Technical problems tend to be more or less the same: an online game that never connects, downloads that crawl at a snail's pace, strange errors from remote services. And that's when every tutorial points to the same goal: the famous port opening. If you want to know how to configure a router to open ports, today we'll share a guide that serves as a first step, but you'll need to verify several aspects of your network to succeed in this task.
How to configure a router: Difficulties
Unfortunately, opening ports is not something simple for the average user to learn. Once you gain some experience, the whole process becomes a matter of finding equivalences between different modem/router models, but if we have to talk about specific difficulties, there are two:
- Each manufacturer does what it wants with its products.
- Some providers refuse to allow changes to their devices.
The first point is a classic. Even the basic description of port forwarding is different. "Port forwarding", "port mapping", "port redirection", "port routing", "port mapping" and "virtual server" are some of the expressions manufacturers use to describe the same function. The bad news is that there is no interest in simplifying things. Most routers are low-cost devices with minimal profit margins, and they receive only one or two firmware updates during their official support period.
The second is the most irritating and frustrating. The hypothetical technicians on the other end of the line talk about "security and stability issues" to prevent port opening. Even worse, we've seen cases where a simple password change on the modem triggers a remote reset, restoring its factory settings. The solution is... to fight. You're paying for the internet service, opening ports is not illegal, and it's within the technical capabilities of any modem or router. Another possibility is to activate the so-called bridge mode and use a second router. If you can't get ports opened, maybe you can negotiate the use of bridge mode.
The first thing you should do...
The work to know how to configure a router with open ports begins outside the device, and the first requirement is to change the IP of the computer to a fixed value. In other words, you need to tell the network card to ignore the DHCP address and use a manual address. The reason is obvious: we don't want a moving target, and once we enter the configuration in the router, there must be some persistence in the values. Otherwise, the "open" state could change from one session to the next.
The guide we recently published explains how to modify the IP in Windows 10, but it also applies to previous versions of Windows, and some flavors of Linux. The general values are five: an IP address on the same subnet as the modem/router, the subnet mask (in most cases 255.255.255.0), the gateway which equals the IP address of the modem/router, primary DNS server and secondary DNS server (OpenDNS or Google work well).
The first three values are confirmed in Windows by opening a system console and running the command ipconfig. In your main network adapter you'll see the IPv4 address, the subnet mask, and the default gateway. You can repeat these values as long as the configuration is manual: the key is to remove DHCP from the equation. As for DNS, OpenDNS servers (208.67.222.222, 208.67.220.220) and Google (8.8.8.8, 8.8.4.4) work very well.
Now, a valid question is what happens with wireless network adapters. If we use public WiFi networks with a certain frequency, disabling DHCP is not a good idea, because we need the address assigned by the access point. Personally, I've noticed that users remember to return to automatic configuration before leaving, but most laptops also include an Ethernet card. Nothing prevents us from leaving the WiFi adapter on automatic, and configuring the Ethernet card to take advantage of port forwarding through a physical link.
How to configure a router to open ports on your connection
In the most generic way possible:
- Open your favorite browser and enter the router's IP address as the address. Once again, the ipconfig command should report this information as the default gateway. Many manufacturers use 192.168.1.1, but we've also seen 192.168.0.1, 192.168.100.1, and 10.0.0.1.
- Enter the username and password for the modem/router. The most common factory values are admin/admin or admin/1234, but sometimes they appear printed on the device label. There's also the possibility that your provider has changed both parameters, and you'll need to make a call to get them.
- Look for a section identified with the label "NAT" in the configuration menu. On some devices you'll find it quickly, while on others you'll need to explore the advanced section.
- Try to find a section with a name similar to "Port forwarding", "port mapping", "port redirection", "port routing", "port mapping", "virtual server", or simply "Ports". That's your destination.
- To open a port successfully, four basic parameters are needed: a name that defines the opening rule (whatever you want), the protocol type (TCP, UDP, or both), the port or range of ports you want to open, and the IP address manually assigned to the network card.
- Save the changes and restart the modem/router.
The first point is the simplest of all. The ipconfig command easily reveals its condition, and there's never a lack of manufacturers that reproduce all relevant information on the modem/router label. The configuration menu behaves like a normal web page, and if for some reason your browser gives you problems, try incognito mode or use another browser temporarily.
Finding out the username and password on a modem/router can be a matter of seconds, or turn into a real detective game. If no one configured it before, the admin/admin or admin/1234 combinations should work. The web is full of suggestions when we search for specific models, but if none of that works, the recommendation is to call support and demand the password. More experienced users often completely reset the modem/router and rebuild its configuration from scratch if the company refuses.
The third and fourth points leave us at the mercy of what the manufacturer decided. Some firmware is in English, others in Spanish, and others use a mysterious mix of English-Spanish-Chinese. Beyond the difficulties, the section to open ports should exist.
The fifth point to understand how to configure a router in port opening is the most technically demanding. Both the port and the protocol are defined by the application we want to use. If the plan is to download movies via torrent, in the qBitTorrent client a port under the TCP protocol is sufficient, but if you want to download with eMule, you'll need a port for TCP and another for UDP. Many routers allow port unification (by enabling options like "any", "all" or "TCP+UDP") and the use of port ranges. For example, it would be crazy to open individually ports from 20000 to 20050, and by applying the range 20000-20050 we save ourselves a huge headache.
Finally, there are models that can apply changes dynamically and without restarting, but before giving the benefit of the doubt, a reboot cycle clears any difficulty.
Conclusions
Yes, the text seems gigantic, but we insist: this is a superficial exploration. Configuring a router to open ports without addressing specific models presents multiple difficulties, and this is where you must intervene. After reading this information and getting a basic idea of the process, don't hesitate to go to Google and search for a guide to open ports on your modem/router. For example, YouTuber Mat Kairos did an excellent job describing port forwarding on the Askey RTV9015VW modem, a model that Movistar provides with its ADSL/VDSL service:
In summary: fixed IP, router configuration, NAT section, port forward, ports to open, and protocol. It may be difficult to achieve the first time, but once you know the whole structure, you can do it virtually on any modem or router you have in front of you. Good luck!
