Restrict Information Published by Avahi
If it is necessary to publish some information to the network, it should not be joined
by any extraneous information, or by information supplied by a non-trusted source
on the system.
Prevent user applications from using Avahi to publish services by adding or
correcting the following line in the '[publish]' section:
Disable Printer Browsing Entirely if Possible
By default, CUPS listens on the network for printer list
broadcasts on UDP port 631. This functionality is called printer browsing.
To disable printer browsing entirely, edit the CUPS configuration
file, located at '/etc/cups/cupsd.conf', to include the following:
Disable Print Server Capabilities
To prevent remote users from potentially connecting to and using
locally configured printers, disable the CUPS print server sharing
capabilities. To do so, limit how the server will listen for print jobs by
removing the more generic port directive from /etc/cups/cupsd.conf:
and replacing it with the 'Listen' directive:
This will ...
Disable DHCP Service
The 'dhcpd' service should be disabled on
any system that does not need to act as a DHCP server.
The 'dhcpd' service can be disabled with the following command:
'$ sudo systemctl disable dhcpd'
Uninstall DHCP Server Package
If the system does not need to act as a DHCP server,
the dhcp package can be uninstalled.
The 'dhcp' package can be removed with the following command:
'$ sudo yum erase dhcp'