What is Linked IP

In order to associate a configuration with a network or a device, NextDNS uses different tricks depending on the DNS protocol used. For DNS over TLS (DoT), the configuration id is embedded into the hostname, for DNS over HTTPS (DoH), it is in the URL path and for UDP over IPv6, it is in the last bits of the IP. Unfortunately, for legacy UDP over IPv4, there is no such easy trick. Because IPv4 is a scarce resource, it would not be possible to attribute 2 IPv4 to every configuration. Instead, you have to associate the IP of your network with your configuration. We use a pool of IPv4 to let you link the same IP with different configurations if needed. You only need to link your IP when using unencrypted DNS over UDP/IPv4.

To link your IP, you just need to click on the link button in the setup tab of the interface. You will have to repeat this operation anytime your IP changes if it is dynamic. You can also opt for our DDNS solution: Instead of manually linking your IP, you give us a hostname that points to your IP, and use a DDNS solution to keep it up to date. The third option is to call a URL from a script whenever your IP changes.

6replies Oldest first
  • Oldest first
  • Newest first
  • Active threads
  • Popular
  • Linking my static IP with nextDNS account Web filters configuration will work and second can we use Nextdns DOH and link IP same time will work together?

    • tushar sharma you do not need link IP with DoH.

      Like 1
  • With DDNS linking it says it gets updated every minute, AFAIK most ISP's assign new dynamic IP's anywhere between 1-3 days & thus checking the IP every minute seems unnecessary use of your resources IMO. Could make it longer in the scale of hours maybe.

    This is just my thoughts, I am a novice so there might be a very valid reason to be checking the user IP every minute.

      • losnad
      • losnad
      • 1 yr ago
      • Reported - view

      Normally the ISP does not change your IP, at least in my country, unless you reconnect or if something happens on their side.

      If you restart your router or your electricity get interrupted and you get a new IP isn't normal for NextDNS to check for your IP as soon as possible? Would you wait for hours to be updated?

    • losnad Yeah makes sense, I was unmindful of what I was sharing as I personally don't have power issues and although I'm not paying for static, they only change IPs like once every 3 days or so.


      I also was unmindful of the fact that It's DNS which will anyway connect every minute when I'm active or apps and services using the internet in the background even when I'm not using them.


      Completely stupid question, my bad.

  • Can anyone share a script to call the URL to update the IP using DDWRT?