When Windows Firewall is turned on and
running, you don’t really have to do anything special to use it. It
will be on constant vigil, automatically protecting your computer from
hackers and worms trying to sneak in through unprotected ports. Ports
for common Internet tasks such as e-mail and the web will be open and
monitored so that you can easily use those programs safely.
Internet programs that don’t use standard e-mail and web ports may require that you create an exception
to the default firewall rules for incoming traffic. Examples include
instant messaging programs and some online games. When you try to use
such a program, Windows Firewall displays a security alert like the one
in Figure 1.
The message doesn’t mean that the program is
“bad.” It just means that to use the program, the Firewall has to open
a port. If you don’t recognize the program name and publisher shown,
click Cancel. If you want to use the program, first decide for which
networks the exception will be allowed. For example, if the traffic is
coming from another computer on your local network, select the Private
Networks option. For traffic coming from the Internet, select Public
Networks (you can select either or both, as needed). Then, click Allow
Access. Allowing access for a program doesn’t leave the associated port
wide open. It just creates a new rule that allows that one program to
use the port. You’re still protected because the port is closed when
you’re not using that specific program. The port is also closed to
programs other than the one for which you unblocked the port. Should
you change your mind in the future, you can always reblock the port, as
described in the next section.
Manually configuring firewall exceptions (allowed apps and programs)
Normally, when you try to use a program
(or an app) that needs to work through the firewall, you get a message
like the example shown in Figure 1.
Occasionally, you might need, or want, to manually allow or block a
program through the firewall. If you have administrative privileges,
you can do that via the Allowed Apps page shown in Figure 2.
To open that page, click Allow An App Or Program Through Windows
Firewall in System And Security (by the Windows Firewall item in
Control Panel).
Items on the list with a checkmark beside them
represent apps and features that work through the firewall. You’ll also
see any exceptions you created in response to a security alert. For
example, Trillian isn’t a Windows 8 feature, so you might not see that
one. It shows in Figure 2 because we chose to allow access for it in response to the security alert shown back in Figure 1.
You probably aren’t familiar with most of the
apps and programs listed in the Allowed Apps And Features list, so you
should not select or deselect a box just by guessing. But you don’t
need to guess, either. If you just leave things as they are, everything
will be fine. If you later decide to use one of the listed features,
you’ll be prompted at that point to allow access for the app or program
if it’s necessary to do so.
Adding an app exception
You can unblock ports for apps and
programs that aren’t listed under Allowed Apps And Features. You would
do this only if specifically instructed to do so by an app or program
manufacturer you know and trust.
If the app or program for which you want to
create an exception isn’t listed under Allowed Apps And Features, you
can do the following:
1. Click
Change Settings and then click the Allow Another App button. When you
do so, you see a list of installed programs that might require Internet
access, as shown in Figure 3.
2. Click the
app or program that you want to add to the list. Optionally, if the
program isn’t listed, but you know where it’s installed, you can use
the Browse button to get to the main executable for that program
(typically the .exe file).
3. Clicking
the Network Location Types button lets you define the addresses from
which any unsolicited traffic is expected to originate. For example, if
you’re using a program that provides communications among programs
within your local network only, you wouldn’t want to accept unsolicited
traffic coming to that port from the Internet. You’d want to accept
unsolicited traffic coming only from computers within your own network.
When you click Network Location Types, you see the options shown in Figure 4. Your options are as follows:
- Private: For home or workplace
networks. If the program in question has nothing to do with the
Internet, and is for your home or business network only, choose this
option to block Internet access, but allow programs within your own
network to communicate with each other through the program.
- Public: For public networks, such
as those in an airport or coffee shop. If you want the program to be
able to connect to the Internet, choose this option.
4. Click OK to save your settings.
Tip
You can choose the scope for the program
within the Allowed Programs And Features list just by placing a
checkmark in the Home/Work (Private) or Public columns for the program.
IP Addresses on Home/Office Networks
When you set up a network using the
Network Setup Wizard , each computer
is automatically assigned a 192.168.0.x IP address, where x
is unique to each computer. For example, if the computers are sharing a
single Internet connection, the first computer may receive the
192.168.0.1 address, and the subsequent computers will also have
addresses in that same address space.
All computers will have the same
subnet mask of 255.255.255.0. The subnet mask just tells the computer
that the first three numbers are part of the network address (the address of your network as a whole), and the last number refers to a specific host (computer) on that network. The 192.168 . . . addresses are often referred to as private addresses because they cannot be accessed directly from the Internet.
To see the IP address of a computer on your local network:
1. Go to that computer, display the desktop, press Windows+X, and choose Command Prompt.
2. At the
command prompt, type ipconfig /all and press Enter. You see the
computer’s IP address and subnet mask listed along with other Internet
Protocol data.
Disabling, changing, and deleting exceptions
The check boxes in the Allowed Apps And
Features list indicate whether the exception is enabled or disabled.
When you clear a check box, the exception is disabled and traffic for
that program is rejected. This makes it relatively easy to enable and
disable a rule for a program on an as-needed basis because the program
name always remains in the list of exceptions.
To change the scope of an exception in your
exceptions list, click the check box in the Private or Public column,
as needed. To remove a program from the exceptions list, and stop
accepting unsolicited traffic through its port, click the program name
and then click the Remove button.
Tip
You cannot remove the default programs from the list — only those you have added.