Before you start
Objectives: Learn how to create new rules in Windows Firewall with Advanced Security. We will create outbound rule in this example, but the principle is the same for the inbound rules.
Prerequisites: you have to know what is firewall in general.
Key terms: rule, IP, address, firewall, port, remote, screen WFAS, example, access, option, outbound
Windows Firewall With Advanced Security (WFAS)
As you should know, with WFAS we have more granular control when compared to ordinary Windows Firewall which is also available in Windows 7. To open WFAS, simply start entering “windows firewall” in search and select “Windows Firewall with Advanced Security” option.
Once we open WFAS we will see a list of rules. Rules are divided to the Inbound, Outbound and Connection Security rules. Notice that there is a lot of predefined rules that we can use. Some of them are enabled, and some of them are disabled. Each rule can be disabled/enabled for the different network profile (domain, private, public). We can also see the application that the rule relates to, the action, the protocol that is used, local and remote address, the local and remote port, allowed users and allowed computers.
To restrict access to our computer we would edit the Inbound rules. To restrict users to access remote resources, we would go to the Outbound rules section. This is what we will do in this example. For the purpose of this demo we will block users on our local computer to access the www.saadz26.sg-host.com site. So, to add a new rule, we can right-click on the Outbound rules section, all click on the New Rule option from the menu on the right side of the window.
New Rule Option
On the first screen we can choose to create rules based on programs, ports or use a predefined rule. We can also create a custom rule, which we will do in our example.
Custom Rule Option
On the next screen we can specify if this rule applies to all programs or only to a specific program. For example, here we could choose only specific Web Browsers. We could also apply this rule to specific services only. For the purpose of this demo we will choose the “All programs” option and click Next.
On the next screen we have to choose the right protocols and ports. For this, you have to know about different networking protocols and their specific ports. For example, to access web sites our Web Browsers use HTTP protocol. HTTP protocol uses TCP transport layer protocol, on port 80 by default. When configuring the Outbound rule, it is more important to configure the Remote port. The local port is actually auto-generated when the connection gets established, and it is used as a return path. Because of that, we don’t have to enter it here. The remote port is the port we are connecting to. For the remote port we will use the specific port 80.
On the next screen we have to choose the IP addresses that this rule applies to. For the local IP address we can choose the “Any IP address” option or choose to enter specific IP address. In this case this is not important since this rule will only be applied to the local machine. However, if we were to configure this rule trough Group Policy and push it down to our machines, we would then have to specify the specific IP addresses that this rule should be applied to.
If we click on the Customize button we can also select which interfaces this rule applies to. By default it will be applied to all interfaces, but we can choose to only apply it to wired or wireless interfaces, or to remote access sessions.
The important thing to configure is the remote IP addresses to which this rule applies to. So, we have to know the IP address of the www.saadz26.sg-host.com site. To get the IP address we will try and PING it in the command line.
We got the reply and now we know that the IP address is 18.104.22.168. Let’s click on the Add button and enter the IP address.
IP Address Specified
Notice that in this window we can also enter the whole subnet, the range of IP addresses, or some predefined set of computers (WINS servers, DHCP servers, DNS servers, or local subnet computers. When we click OK, our screen now looks like this.
IP Address Entered
On the next screen we choose the action we want to be performed for this rule. In our case we will block the connection.
On the next screen we have to choose the network profile that this rule applies to. The default is all profiles.
On the next screen we enter the name of our rule and a brief description.
When we click Finish, we will see our new rule in the list.
When we try to browse to the www.saadz26.sg-host.com now, we well see something like this.
Bigger organizations often use multiple IP addresses assigned to multiple servers which all serve the same web site. For example, facebook.com uses several ranges of IP addresses, and in order to block facebook.com we have to enter all those IP addresses (or ranges) in our outbound firewall rule in order to block access to facebook, for example.