Obviously, this new rule must be edited. Since this object is a host, that object will be placed into either the Source or Destination section of the newly created firewall rule. Since the newly created Host object lives within the internal network and assumes that host can be trusted it will be added to the new rule as a Source and will be allowed to pass through the firewall.
Find the newly created Host Object in the Object Tree and drag and drop it to the Source section of the newly created rule see Figure 5. It is clear, in the current state, the host just added is not allowed into the destination. In order to change that Deny a red dot to Allow a green dot right click the Deny entry for the new rule and select Accept. The red dot will change to a green dot, indicating the host is allowed through.
If there are multiple hosts to add, create new rules for each host and repeat the same process. Hosts are not the only object that can be added.
Services are added to the Object tree in the same way hosts are added. Services are also added into the firewall in the same way Hosts are added. Once the firewall has been created, it is necessary to compile and install the firewall. These two processes will make sure the firewall is correctly built, compiled such that the firewall is in a form the system can use, and installed so the firewall is being used by the system. These processes are simple. Upon completion of the firewall do the following:.
As soon as the installation is complete, the firewall will be running. This installation will also ensure the firewall runs upon reboot of the machine. If changes are made in the currently running firewall, it is necessary to re-compile and re-install the firewall. Firewall Builder is an incredibly powerful and flexible security tool that any Linux administrator should get to know.
And with Firewall Builder, both very simple yet powerful firewalls can be created as can incredibly complex and powerful firewalls. About Us. Sign in. Forgot your password? Get help. Password recovery. Training and Tutorials. Save and close sources. Install the fwbuilder libraries with the command sudo apt-get install libfwbuilder. Install fwbuilder with the command sudo apt-get install fwbuilder. The Graphical Interface In order to start up fwbuilder administrative privileges will be necessary.
Creating a New Firewall When the Create New Firewall button is clicked, a wizard will appear to help create the new firewall. Because I recommend first-time users select from the pre-configured templates, the wizard will require the following: A name for the firewall.
Software the firewall is based on such as iptables. Firewall Builder fwbuilder is a graphical application that can help you to configure IP traffic filtering. It can compile the filtering policy you define into many specifications, including iptables and various languages used by Cisco and Linksys routers. Separating the actual policy you define and the implementation in this way should let you change what hardware is running your firewall without having to redefine your policy for that platform.
Packages for fwbuilder are available in the Ubuntu Hardy and Fedora 9 repositories. You have to install the library first.
Install the two packages using the normal. I found the below warning during configuration; if you get it, you can ignore it. By right-clicking on the Firewalls item in the tree view you can create a new firewall. If you choose to enable firewall templates and create an iptables firewall, you will see the dialog window shown. Because fwbuilder has a selection of firewalls that are identical or close to what many users will want to use, it makes getting started much simpler.
Template 1, shown in the screenshot, supports a dynamic IP address assigned by your ISP and a local fixed private subnet on a second network interface of the server. Template 2 is similar to template 1 but is designed for the server to be a DHCP server for your local network. Template 3 is designed for setting up a demilitarized zone DMZ subnet by having three network interfaces on the server — one facing the Internet with a static IP address, a local private subnet, and a DMZ subnet that is accessible from the Internet.
The fourth item on the list, host fw template 1, simply protects a single host, only allowing incoming SSH access. While the policy for this sort of firewall is simple, having it in the list allows laptop users to install a firewall quickly. The linksys firewall template is designed specifically to run on Linksys routers, while the c36xx is an example for Cisco routers. The firewall rules for Template 1 are shown in the screenshot below.
As you click on each cell in the grid in the top of the window, the bottom pane changes to allow you to edit the data in that cell. Instead of simply entering a TCP connection type and a port number, the template firewall offers the SSH service as an option in the tree view on the left side, which is what this rule is using to define where the connection is destined. The service that the template refers to is part of the system definitions and is read-only, allowing you to see the details in the pane but not edit them.
Note that template firewall object comes completely configured, including addresses and netmasks of its interfaces and some basic policy and NAT rules. This configuration is intended as a starting point only. You should reconfigure addresses of interfaces to match those used on your network and most likely will have to adjust rules to match your security policy.
This page of the wizard shows template objects and their configuration. Standard template objects represent firewalls with two or three interfaces, a host with one interface, web server or Cisco router. Choose firewall with three interfaces for this guide. Note that template comes with completely configured firewall object, including set of interfaces and their ip addresses and some basic firewall policy.
You will see how addresses can be changed later on in this guide. Click "Finish" to create a new firewall object using chosen template. Here is our new firewall object. Its name is guardian , it appears in the object tree in the left hand side of the main window in the folder Firewalls. When an object is selected in the tree, a brief summary of its properties appears in the panel under the tree. Double-clicking on the object in the tree opens it in the editor panel at the bottom of the right hand side panel of the main window.
The editor for the firewall object allows the user to change its name, platform and host OS and also provides buttons that open dialogs for "advanced" settings for the firewall platform and host OS. We will inspect these little later in this tutorial. Now would be a good time to save the data to a disk file.
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