Accessing CBW Modules from Internet
Learn how to access your ControlByWeb module from outside of your local network.
QUESTION: How do I access my ControlByWeb® module from the Internet?
The following is not a step-by-step tutorial in network and router setup, but rather provides a basic overview and tips for remote access that apply to common home and small office networks.
Accessing a ControlByWeb module from the Internet is a fairly simple concept, but it is highly dependent on your internet router (or modem/gateway) and your Internet Service Provider. There are literally hundreds of different combinations of routers and Internet Service Providers (ISPs). Your network may vary depending on setup. Consult with your network administrator, ISP, and/or router documentation.
Things you will need to be able to remotely access ControlByWeb devices:
- A ControlByWeb module that is configured and working on the local network. (The local network must have Internet access.)
- A public IP address. Most ISPs give their customers one public IP address which is accessible from the Internet. Some ISPs give their customers private IP addresses which are not accessible from the Internet. (If you are unsure if you have a public or private IP address, contact your Internet Service Provider or Network Administrator.)
- Assign a public IP address directly to the ControlByWeb module - or - Use a router with a public IP address and use 'Port Forwarding' to send specific traffic to the ControlByWeb module.
The following guidelines apply to setup a router that receive a public IP address from an ISP.
The router already handles all the traffic between your local network and the Internet, but now it must be configured to handle new traffic intended for the ControlByWeb module from the Internet. A simple way to achieve this operation can be done by configuring 'Port Forwarding' within the router.
To begin this process you must:
- Select a port to use. The ControlByWeb device uses port 80 by default, but any number between 1 and 65,535 will be valid. For security and reliability reasons, we suggest any port in the range of 2,000 to 15,000.
- Configure the router to forward a specific port to the ControlByWeb device connected to your router/modem (*Please see the router documentation for steps to enter the information for a 'port forward' in your specific router).
Most consumer and basic commercial routers offer two different types of port forwarding methods. For this document, they will be categorized as Simple and Advanced. (High-end, commercial routers may require additional steps. See your router documentation for your specific router settings and for more information.)
A simple router can forward any port coming from the internet to any IP address inside the local network on the same port number. The ControlByWeb device's HTTP port settings will need to be changed if any port is forwarded other than the default port (80).
For example, If you are using port forwarding and you typed in your external IP address like 126.96.36.199:9000, it would forward you to the IP address that you set it to on that same port (i.e. 192.168.1.2:9000)
An advanced type of port forwarding router can forward any port coming from the internet to any port on any local IP address. Usually this is referred to as 'port translation'. With ControlByWeb devices, the HTTP port can remain at port 80 (default). This means that if you were to type in the IP address of 188.8.131.52:9000 you could be forwarded to 192.168.1.2:80. (Notice how you are not on the same port that you originally typed in.)
Some potential issues when connecting to a ControlByWeb device from the Internet are:
Public Dynamic IP Address
Many residential and business Internet plans have a dynamically assigned IP address. This means that from time to time, the IP address given to you from your ISP will change. It is possible for the changes to occur as often as every few hours, or every few months between changes.
There are two ways to solve the dynamic IP address issue:
- Ask your internet service provide about a static IP address. Static IP addresses can be an additional cost, but rates can be as low as $3 a month. This option may not be available with your service.
- Sign up for a Dynamic DNS service (DDNS). A DDNS service allows you to associate a domain name with your IP address. You can then use the domain name to resolve the current public IP address of the network the ControlByWeb device is on. Depending on the service, your router may have the ability to automatically update the IP address for you. Additionally, some services offer PC software to update the IP address automatically.
NAT Loopback will allow the use the external IP address and port information from within the local network. The router will turn the query around and route it back into the local network. Some routers allow this function.
Some routers will not allow NAT Loopback. If your router does not allow this function, you will need to use the local IP address and port of the ControlByWeb when inside the network, and the external IP address and port when outside the network.
For more information, please refer to:
- Your router's documentation, users manual, or tech support.
- One of many free tutorials online for port forwarding (for example, www.portforward.com)
- The ControlByWeb device's users manual. (Many manuals includes an appendix labeled "How to access your device over the Internet.")