pfSense- How to Get Rid of DNS Rebinding Warning





If you’ve ever used pfSense, you know how great it is. It’s jam-packed with features, its reliability is unparalleled, and it brings an advanced business-class firewall to us lowly home owners in need of something more than what a consumer router can provide. With that though, sometimes you run into issues you typically wouldn’t find in run-of-the-mill Best Buy routers.

One of these is DNS rebinding protection that’s enabled by default. In itself, DNS rebinding protection is a good thing to have enabled. This prevents an attacker from using your public IP address from within the LAN to gain access to your router configuration page through a malicious browser script, even if you have public-side access turned off.

If you use a software DDNS solution that comes built into servers such as WHS 2011 or a QNAP Turbo NAS and try to use it to log into your network devices from inside the LAN, you’ll see this warning.

It’s great that pfSense protects you from a DNS rebinding attack, but it’s also easier to log in using a domain name than it is typing the IP address of the device you want to access. Luckily, pfSense allows you to add an exception for just this scenario.

The Solution


The first thing you want to do is type your pfSense installation’s IP address into your web browser (this is the last time you’ll have to do this!). Once you log in, follow the slideshow below:

Slideshow- Tap or click to view

To fix this, first log in to pfSense with your LAN address. Click on System → Advanced


Make sure you’re on the Admin Access tab.


Scroll down until you see Alternate Hostnames. Enter your QNAP DDNS domain name. Scroll to the bottom and click Save.


Next time you log in using your QNAP DDNS domain name, you’ll get the pfSense login page instead of the warning!



I love pfSense. I love the capabilities it provides for my home network. I love not having to reset my router because it’s not working right (wish I could say thing about my Netgear Nighthawk wireless router !). If you’re intimidated by pfSense because it looks like it might be hard to configure- don’t be! Sometimes small annoyances like this warning can pop up, but they’re usually easy to fix if you know where to look.

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About Adam Bollmeyer

I'm a home technology enthusiast with a penchant for home automation, networking, and computers. My goal is to help others improve their knowledge of how available technology can be used at home.