A firewall is a vital component in protecting a computer system, or network of computers from external attack (typically from an internet connection). Any computer connected directly to an internet connection must run a firewall to protect against malicious activity. Similarly, any internal network must have some form of firewall between it and an external internet connection.
A firewall is a vital component in protecting a computer system, or network of computers from external attack (typically from an internet connection). Any computer connected directly to an internet connection must run a firewall to protect against malicious activity. Similarly, any internal network must have some form of firewall between it and an external internet connection.
Fedora Linux is supplied with powerful firewall technology known as ''iptables'' built-in. Entire books can, and indeed have, been written about configuring iptables. If you would like to learn about ''iptables'' we recommend [http://www.linuxtopia.org/Linux_Firewall_iptables/index.html Linux Firewall Configuration - Packet Filtering and iptables].
Fedora Linux is supplied with powerful firewall technology known as ''iptables'' built-in. Entire books can, and indeed have, been written about configuring iptables. If you would like to learn about ''iptables'' we recommend [http://www.linuxtopia.org/Linux_Firewall_iptables/index.html Linux Firewall Configuration - Packet Filtering and iptables].
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Fortunately Fedora Linux also provides some tools which make firewall configuration easy for the average user. This chapter will cover the steps necessary to configure a Fedora Linux firewall using those tools.
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Fortunately Fedora Linux also provides some tools that make firewall configuration easy for the average user. This chapter will cover the steps necessary to configure a Fedora Linux firewall using those tools.
== Fedora Linux Firewall Options ==
== Fedora Linux Firewall Options ==
Enter your password when prompted. Once loaded, the security level tool should appear as follows:
Enter your password when prompted. Once loaded, the security level tool should appear as follows:
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== Configuring Other Ports ==
== Configuring Other Ports ==
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The list of well known ports are not, of course, the only ports available. In fact there are thousands of ports available for use by applications and services. To open a specific port use the ''Other ports'' category of the Firewall Configuration tool. To open a port, click on the ''Add'' button to display the ''Port and Protocol'' dialog shown below:
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The list of well known ports are not, of course, the only ports available. In fact there are thousands of ports available for use by applications and services. To open a specific port, use the ''Other ports'' category of the Firewall Configuration tool. To open a port, click on the ''Add'' button to display the ''Port and Protocol'' dialog shown below:
Masquerading is better known in networking circles as Network Address Translation (NAT). When using a Fedora system as a gateway to the internet for a network of computers, masquerading allows all of the internal systems to use the IP address of the Fedora system when communicating over the internet. This has the advantage of hiding the internal IP addresses of any systems from malicious external entities and also avoids the necessity to allocate a public IP address to every computer on the network.
Masquerading is better known in networking circles as Network Address Translation (NAT). When using a Fedora system as a gateway to the internet for a network of computers, masquerading allows all of the internal systems to use the IP address of the Fedora system when communicating over the internet. This has the advantage of hiding the internal IP addresses of any systems from malicious external entities and also avoids the necessity to allocate a public IP address to every computer on the network.
