Cyber Security:
Configuring a Firewall
You need to have Administrator level access to the computer you use as you will be making changes to important parts of the operating system. So if you own the computer that is fine - if not you need permission from the 'Administrator'
If your computer is in an office environment, or is supplied by your employer, you need to check that you are permitted to change the firewall settings before you do so. Many employers have preferred settings that are maintained by specialist staff and you should not attempt to change them without permission.
Windows 10
If you have Windows 10, your firewall should be on by default.
Use the information on Microsoft’s support page to check the firewall is turned on:
https://support.microsoft.com/en-us/help/4028544/windows-10-turn-windows-defender-firewall-on-or-off
Apple
Apple takes responsibility for the security functions of their devices.
You can read their latest information at: https://www.apple.com/ business/ docs/ site/ iOS_Security_Guide.pdf .
Linux
If you are using Linux you have a lot of choice about which firewall to run. See these articles for more information:
https://www.tecmint.com/ open-source-security-firewalls-for-linux-systems/
https://www.techradar.com/ news/ best-free-linux-firewall
https://opensource.com/ article/ 18/ 9/ linux-iptables-firewalld
Configuring your own firewall in Windows 7
If you have Windows 7, go to the Start menu.
Choose Control Panel, and then System And Security.
One of the options is for Windows Firewall. Click it. Click Turn Windows Firewall On or Off.
You may need to enter an administrator password depending on how your Windows is set up.
If the firewall is not already active, click Turn on Windows Firewall for each of the network types that your computer supports.
The Windows Firewall gives you a range of options depending on how much data you wish to allow through the firewall.
When the firewall is first activated, the majority of applications are automatically blocked.
But you can overrule this block by checking the Notify Me check box when the Windows Firewall blocks a new app.
From then on, every time an application first attempts to connect to the network, Windows will prompt you, asking if you wish to give it permission to do so. Your choice is remembered by the firewall. You should only give permission if you are sure the application is safe.
If you want to get maximum protection from the firewall, select the Block All Incoming Connections option, including those in the list of allowed apps. This will prevent other computers connecting to your machine unless your computer has requested data.
This is a very useful option if you're travelling and using public Wi-Fi networks.
Configuring your own firewall (Mac)
On an Apple Mac, you can access the firewall using the System Preferences.
Choose Security and Privacy.
On the Security and Privacy Preferences pane, select the Firewall tab.
If the firewall is not already enabled, click the Turn On Firewall button.
You may need to click the padlock icon and provide your password to do this.
Once the firewall is enabled, you can access its settings by clicking the Firewall Options button.
Clicking the Block All Incoming Connections button will stop network traffic from external computers other than the traffic relating to some basic network services.
The list of software under this check box specifies the programmes that are allowed to send and receive data from the network.
Software can be added to this list by clicking the Plus button underneath it.
The check box to automatically allow assigned software to receive incoming connections allows those applications that have been digitally signed to send and receive data.
Finally, the Stealth Mode button can be used to prevent your computer from responding to ping messages that are sometimes used by attackers to identify potential targets.
Any changes you make to the firewall settings have to be confirmed by clicking the OK button at the bottom of the window
Support on the Apple website can be found here:
Info about the application firewall: https://support.apple.com/ en-us/ HT201642
To change Firewall preferences on a Mac: https://support.apple.com/ en-gb/ guide/ mac-help/ mh11783/ 10.15/ mac/ 10.15
Other firewalls
Other firewalls are available either to download or as software packages that can be bought from retailers.
Make sure that any software packages that you download have been fully evaluated by organisations that have the expertise to do such an evaluation.
Apps and software that you find using a search engine, or in an Android app store may contain malware.
You may prefer to use one of these programs, but if you do, please remember:
you should only keep one firewall running at a time since multiple firewalls will not offer significantly better protection and can interfere with one another
you must keep one firewall running at all times.
Once you’ve set up your personal firewall, identify a type of traffic that you might want to allow (or deny) on your computer.
