- Port Forwarding is the process of forwarding a specific port from one network to another, allowing external users to access the internal network by using that port from outside via a router (with NAT open -Network Address Translation).
- 1. Port Forwarding
- 2. Port and Protocol
- 3. Before configuring the Router
- 4. Some brand Router
- 5. Steps to set up Port Forwarding on the Router
Port Forwarding is the process of forwarding a specific port from one network to another, allowing external users to access the internal network by using that port from outside via a router (with NAT open -Network Address Translation).
Port Forwarding is widely used, especially for offices, schools and families with many computers connected to the Internet. The following article describes how to set up a port forwarding on a router.
1. Port Forwarding
Address the “inside” part of Network
Here’s how to get a simple Home Network map:
In the illustration you can see three computers with a single IP address on the same router. You can easily access other computers, however, when all of these computers access the Internet through a router.
Router has IP address related to your network. The router also has an external IP address that is used when interacting with your network. Whenever your computer requires Internet connection use the same IP address as 127.34.73.214.
2. Port and Protocol
Port (port) makes the process easier. If the IP address is the same as the address of a building, the port is the same as the number of each apartment in the building.
When you visit a Web site, suppose you are using port 80. The PC-aware software will know that port 80 is used for the http Server and meets your requirements.
If you send http on another port, suppose as Port 143, the Web server will not recognize and can not meet your request.
Secure shell uses port 22 and VNC uses port 5900. These port may vary depending on usage, as there are many specific programs that are used for different purposes.
In order to avoid affecting other standard applications, it is best to use larger alternate configurations.
For example, Plex Media Server uses port 32400, Minecraft Server uses port 25565.
Each port can be used via TCP or UDP. TCP, also known as Transmission Control Protocol, is the most commonly used protocol.
UDP or User Datagram Protocol is less commonly used in applications except BitTorrent.
Address the “outside” part of Network
What happens when devices outside the system ask for connection?
Suppose if your computer requires the Home Network 127.34.73.214 IP address, then connect to the router. However, Router does not understand to send back your computer.
In this case you can configure the router to forward the port. This means that depending on the number of port (s) required to be sent, the router can switch to other IP addresses.
When you access the Home Network IP address using port 22, your router will know that the address in the “inside” section of the Network is 192.168.1.100.
Then the SSH daemon installed on Linux will respond to you. At the same time, you can send requests through port 80, your router will send to the Web Server at 192.168.1.150.
Alternatively, you can remotely control your “sister” laptop via VNC, and your router will connect to 192.168.1.200.
When you access the Home Network through the interface port 80, you can tell the router to send 192.168.1.150. Web Server will listen to port 80 and respond to you.
However you can tell the router when you access through port 10000 that it has to access another computer, address 192.168.1.250 and port 80.
3. Before configuring the Router
Before configuring the Router, you need to pay attention to some of the following:
1. If you are using DHCP, the IP address of each device is likely to change in the future. In some cases, you must reset Port Forwarding.
So the best way is to reconfigure the static IP address of “server” (the host).
Some routers have the ability to “reserve” or “specify” an IP address through DHCP, so that the IP address will not be changed. However, not all routers are just a number.
2. When you access an external network, you must know the external IP address of the router.
You can easily discover someone’s address in the “inside” section of Network by visiting whatismyip.com. This address may change. One way to avoid changing IP addresses is to redirect the domain.
3. Use custom ports that can activate your antivirus programs, software or firewalls. You must therefore add an exception on the host computer to allow external access to any port that you specify. However, security risks will be compromised, so you should be careful and take appropriate preventive measures.
4. Some brand Router
– Cisco / Linksys:
You can see Port Forwarding under Applications and Gaming. Under Single Port Forwarding you can add individual ports to specify IP addresses.
Under the Port Range Forwarding entry, you can easily move the entire port range at the same time.
On the DLink Router you can find the Pord Forwarding setting under Advanced in the Port Forwarding tab.
The Netgear router has a menu of sections. Look in Advanced and then click on Port Forwarding / Port Triggering. If you use the Smart Wizard, you can configure Port Forwarding here.
Often, port forwarding in DD-WRT and third-party Router Firmwares applications and programs are included in the NAT/Quality of Service section.
Note that when you click Save to save changes on the DD-WRT Router will not take effect, you must also select Apply Setting.
5. Steps to set up Port Forwarding on the Router
Step 1: Enter your router’s IP address in the address bar of the Web browser
Enter your router’s IP address in the address bar of your Web browser to open your Router configuration page. Most IP address Router is 192.168.0.1 or 192.168.1.1 or 184.108.40.206. However, if you want to find your router’s IP address to make sure you can follow the steps below.
- For Windows: Open Command Prompt then enter ipconfig /all in the Search box. Your IP address is the same as the Default Gateway address.
- For Mac: Open Terminal and enter netstat -nr.
- For Linux: Open Terminal and enter Route.
Step 2: Enter your Username and Password
If you have set up Router protection then just enter the user name and password you created then proceed to login (Login). If you have not set up Router protection, follow the steps below to login.
- With the Linksys Router, type “Admin” in both Username (username) and password.
- For the Netgear Router, type “Admin” in the Username field and type “Password” in the password field.
- For other routers you can leave without entering the Username, the password you type “Admin”.
If you do not remember your credentials, you can press the Reset button on the Router to reset all of your defaults. Then look for the default information on the online settings.
Step 3: Search for Port Forwarding
For each router will be slightly different. You can usually find in Port Forwarding, Applications, Gaming or Viral Servers. If you still can not find it, go to the Advanced Setting section to find Port Forwarding.
Step 4: Find the available configuration items
On many Routers, there is a Dropdown Menu (which displays the content and is a main Main Menu, when you click it, it will display the Submenus inside) with the configuration options available for many applications. If you want to open Port for an application, select it on the list.
Step 5: Create a custom item
If the program you want to add is not listed in the list, you will have to create a Port Forwarding. For each router, the steps are slightly different, although the information required on the routers is the same.
- Enter the name of the application or program you want to add
- Select protocol: You can choose protocol as TCP, UDP or both. Protocol depends on which program you are unblock. If unsure, you can select one of two TCP or UDP protocols.
- Select the port you want to use. If you just want to open a port, enter Start and End the same number. If you want to open more Ports (about 5 Ports), you can enter 3784 in Start and 3788 in End.
- Select the internal IP address to assign to Port Forwarding. This IP address is the IP address that runs on the application you are unblocking.
Step 6: Save settings
To save your settings, select Apply instead of Save. Then restart your router.