Double NAT is generally not desirable. Most often you connect to the internet through a single router that carries a public IP address assigned by your internet service provider (ISP) and creates an internal private network for your devices to connect using a private IP address.
Double NAT occurs when there are two routers connected both using private IP addresses. Very often this occurs when you connect your own router to a router provided by your ISP. This can also occur if your ISP used carrier grade NAT (CGNAT).
CGNAT is most commonly used by cellular and satellite internet providers. Double NAT can cause issues, especially with gaming as it prevents the devices connected to the first private network from communicating to the connected devices to the second private network. The most common way to fix the issue is to put your ISP’s gateway into bridge mode.
Bridge mode disables all router functionality and make your gateway operate purely as a modem, passing its pubic IP address to your router. This is the ideal way to fix double NAT. However it is possible to fix double NAT without enabling bridge mode.
There are a few different ways of fixing double NAT without enabling bridge mode. Here are a few methods that you can use to fix double NAT without bridge mode.
Eliminate Your Router
In many cases the gateway (router) provided by your ISP is more than adequate to provide all of the necessary features you need in a router. In this situation there may be no real advantage to plugging your own router into the gateway provided by your ISP. A simple option that will work well for some people is to simply ditch the second router and connect their devices directly to the ISP gateway. This option is also one of the few solutions that does not require purchasing anything at all.
This option is now however ideal for everyone. If you are the type of person that want max control and visibility into your home network you will want to use your own router. Using your own router is also useful if you need more coverage than what your ISP gateway can provide. However there are options for adding coverage without using a second router that we will discuss.
Replace Your ISP’s Gateway With a Straight Modem
Another option that will work for some people is to replace the gateway provided by their ISP with a straight modem. A modem has no routing functions and will pass your public IP address directly to your router and eliminate the double NAT problem. Depending on if you rent or own the gateway you use with your internet service you have a couple of options.
If you rent the gateway from your ISP you can reach out to them and ask if they could swap out your gateway with a straight modem. Most ISP’s will offer this option. Comcast, Spectrum, Verizon, and AT&T all offer this option.
If you own the gateway device that you use to connect to the internet you may want to consider replacing it with a straight modem if you wish to use a separate router. Contact your ISP for a list of approved modems. The modem you purchase will need to be approved to work with your internet service provider (ISP) in order for them to activate it on their network.
If you currently rent a gateway from your ISP this may be a good reason to consider purchasing your own modem. My purchasing your own modem you will eliminate the rental fee off your monthly internet bill. This could range anywhere from $7 – $20 per month depending on the provider. In many cases purchasing your own modem will pay for itself in just a few months. Contact your ISP for a list of approved modems. Check out our modem recommendation below.
Recommended modem for Comcast, Spectrum, Cox, Mediacom, and Atlantic Broadband. Compatible with all speed tiers including gigabit plans.
This is the ideal option if you wish to use your own router as it eliminates the possibility of having a double NAT issue entirely.
Use a VPN Service
The third option that can be used to fix double NAT is to use a VPN service with a public IP address. This is a great option if you are unable to get a straight modem and absolutely want to use your own router connected to your ISP’s gateway. This option works work especially well if you only have a single device such as a gaming PC that is having the issue. The key to success with this option is to use a quality VPN service provider. A free VPN will do more harm than good in this situation. You will need to invest a few dollars per month into a VPN service.
If your ISP uses CGNAT a VPN is likely the only way to eliminate double NAT issues. If you are connecting to the internet using a mobile hotspot, satellite provider such as Starlink or HughesNet, or a fixed wireless connection, your ISP almost certainly uses CGNAT technology. Bridge mode alone will not work with CGNAT.
The VPN service that I use and would highly recommend is ExpressVPN. I have tested over 15 different VPN services ranging from great to terrible. ExpressVPN is the fastest and most reliable VPN service that I have tested. They also offer a 30 day money back guarantee. If you do not like the service, you do not pay anything at all. Another bonus to ExpressVPN is that they offer servers globally which can be used to access geo-restricted content. If you wish to access for example region specific streaming services ExpressVPN is a great option.
Extending Wi-Fi Coverage
If the sole reason you are connecting your own router to the gateway of your internet service provider (ISP) is to extend your wireless coverage you have a few options. The first option which is completely free of charge is to configure your wireless router into access point mode. Most routers have this functionality and the setup process is quite simple.
Another option is to purchase a wireless access point and connect it to your ISP’s gateway. This is the preferred option and will provide the optimal results. If you only need to connect a single device such as a game console or gaming pc located away from your router you may want to check out powerline networking. I explained the basics of powerline networking in the link below.
Double NAT is generally not desirable for most people especially for gaming. Depending on if your internet service provider (ISP) uses CGNAT technology one or more of the options outlined in this article may work for you. Also note that using bridge mode is often the best solution and usually is as simple as calling your ISP and asking them to enable it.
Learn More About NAT: Gamers Ultimate Guide to NAT Type