Sony SE366 - Manual (Page 56)

56
Configuring the Advanced Settings
Gigaset SE366 WLAN / englisch / A31008-M1063-R101-4x-7619 / configure_router.fm / 13.11.2008
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URL filter
The URL filter allows you to block access to certain Internet sites or Internet domains,
or to limit accesses to certain Internet sites. Once you have entered the relevant URLs
you can then create access rules that apply the URL filter to the selected clients in your
network.
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In the Advanced Settings – Internet – Firewall menu, select Access Control.
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Select Filtering mode, i.e. whether you wish to allow or block access to the URLs in
the list.
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Enter the required URL in the field.
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Click Delete to delete an entry. Click Add to create a new entry.
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Click OK to apply the settings.
Setting up the NAT function
Your Gigaset SE366 WLAN comes provided with the NAT (Network Address Translation)
function. With address translation, several users on your local network can access the
Internet via one or more public IP addresses. In the default setting, all local IP addresses
are mapped to your router's public IP address.
One property of NAT is that data from the Internet is not allowed into your local network
unless it has been explicitly requested by one of the PCs on that network. Most Internet
applications run behind the NAT firewall without any problems. If you request Internet
pages, for example, or send and receive e-mails, the request for data from the Internet
comes from a PC on the local network and the router allows the data through. The
router opens exactly one port for the application. A port is an internal PC address
through which the data is exchanged between a server on the Internet and a client on a
PC in the local network. Communicating via a port follows the rules of a specific protocol
(TCP or UDP).
If an external application tries to send a call to a PC within the local network, the router
will block it. There is no open port via which the data could enter the local network.
Some applications, such as games on the Internet, require several links, i.e. several ports
so that the players can communicate with each other. In addition, these applications
must also be permitted to send requests from other users on the Internet to the user on
the local network. Initially, these applications will not work if Network Address Transla-
tion (NAT) is activated.