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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.

17 replies

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    • tushar_sharma
    • 2 yrs ago
    • Reported - view

    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?

      • olivier
      • 2 yrs ago
      • Reported - view

      tushar sharma you do not need link IP with DoH.

    • ratkutti
    • 2 yrs ago
    • Reported - view

    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
      • 2 yrs 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?

      • ratkutti
      • 2 yrs ago
      • Reported - view

      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.

    • Ghani
    • 2 yrs ago
    • Reported - view

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

    • Mike_D
    • 1 yr ago
    • Reported - view

    Hello, I think my concern is appropriate to post here. I have subscribed to NextDNS so that ads do not pop up on Roku TV homescreen for my kids sake. I would like to learn how to keep my configuration linked to my IP. For some reason, I have to keep going back to my account on the NextDNS site and link my IP to my configuration over and over. Ads go away for awhile but then pop back up and have to relink. I have already changed my routers DNS addresses to the Next DNs ones.

    If someone could give me some steps or advice as to what to do, am I missing something? Thanks.

      • R_P_M
      • 1 yr ago
      • Reported - view

      Mike D Does your router support dynamic DNS? Your IP address is not fixed so every time you connect to the internet (or a reconnect) you will likely get a different IP. 
      NextDNS can’t directly detect this change unless you use the other connection protocols, like DoH, DoT and DoQ. 

      • Mike_D
      • 1 yr ago
      • Reported - view

      R P M thanks for your reply. Ounds like thats ehats happening. I'm not good with tech, is there a reason to pick one of those connection protocols over the others? If I could modify that on my router, Im guessing I just read my manual to see if its possible. 

      • R_P_M
      • 1 yr ago
      • Reported - view

      Mike D There is no real preference for any protocol, it’s just sometimes where one doesn’t work trying another does. 

      Please provide the make and model number of your router, someone may have experience of setting it up. 

      • Mike_D
      • 1 yr ago
      • Reported - view

      R P M 

      Thanks for the help.

      I have a Netgear AC2600 router.

      I was looking into the router settings and tried static DNS. That cut my connection off from the internet completely so my ISP mustn't support that. 

      • R_P_M
      • 1 yr ago
      • Reported - view

      Mike D You need Dynamic DNS not static. 

      In router settings the location is: Settings>AdvancedSettings>DynamicDNS.

      You will have to sign up to one of the services to use DyDNS. 
      Once you’re all set just use the dynamic DNS name you receive from the provider in the my.nextdns.io setup page, under linked IP.

      • Mike_D
      • 1 yr ago
      • Reported - view

      R P M thanks for your help.

    • Fiddlewink
    • 1 yr ago
    • Reported - view

    Hello, Is there a way to update the linked IP manually if you don't happen to be on that network at that time? I have a second network that I want to administer remotely.  Thx

      • R_P_M
      • 1 yr ago
      • Reported - view

      Fiddlewink Is there anything on that remote network running all the time, a server, computer or something? A Dynamic dns client updater can be set up to keep the IP current on a device.

      Even some routers can work with DyDNS providers. 

    • Matthijs_in_t_Anker
    • 5 mths ago
    • Reported - view

    At my site I have 2 ISP and thus 2 IP addresses. It appears Nextdns only supports 1 IP address for Linked IP. Since I distribute traffic across the 2 ISP (not working in backup mode) half of the network can not use Nextdns.

    Is there a way to link 2 (outside) IP addresses?

      • Martheen
      • 5 mths ago
      • Reported - view

       Easiest would be to run nextdns cli on a device in your network and set it as your local DNS resolver.