User`s guide

MBR W40 – Admin’s Manual
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3. Select Block IP Fragments to protect the local network from a common type of hacker attack that could make
use of fragmented data packets to sabotage your home network. Note that VPN over IPSec and some UDP-
based services make legitimate use of IP fragments. You should be careful not to block IP fragments from the
local network if you want to make use of these select services.
4. Click OK to save the settings.
Note: Using the Minimum Security setting may expose the home network to significant security risks, and therefore
should only be used when necessary and only for short periods of time.
3.7.3.2 Access Control
You may want to block specific computers within the local network (or even the whole network) from accessing
certain services on the Internet. For example, you may want to prohibit one computer from surfing the Web, another
computer from transferring files using FTP, and the whole network from receiving incoming e-mail. Access Control
defines restrictions on the types of requests that may pass from the local network out to the Internet, and thus may
block traffic flowing in both directions. It can also be used to allow specific services when maximum security is
configured. In the e-mail example given above, you may prevent computers in the local network from receiving e-mail
by blocking their outgoing requests to POP3 servers on the Internet. There are numerous services you may want to
consider blocking, such as popular games and file sharing servers.
Note: When Web Filtering is enabled, HTTP services cannot be blocked by Access Control.
 To allow or restrict services:
1. In the Firewall menu, click the Access Control link. The Access Control screen appears.
Figure 61: Firewall - Access Control
2. Click the New Entry link. The Add Access Control Rule screen appears.
Figure 62: Add Access Control Rule
3. Under Address, select the computer or group of computers on which you would like to apply the access-
control rule. Select an address or a name from the list, or any to apply the rule on all the hosts that are
connected to W40 local network.