained from lookups in /etc/hosts contain no dots.
71
While its name suggests it is an extreme measure, the PARANOID keyword is a good default, as it protects you against mailicious hosts pretending to be someone they are not. Not all tcpd are supplied with PARANOID compiled in; if yours is not, you need to recompile tcpd to use it.
72
OpenSSH was developed by the OpenBSD project and is a fine example of the benefit of free software.
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Swen can be reached at [email protected]. The NIS clients are available as yp-linux.tar.gz from metalab.unc.edu in system/Network.
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Peter may be reached at [email protected]. The current version of NYS is 1.2.8.
75
Thorsten may be reached at [email protected].
