DNS, IP and Firewall Basics

Understanding the basics of DNS, IP addresses, and firewalls can help you troubleshoot issues, communicate clearly with support, and get a better grasp of how your network functions. Here's a quick guide to these core IT concepts.

What is an IP Address?

An IP address (Internet Protocol address) is a unique set of numbers assigned to every device on a network — like a phone number for your computer or printer.

There are two main types:

• Internal IP (Local) – Used within your office or home network (e.g. 192.168.1.10)

• External IP (Public) – Assigned by your internet provider and used to identify your network on the internet

You can find your internal IP by opening a command prompt and typing ipconfig.

What is DNS?

DNS (Domain Name System) acts like the internet’s phone book. It translates easy-to-remember domain names (like fusionit.uk) into the IP addresses that computers use to communicate.

If DNS isn’t working properly, you may not be able to access websites or cloud services — even if your internet connection is technically fine.

Common symptoms of DNS issues:

• Websites not loading but services like Teams or email still work

• Error messages like "DNS not found"

• Slow browsing or timeouts

What is a Firewall?

A firewall is a security system that monitors and controls incoming and outgoing network traffic. It can be:

• Software-based, running on your PC

• Hardware-based, built into your router or a dedicated appliance

Firewalls protect your network from unauthorised access and block potentially dangerous traffic — but if misconfigured, they can also block legitimate services.

Common firewall-related issues:

• Can’t connect to a server, printer, or cloud app

• Software updates or backups failing

• VoIP or remote access tools not working

Why This Matters

• DNS controls where your traffic goes

• IP addresses identify and route traffic to the right devices

• Firewalls determine what is allowed to pass through

Together, they ensure that your network is both functional and secure. If something isn't working, it’s often one of these three areas at fault.

Need Help?
If you're experiencing connection issues or unsure how to check your network settings, we can help you diagnose and resolve the problem quickly.

Ticket Portal: https://support.fusionit.uk
Email: support@fusionit.uk
Phone: 01244 835080

Disclaimer:
This article is intended as a general guide. While we aim to ensure accuracy, Fusion IT cannot be held responsible for any issues, data loss, or damage resulting from the use or misapplication of these instructions. If in doubt, please contact our support team before making changes.