As part of our help series we are going to be answering questions that we get asked about certain IT and Telecoms related products and services.
This piece, as you have probably gathered by the title is all about firewalls.
Q1. What is a firewall and how does it work?
A1. A firewall is a security barrier that sits at the gateway to your network or to your PC. The firewall works by both restricting and directing traffic based on a set of rules that you configure to suit your requirements. Its purpose is to stop unwanted access to your computer or network from the internet. It does this in one of 2 ways:
- Block or redirect – This includes protocols and ports
- Filtering traffic based on context – This could be IP addresses, domain names or keywords used
Q2. How does a firewall know what to block?
A2. Firewalls work on a set of rules set up by the user as explained above. Therefore, you decide what the firewall should block and what it should let through. For the traffic that is allowed through, it will then direct it to the appropriate destination computer
Q3. I have been told that Windows comes with a firewall, is that true?
A3. Yes this is true. All of the current Windows operating systems come with a firewall, although it is worth noting that they don’t automatically block outgoing traffic by default. Windows is also the most commonly attacked firewall by hackers so we would recommend that you don’t just rely a Windows firewall to protect your network.
Q4. Will a firewall block everything?
A4. No, it depends on the rules that have been set as to how much a firewall can block. Also some firewalls are not be able to block viruses, malware or phishing scams that are attached to emails as they cannot determine the content of the email. You should never click on an .exe file in an email, and always use antivirus software for this reason
Q5. What is the difference between a software firewall and a hardware firewall?
A5. A software firewall will be a program or application installed on your machine. In many cases it will be located within the operating system you are using i.e. Windows. A hardware firewall is a physical device that has been designed as a firewall and would normally be installed at the gateway to your network, for example in a router
Q6. Which is better, firewall software of firewall hardware?
A6. You can’t really compare them as they have different purposes. A software firewall will normally just protect the computer that it is installed on, where as a hardware firewall will protect the whole network. Hardware firewalls are generally more powerful in what they can be configured to protect against and some are very expensive devices.
Q7. Can I have more than 1 firewall?
A7. Yes. You would normally have some form of hardware firewall at the gateway to your computer network and then every PC within your network could have a software firewall proving a second level of protection
Q8. Will my firewall within my broadband router work on mobile devices connected through WiFi?
A8. Yes, all devices on the network (including all WiFi connected devices) will be connected to the internet via your router and as such will be protected by the routers built in firewall
Q9. Can I use the firewall to block any sites that I don’t want my staff to access?
A9. This depends on the firewall. Basic firewalls may not have this functionality but business grade firewalls will be able to perform content filtering and can block access to types of websites. Many companies use firewalls to prevent staff from being able to access sites such as Facebook, Twitter or other sites deemed not appropriate for work.
Q10. I have heard that my staff can get round the firewall using proxy servers, is this true?
A10. A proxy server is a server that accesses the website on your behalf and yes it is posibble to use a proxy server to disguise what website you are browsing and thus avoid being blocked by the firewall. That being said, there many business grade firewalls available which can also block access to these proxy servers.
So hopefully now we have answered a few questions that you might have about firewalls? If not, feel free to post a question in the comments below or give us a call on 0208 232 1190. We are always happy to give advice on any IT support issue.