Every home network is behind a router. The router ensures that all PCs in the home network have access to the Internet. If you want to access a device in your house from the internet, the router prevents that. You will have to open ports and grant access. How do you do that?
There is at least one router in every home network. This is often combined with the modem, but it is not necessary. The main job of a router is to route, that is, to route a network message or data packet through a network to get it from one place to another. Routers use the destination IP address that is contained in each network packet. They then decide very quickly whether that IP address belongs on the home network. If not, the router sends the packet to the provider's network. However, the router does a lot more. A second important function of a router is NAT (Network Address Translation): this is the replacement of the IP address of a network packet by another IP address within the home network. This is necessary because part of all existing IP addresses can only be used on the home network and not on the Internet.
The third important function of the router is the firewall. By default, the router will review any message coming from the Internet and will only pass it if it is a response to a message from a computer on the home network. All other messages are blocked, so the firewall protects the home network against intruders. Together, these functions provide a good connection to the internet, but they make accessing the home network from the internet a lot more difficult. However, you do want to access some devices within your home network from the internet, such as a NAS or a webcam.
01 Your own network
You may already know a few things about your network, but for port forwarding you should at least know the IP configuration of both the router and the device that you want to access via the internet. To explore the network, open a Windows command prompt: click the start button, type part of the word command prompt, and click the option Command Prompt. In the command prompt window, enter the command ipconfig from. This way you can find out your own IP address, the subnet mask, but also the IP address of the default gateway (that is the address of the router). The IP address of the NAS or IP camera is in the same network as the PC and the router. You can also use a network scanner like Angry IP Scanner. On your smartphone you can use an app like Fing (also for Android) to get this information.
To get to know the network, use the command prompt.
You can also easily find the IP address of the router with a smartphone and an app like Fing.
02 Login to the router
Management of the router is always done via the browser. Start the browser and type in the address bar the IP address of the default gateway, for example //192.168.1.1. Login with your username and password. Unlike the devices in the home network, a router has not one, but two IP addresses. The IP address on the home network side is the router's IP address as the default gateway. In addition, the router has an IP address on the Internet side, often called the WAN port. Both IP addresses can be found in the router's configuration. Write down the IP addresses, later you will need both. If you have set everything up correctly, use the external IP address (of the WAN port) to connect from the internet to, for example, your NAS or IP camera.
The router has two IP addresses, one for the internal network (LAN) and one for the Internet (WAN).
03 Fixed IP address
For port forwarding, it is important that the device that you want to use via the internet, such as a NAS or IP camera, can always be found at the same IP address in the home network. The device may therefore not obtain its IP address via DHCP, but must have a fixed IP address. This is also known as a 'static' IP address. You can set such a fixed IP address in the configuration of the NAS or IP camera. To do this, log in to the web interface of the device and open the network configuration.
Give all devices that you want to be able to reach from the internet a fixed IP address on the home network.
04 The theory of port forwarding
To set everything up in such a way that someone can see the images from the IP camera in the home network via the Internet, you need to know a number of information. Viewed from the Internet, these are: the IP address on the WAN side of the router, the IP address on the IP camera's home network, and the port number on which the webcam software is running on the IP camera. With port forwarding, you open a port in the firewall of the router (this can be port 80 or port 5000) and you link it to the IP address of the IP camera and the port number on the IP camera.
Then when you open a browser and make sure it really connects via the internet (not via the internal network) and type the address of the router in the address bar with the correct port number, the firewall will accept that connection and forward it to the IP address and the port number you specified in the port forwarding rule. From step 6 we will show you how to set up port forwarding for a number of popular router brands.
The iPhone and notebook both connect to a device on the home network, through a request to the router with different port numbers.
IP addresses
TCP/IP is the communication protocol on your home network and the internet. For example, when you open a web page, a large number of network packets are sent from the computer to the web server and back. The basis of this is the IP addressing. Every computer, NAS or IP camera has an IP address. Each address consists of four blocks of up to 3 digits each, from 0 to 255.
So all addresses are between 0.0.0.0 and 255.255.255.255, for a total of 4,294,967,296 IP addresses (2^32). Of all those addresses, a few blocks are only for use on private networks, they cannot be used on the Internet. These are 10.0.0.0 to 10.255.255.255, 127.0.0.0 to 127.255.255.255 and 192.168.0.0 to 192.168.255.255. This also applies to IPv4. There is now a successor in the form of IPv6, where there are enough IP addresses available to give each device a unique address. However, IPv6 is still hardly used.
